Concrete Landscaping
General Questions
Planning Questions
Design Questions
Building Questions
General Questions
How do I purchase CCI Allan Block products?
Ordering CCI Allan Blocks products is as simple as calling one of our many dealers. To find the nearest dealer, click on the “Dealer Locator” icon.
Why should I use CCI Allan Block for my landscape project?
For more than 15 years Allan Block has made it easy to Plan, Design and Build landscape walls of distinction. Allan Block has a solution for almost any landscape application. View the CCI Industries publications Garden Walls and Landscape Walls for some great ideas.
How high of a wall can I build with Allan Block?
Allan Block walls have been built over 40 feet in height (12.2m). More practical landscape walls, 6 feet in height and under (1.8m), are made easy by following the CCI Industries publication Garden Walls or the Landscape Walls.
Do I need a concrete footing for the blocks?
No. CCI Allan Block is designed to sit on a compacted granular base. This saves time and money while providing a solid base for the blocks. See the Garden Walls or the Landscape Walls for the recommended depth and width of base for your wall.
How long will CCI Allan Block last?
We know that standard concrete building blocks made in the 1950s using a similar process are still performing in building structures around the world. With the improvements in technology used today, we believe CCI Allan Block units will last a lifetime.
Are the blocks safe for the environment?
Yes. The CCI Allan Block units are made using natural, raw materials and are safe to use in the environment. No harsh chemicals such as those found in treated timber are in CCI Allan Block.
Can I cut a CCI Allan Block?
Yes. Blocks can be easily cut using common tools to give your wall a professional appearance.
How does CCI Allan Block stack up?
CCI Allan Block is a dry stacked system; no mortar, glue or pins are necessary. The blocks are formed with a unique, raised front lip that acts as a guide to automatically setback and interlock the blocks, as they are stacked.
Why do the blocks setback as they are stacked?
CCI Allan Block units setback as they stack to improve the stability and performance of the wall. They are designed with an automatic setback of 3, 6, or 12 degrees of "lean" into the hillside. The top lip and bottom notch combine to form the automatic setback. No measuring is necessary. Block setback is noted on all CCI Industries publications.
How much does CCI Allan Block cost?
CCI Allan Block cost varies depending on the style of wall you choose. CCI Allan Block walls are competitive with timber and stack rock, while costing up to 30 percent less than walls requiring concrete footings. Call a Certified CCI Allan Block Dealer for an accurate quotation on your project.
How does the cost of CCI Allan Block compare to other landscape walls?
Consider the options: landscape timbers, stacked rock, poured concrete or mortared solutions. CCI Allan Block is cost competitive with all these options.
- Consider the value of CCI Allan Block:
- Will not rot or decay - lasts a lifetime.
- Does not require any special fasteners such as nails, pins, or
clips.
- Dry stacked - no mortar and no concrete footing.
- Curved or straight walls are virtually the same cost.
- Different looks, colours and styles are achievable with very little
cost difference.
- Allan Block makes it easy - A complete solution.
Where do I buy CCI Allan Block?
Allan Block is typically available through landscape supply dealers or building material outlets.
How easy are the blocks to handle?
The hollow core, raised front lip and wing back design of the CCI Allan Block system makes them very easy to lift and stack. Blocks are available in different sizes, styles and weights. Ask your local CCI Allan Block Dealer for a demonstration on the ease of building with CCI Allan Block.
What is the white residue coming out of the block?
The white residue is Efflorescence. Efflorescence is a naturally occurring deposit resembling white frost that can sometimes appear on any product made with cement. This includes paving stones, retaining walls, masonry block and even concrete. This problem can cause some concern for the consumer as it temporarily detracts from the appearance of their project. While efflorescence is a temporary problem it is almost impossible to prevent. Efflorescence occurs when the water-soluble minerals contained within the product itself, mortar or backfill are dissolved in water. The minerals are then able to migrate from the block to its surface through small pours. When the moisture containing the minerals reaches the surface of the product and evaporates it leaves behind mineral deposits that resemble frost. Water from sources such as rain, sprinklers even dew can continue to penetrate the product and dissolve minerals. Causing the process to start over again for as long as there are free minerals in the product or water is still present. In climates that experience a lot of rain followed by sun this process will run it course a lot quicker than in semi arid climates where it can take a year or two for the supply of free minerals to be exhausted. There are a few things that can be done in the mean time while you are waiting for the problem to go away. Eliminate the water source if possible. After your Product is dry you can brush the white deposits off with a stiff brush. Another option is washing the product off with water, though this can give mixed results. Water applied to the product can dissolve the minerals on the surface and pull them back into the product as it soaks up the water causing the process to take longer. The last way to deal with the problem involves washing the product with a week solution of muriatic acid. This solution however comes with several problems. Any acid can pose a risk to the person applying it to the product. All safety and environmental factors must be taken into account before using this method. The last problem with using acid is that it actually changes the surface of the product and in doing so cause the color to change as well. We recommend that you allow nature to take its course and use a stiff brush when white frost appears. The disappearance of the efflorescence will occur in its own time.
Planning Questions
What do I need to know as I plan my landscape wall?
Review the Landscape Walls Brochure to consider soils, slopes, surcharges, block style and wall heights in the planning of your landscape wall project.
How do I choose the right CCI Allan Block product for my project?
CCI Allan Block has a size, weight, and style that are right for just about any landscape. Use the “AB Product Selection Guide” in the Landscape Walls publication to choose the style that best complements your project.
Can I build on uneven or sloping ground?
Yes. CCI Allan Block easily adapts to a sloping base. Starting at the lowest area, simply step the blocks up as you build into the slope. See the Landscape Walls publication for reference.
Do I need a permit to build a wall?
Contact your local building code department to see if building permits for landscape retaining walls are required in your area.
Can I build a wall in water? (ie: A pond or a lakefront?)
Yes. CCI Allan Blocks design flexibility makes it the perfect choice for water front applications even in areas where freezing is a concern. There are special considerations that your local CCI Allan Block Dealer can help with.
Can I plant a garden or landscape around the blocks?
Yes. Planting or landscaping in the block cores or behind the blocks is easy and environmentally safe. CCI Allan Block does not leach any harmful chemicals that could affect your plants or shrubs. A drip irrigation system can even be built into the wall during construction.
Can I build a fence on top of a wall?
Yes. Fences can be built in the blocks hollow core or behind the wall. The wall may have to be reinforced to support the wind load from the fence. Call your CCI Allan Block Dealer for help.
How many blocks do I need?
The number of blocks needed depends on the unit size of the CCI Allan Block you have chosen and the size of your project. Typically by multiplying wall height by wall length you can get a square foot area. Divide the area by the unit size to get a rough estimate. There are quick estimating guides on the Garden Walls and Landscape Walls publication and your Allan Block Dealer is also trained to help you calculate your requirements. Be sure to include corners (left hand & right hand) and caps if required for your project.
How much do the blocks weigh?
CCI Allan Block is available in a variety of different weights from under 30 lbs (14kg) to over 75 lbs per unit (34kg). Heavier blocks are typically designed for taller walls. Unique to CCI Allan Block is the blocks hollow core that makes them easy to lift and stack. CCI Allan Block unit weights are listed in several CCI Industries Publications.
What tools will I need?
There is a suggested tool list in the Landscape Walls. Tools required depend on the size of the job. Small walls may only require some basic tools such as a shovel, rake, wheelbarrow, small sledgehammer, 3" chisel, level and hand tamper. Larger or more detailed walls may need additional equipment such as a plate compactor and a diamond blade saw for cutting. Discuss your project with your CCI Allan Block Dealer for advise on tools and equipment to make your project easy. Some CCI Allan Block Dealers rent tools and have cutting services for your convenience.
Design Questions
What do I need to know as I design my wall?
Consider style and function as you initiate your landscape wall design. Review the Garden Walls and Landscape walls publications as you consider stairs, terraces, and finishing details.
What are my color and style choices?
From the natural antique appeal of Europa, to the marbled color of Ashlar, to the clean look of the AB Collection, CCI Allan Block has colors and styles that complement any landscape. See the Garden Walls and Landscape walls publication and choose the look that's right for your project. Call your local AB Dealer to confirm colors and styles available in your area.
Can I design and build stairs?
Yes. Stairs can be designed and built using curves or corners in a number of different styles. See the Garden Walls and Landscape walls publications for some great ideas on stair designs and construction details.
How tight a radius can I design and build?
Minimum curve radiuses are based on the block size, and are noted on the Garden Walls and Landscape walls publications.
What are terraced walls and how do they work?
Terrace walls tame a slope by building two or more low walls rather than one tall wall. Once the lower wall is built, the next wall can be constructed, leaving an area in between the walls for landscaping or planting. Ask Your AB Dealer for design assistance.
How do I finish off the top of the wall?
Unique to Allan Block is the raised front lip on the block that provides a perfect edge for landscape mulch, decorative rock or AB capstones. See the Garden Walls and Landscape walls publications for more ideas.
What does the term "Gravity Wall" mean?
A gravity wall is a wall that relies on its own weight to hold up the soil behind it. The weight of the blocks and the granular fill in the block cores, combine to become the weight of the wall.
What does the term "Reinforced Wall" mean?
A reinforced wall is a wall that uses layers of reinforcement grid to tie the blocks and soil behind the blocks together to form a larger and heavier wall.
How do I know if I need reinforcement?
The need for reinforcement depends on the weight the wall is holding back. See the pre-engineered "Soil Reinforcement Chart" in the Landscape Walls publication to see if your wall needs reinforcement.
What is AB Reinforcement Grid?
B Reinforcement Grid is a high strength polyester mesh that is coated with a protective black film and is conveniently available from AB Dealers.
Can I use lighting in the wall?
Yes. Lights built into the wall can provide a beautiful ambience to patios or add safety lighting along stairways. Use lighting fixtures designed for outdoor use and follow manufacturers instructions.
Building Questions
How do I find a professional Certified CCI Allan Block Contractor?
Your CCI Allan Block Dealer will be able to recommend a Certified Allan Block Contractor.
How do I get started?
After a quick review of your plan, the Landscape Walls publication and helpful "How-To" notes, you should be ready to start building your wall. Here is a short checklist: Order materials, gather tools, prepare the site and layout the wall locations and dig the base trench (starting from the lowest point). Follow the step-by-step installation guide in the Garden Walls and Landscape walls publication and don't hesitate to call your CCI Allan Block Dealer should you have any questions or need some additional help.
What are some good layout ideas?
- Use a garden hose to layout a smooth curve or as a "water level" to help
determine grade changes.
- Use a 3-4-5 triangle to build square from another structure.
- Mark utilities with a wooden stake or paint.
What kind of material should I use for the base?
A good base material is a crushed stone ¼" to ¾" in size. This material compacts well and makes it easy to level the base block.
Is compacting the base important?
Yes. A compacted base provides a solid foundation to build on and will not allow water to saturate the base material leading to a potential weakening of the base.
Is leveling the base block important?
Yes. The base blocks need to be levelled back to front and side-to-side.
Why should I bury some of the base block?
Partial burying the base block reduces the risk of erosion and potential undermining of the wall due the base being exposed. Bury a minimum of 1" per foot of wall height.
Do I need to stack in "running bond"?
No. "Running bond" refers to a pattern where the seam between any two blocks falls exactly on the centre of the block below it. Perfect running bond is not essential for CCI Allan Block walls. We recommend a minimum average offset of 3 inches. You can insert half blocks as needed to help maintain some staggering.
What kind of material should I use to fill the blocks and for the drainage behind the blocks?
You can use the same material as the base (¼" to ¾" crushed stone) although some contractors prefer to place ¾" clear crushed / angular stone because it is easier to work with.
When do I need to backfill?
Backfill every row of block you stack - and check your wall for level at the same time. Backfilling more than one row at a time may cause the wall to lean forward.
How do I use AB Reinforcement Grid?
AB Reinforcement Grid simply rolls out along the wall. Follow the installation instructions printed on every roll of grid.
How do I end a wall?
Ending a wall into a hillside, stepping down into grade or a combination of both are options to ending a wall.
How do I build corners?
Outside corners use the Allan Block 90 degree corner units. AB corners come in a pairs of a left and a right hand unit. As the left and right hand units are alternately stacked they form a strong interlock. Inside corners are formed using standard CCI Allan Block units. Part of the top lip on the blocks is removed so the blocks can alternately over lap on each other to form a strong interlock. See the Landscape Wall publication for details.
How do I make a corner cap?
Corner caps are typically miter cut with a saw on the job. Some CCI Allan Block Dealers may offer cutting services. (Allan Block does not manufacture a "corner cap unit") See the Garden Walls and Landscape walls publication for ideas on how to cut AB capstones.
How do I cut the blocks?
When it is necessary to cut a block use a saw with a diamond tipped blade. A better question is to ask is "how do I avoid cutting the blocks?" Good planning by way of project design and use different yet compatible sizes during construction is not only a time saver but also a "cut saver".
Do I need an engineer?
Generally, CCI Allan Block recommends the use of a licensed engineer on projects with taller walls or unusual site conditions. Local building codes may require the use of a licensed engineer for walls above a certain height. Our design charts and tables provide generalized engineering solutions. Each retaining wall site is unique, however, and specific evaluation will provide the most accurate solution.
Concrete Masonry
What is the correct way to specify a CCI concrete masonry unit? What is the "Four (4) Facet System" and how is it used to specify concrete masonry?
The Concrete Masonry section of the CCI website provides you with Specification Summaries, along with Product Formats and Master Specifications.
The Specification Summaries outline the prescriptive and performance benefits of CCI Firelite Block (Alberta only), CCI DuraBlock (Manitoba only) and the CCI Artisan and Artisan Lite along with CCI Terrazzo Block.
Concrete Masonry is specified using the requirements of CAN CSA A165.1-04. The ‘Four(4) Facet System” is the Canadian format designed to describe a concrete masonry unit, eg. H/15/A/M, where:
H = hollow
15 = compressive strength in MPa
A = density over 2000 kg/m3 with a maximum water absorption of 175 kg/m3
M = moisture controlled which means the cmu is cured, dried and wrapped.
You can use the following table contained in CSA standard A165.1 - 04 to specify these four physical properties of a concrete masonry unit.
What are the general guideline to height limitations of 10cm / 15cm / 20cm / 25cm / 30cm concrete masonry units for use in load bearing and non load bearing applications?
General guidelines or Empirical Design Rules for Unreinforced Masonry are included in the CAN CSA Standard S304.1 - 04 in Annex F (normative) as a mandatory part of the standard. They are based on a simplified analysis of the loads and forces acting on the structure. Limitations included in this approach are height, load location, seismic Zone, wind loading, openings and lateral support requirements. The Empirical Rules apply to non reinforced masonry only. Application of the Empirical Rules result in a structure that is 'deemed to perform' established by long term experience.
The Empirical Rules define the maximum allowable height of non reinforced concrete masonry walls using Table F.2 from Annex F of CSA S304.1 - 04: Allowable slenderness ratio and minimum thickness of masonry walls.
Note: For Cavity Walls, clause F.5.4 limits the total wall height to 6m above the floor of the first storey and the maximum spacing between lateral supports of 2.4m.
Based on empirical rules of table F.2: for a 20cm standard unit (190mm thick/wide) used in a loadbearing wall, the maximum wall height is 3.8m.
Similarly, based on empirical rules of table F.2: for a 15cm standard unit (140mm thick/wide) used in a partition wall, the maximum wall height is 2.7m.
What LEED categories can CCI Concrete Masonry qualify for? What are the determining factors in each category?
Concrete Masonry can contribute to the following LEED areas:
(SS 5.1) Sustainable Sites: Reduced Site Disturbance: Protect or Restore Open Space (Value: 1 point)
Segmental retaining walls (mortarless, stacked landscaping blocks) can reduce some site disturbance in landscaping projects by allowing natural contours of the site to be maintained. SRW units can also be used when replacing existing rotting timbers without having to disturb much surrounding soil.
(SS 6.1) Sustainable Sites: Storm water Management: Rate and Quantity (Value: 1 point)
Landscape paving stone can help contain storm water. Pervious pavers can function as hard surfaces while allowing water to percolate into the soil recharging local aquifers.
(SS 7.1) Sustainable Sites: Non-Roof Heat Islands (Value: 1 point)
Light coloured, high albedo (high reflectance, at least 0.3) paving stones can reduce the amount of on-site heat generated when the sun hits the pavement.
(EA 1) Energy and Atmosphere: Optimize Energy Performance (Value: 1 point)
The mass of concrete masonry can provide thermal storage (also known a thermal mass) that can moderate a building’s temperature. Concrete masonry can store heat energy and slowly release it, keeping the building cooler during the day and warmer at night. Thermal mass is more effective when used on the interior of a building and insulated to the outside. This is ideal for cooler climates such as western Canada. By using concrete masonry in this way, the heating and cooling needs of the building are reduced and less energy is wasted.
(MR 2.1 or 2.2) Materials and Resources: Construction Waste Management (Divert 50% or 75%) (Value: 1 point) Being modular in nature, concrete masonry is less prone to waste. Designers can maintain the rigour of modular dimensions, reducing cutting of units on site. Off cuts can be removed from job sites. Concrete masonry units can be reused and recycled or reused as filler and crushed aggregate or as landscape material.
(MR 3.1 or 3.2) Materials and Resources: Resource Reuse (Specify 5% or 10%) (Value: contributory)
One of the best reasons to use concrete masonry is its durability and potential for reuse and salvage. Dry stack segmental retaining wall units (landscaping blocks) and paving stone are the easiest to reuse. However, most concrete masonry units can be reused when carefully dismantled.
(MR 4.1 or 4.2) Materials and Resources: Recycled Content 7.5% or 15% (post consumer + ½ post industrial) (Value: 1 point) A portion of cementitious content in concrete masonry units may include a post industrial waste such as flyash. Products such as this one reduces the quantity of cement and thus reduces the quantity of cement and thus reduces CO2 emissions and increases the amount of recycled content. In addition, quantities of recycled aggregate can be used in some products.
(MR 5.1 or 5.2) Material and Resources: Local/Regional Materials 10% or 20% Extracted and Manufactured Locally (Value: 1 point) Concrete masonry producers manufacture locally within specific regions. In the LEED program, locally manufactured/harvested materials need to be from within a radius of 800 km of the building site or if shipped by rail, 2400 km.
(MR 8) Material and Resources: Durable Building (Value: 1 point)
Concrete masonry units are durable and contribute to building assemblies that remain useful in the materials cycle for long periods of time. The use of concrete masonry units, if properly detailed, will minimize the risk and environmental costs of premature failure of building components. Most deterioration occurs to exterior wall components. Therefore, good building envelope design is essential. (Canadian Standards Association) CSA S478-95 (R2001) - Guideline on Durability in Buildings” list concrete block firewalls with a design service life (DSL) of 100 years. Masonry durability is recognized CSA and should be part of the building envelope design.
For details regarding how specific CCI concrete products can be used to obtain these LEED credits, please
contact your local CCI masonry sales representative.
What is difference between the various methods of filling the block cores: (ZPMI) Zonolite Perlite Masonry Insulation, (EPS) Expanded Polystyrene ICON Inserts, Foamed in Place Urethane?
(ZPMI) Zonolite Perlite Masonry Insulation is a lightweight, free flowing, granular perlite, specially treated for water repellency. When poured into cores of concrete masonry units, it forms a fire rated, single component, uniform, non settling barrier to the transmission of heat, sound and moisture.
ZPMI provides the following thermal resistance R values when used in concrete block walls:
(EPS) Expandable Polystyrene ICON Inserts are molded from expandable polystyrene. The design of the inserts allows them to compress so they will fit the cores of all concrete masonry units with just one size. Inserts are placed in the cores of the block at the block plant. By placing inserts in the blocks, there is a significant improvement in the thermal efficiency of concrete masonry walls.
(EPS) ICON Inserts provide the following thermal resistance R values when used in concrete block walls:
Foamed in Place Urethane is a closed cell plastic foam with a refrigerant gas in the cell to give a high thermal resistance. It is ideal for insulating irregular shapes. It is manufactured on site by spraying or pouring the self adhering mixture of chemicals and foaming agent into the block cores. It is flammable and has high surface flame spread characteristics.
Foamed in Place Urethane provide thermal resistance (R) values similar to (ZPMI) Zonolite Perlite Masonry Inserts.
To obtain more information from the SpecData sheets for these products, please contact your local CCI Masonry Sales Representative.
What increase in fire rating can be achieved from filling the cores of a CCI Firelite® and CCI Durablock® standard masonry block?
Underwriters’ Laboratories Design No. U905 shows that a 2 hour rated 20cm concrete block (as manufactured by CCI Industries ) is improved to 4 hours when cores are filled with treated water repellent (ZPMI) Zonolite Perlite Masonry Insulation.
This means that in a fire, walls remain standing longer - providing greater time for evacuation, less damage to contents and extended protection for emergency personnel. In milder fires that do not destroy the wall, ZPMI simplifies the rebuilding process because reconstruction can begin with fully insulated walls already in place.
Is the use of recycled aggregates the only way to qualify for LEED points in (MR 4.1 or 4.2) Materials & Resources Category Credit 4.1 or 4.2)?
Quantities of recycled aggregate can be used in the manufacture of some concrete masonry products. However, to date, adding recycled aggregates into the manufacturing process is cost prohibitive.
Designers and building owners main objective of recycling in the manufacture of concrete products is the reduction in CO2 emissions related to the amount of cement used. A portion of the cementitious content in CCI Firelite Block and CCI DuraBlock units includes a post industrial waste. Since these products have cementitious physical properties, they reduce the quantity of cement and thus reduce CO2 emissions along with increasing the amount of recycled content.
The CCI Certification Form for Supplemental Cementing Materials is located on the CCI website in the section 'Concrete Masonry for Sustainable Buildings'. You may request the completed form by e-mailing:
info@cci-industries.com.
How do I quantify the acceptable color variance in concrete masonry?
There will be a variance in the colour of concrete masonry units due to many factors: colour variance in the raw materials, cement, aggregates and pigment colour; moisture differences in the aggregates; variation in the curing process and variation in the density of units from batch to batch. CCI Industries’ proprietary quality assurance process minimizes these potential causes of colour variation.
We recommend two strategies to quantify what is acceptable colour variation in the interior or exterior walls of your project. Firstly, visit completed projects that use the same type and colour of units that you have specified. View photographs of completed projects using the same concrete masonry units that you have specified. Secondly, include a requirement in your specifications to have a typical sample wall constructed of the specified concrete masonry units. These actions will confirm the colour variation that the specified concrete masonry unit can achieve and will avoid any surprises during construction. Your local CCI masonry sales representative will be pleased to assist you with this process.
What might be the installed budget cost of a 10cm CCI concrete masonry veneer application?
Traditionally, the installed cost of a concrete masonry veneer application has been approximately 2.5 times the cost of the concrete masonry unit. Given that the architectural concrete masonry unit costs $3.95, the cost of the installed wall would be about $10.00.
Given the buoyancy of current construction market, this cost may vary considerably. For a more accurate installed budget cost, we recommend that you contact your local CCI masonry sales representative. He/she will assist you in determining the specific cost information that you require.
How do I determine whether the block on site is CCI Industries product?
Every pallet of CCI concrete masonry is stretch wrapped. A label, affixed to the stretch wrap of each pallet, indicates the product name, code number, manufacturing location and the specific production run. There is also a product label affixed to the end board of the pallet. The pallets themselves are identified as 'CCI'.
CCI concrete masonry units do not contain an individual, identifiable mark.
If the above identification is not visible on the jobsite, it may be difficult to determine whether the concrete masonry units have been manufactured by CCI since a number of concrete block plants use the same or similar raw materials.
Normally, CCI grey standard units have a noticeable smooth appearance which is registered as 'CCI PaintPro' texture. This makes CCI concrete masonry units the easiest to paint. CCI architectural units have deep, rich colors due to the proprietary manufacturing process using CCI ColourFast pigments.
Your local CCI masonry sales representative will be pleased to assist you with this process.
What is the equivalent thickness method and how does it apply to fire ratings?
The ‘equivalent thickness method’ is used to evaluate the fire rating of a concrete masonry wall. The method is outlined in the 2005 National Building Code of Canada (NBCC), Division B, Appendix D ‘Fire Performance Ratings’. The material equivalent thickness required to achieve various ratings are listed in Table D-2.1.1
The equivalent thickness is the solid thickness that would be obtained if the same amount of concrete contained in a hollow unit were recast without core holes. The NBCC determines the fire resistance rating for concrete block masonry as a function of equivalent thickness, the type of concrete used in the block and whether the cores spaces are filled with grout or loose fill materials.
What kind of fire rating does CCI concrete masonry provide?
The fire ratings are calculated by the ‘Equivalent Thickness Method’ of NBCC as explained in the answer above. The maximum fire ratings of CCI units are limited by the equivalent thickness of each unit.
The basic CCI fire resistance ratings for standard lightweight concrete masonry units, CCI FireLite, with the 'CCI PaintPro' texture are as follows:
10cm 1.0 hours
15cm 1.5 hours
20cm 2.0 hours
25cm 3.0 hours
30cm 4.0 hours
Note that the above fire ratings apply only to CCI concrete masonry units manufactured with “Granulite” lightweight aggregates. They are not applicable to any other manufacturers due to specific internal dimensions of the unit and the type of aggregates used in manufacturing.
If you require the fire ratings of any other CCI concrete masonry units, please contact your local CCI masonry sales representative.
What is efflorescence? What is the cause? What remedies are there?
What is efflorescence?
Efflorescence is a natural occurring deposit of soluble salts and bases, usually white in colour, that sometimes appear on the surfaces of masonry or concrete construction. Although it may be an aesthetic concern, efflorescence will not affect structural performance.
Often efflorescence is apparent just after the structure is completed. If the efflorescence is essentially uniform throughout the exterior façade, it indicates normal water loss from the materials and the building. Some identify this occurrence as ‘early age’ efflorescence or ‘new building bloom’. If unattended, the salts will eventually be removed by rain water.
If the deposit is heavy and essentially shows as white streaks immediately below mortar joints or covering localized areas of the masonry, it indicates that water has entered or is entering the wall at a higher elevation. These salts are called leachates, referred to as ‘lime spots’, ‘lime runs’, ‘lime deposits’ and ‘lime leaching’ and are sometimes identified as ‘late age’ or recurrent efflorescence. Late age recurrent efflorescence usually consists of more permanent surface accumulations and indicates a need for corrective measures.
What is the cause of efflorescence?
As a natural occurring deposit, a combination of circumstances causes efflorescence. First, there must be soluble salts in the masonry. Second, moisture must be present to pick up the soluble salts and move them to the surface. Third, some force, evaporation or hydrostatic pressure, must cause the solution to move. If any one of these conditions is eliminated, the likelihood that efflorescence will occur will be significantly reduced.
For a more detailed explanation of the causes of efflorescence, please refer to this website Concrete Masonry Technical Information Efflorescence: Causes, Control and Removal.
What are the remedies for efflorescence?
Before any removal effort is made, the reason for the efflorescence should be established. If it is ‘early age’ efflorescence’, moist construction materials may be to blame. If it is ‘late age efflorescence’, the possibility of water leakage should be investigated. If the efflorescence is near ground level, ground water may be the cause. In any case, the problem should be repaired prior to removing the efflorescence. Generally, if efflorescence is the main concern regarding the masonry surface discolouration, the masonry walls should be allowed to cure and then the salts should be removed.
Compared to other stains, the removal of most types of efflorescence is relatively easy. Most efflorescing salts are water soluble and many will disappear with normal weathering unless there is some external source of salts.
In general, most efflorescence can be removed by dry brushing followed by flushing with clean water. If brushing is not satisfactory, it may be necessary to use a very light sandblasting or brush sandblasting to remove the deposits. Brush sandblasting is sandblasting which is light enough that coarse aggregate is not exposed by the sand blasting. Sand blasting needs to be done with care, as it can alter the appearance of masonry by roughening the surface. There are also a variety of commercial cleaners available which may be effective for efflorescence removal.
As a last resort, a dilute solution of muriatic acid (5 to 10 percent) is sometimes used to clean the wall. For integrally coloured concrete masonry units, a more dilute solution (2 percent) may be necessary to prevent surface etching that may alter colours and textures. Before an acid treatment is used on the masonry wall, the solution should be tested on a small, inconspicuous portion to be sure there is not adverse effect.
Calcium carbonate efflorescence is extremely difficult to remove. It appears usually as a flat white deposit and in the worst cases forms a hard white crust. Effective methods of treatment need to avoid altering the texture of the block. One method of removal that is effective is the use of a high pressure water jet, augmented with the addition of glass beads.
What are the causes of wall movement and how can they be controlled?
The prime concern with wall movement is that it can lead to cracking of the wall. There are four possible causes of wall movement:
Unequal foundation settlement
Extreme external forces
Abnormal distortion caused by expansion of other structural elements
Volume change in masonry due to temperature and shrinkage
Unequal foundation settlement, extreme external forces and the expansion of other structural elements can be minimized or removed by effective design and detailing.
Volume change in concrete masonry can also be treated by effective design and detailing. The volume changes are also be minimized by CCI Industries proprietary quality assurance program. Drying shrinkage or dimensional change in a concrete block resulting from change in its moisture content is an important physical property. The amount of linear drying shrinkage shown by concrete block masonry units can be reduced by effective curing, drying and storage of the units before they are shipped. It is one factor that will affect the frequency of placement of movement joints in the constructed masonry to reduce the likelihood of cracking.
'Control joints' are a stress relieving tool which should be employed in certain situations by the designer to accommodate the possible causes of wall movement explained above.
What are the rules of control joint location and how were they adopted?
AAs explained above, “Control joints” are a stress relieving tool which should be employed in certain situations by the designer to accommodate the possible causes of wall movement. Note that control joints are also described as ‘expansion and contraction joints’.
The use of control joints has been greatly reduced with the introduction of reinforcement into the masonry system. Some continuous walls are now constructed without control joints but certain details may require consideration by the designer.
Rules for the location of control joints have been developed from experience. Since there are many possible layouts of walls and partitions with their openings for doors, windows and ducts, judgment must be exercised in determining where the joints should be placed. The (ACI) American Concrete Institute recommendations for spacing of control joints are provided in the table below:
Control joints should also be located at the following points of weakness or high stress concentrations, as shown in the diagrams below.
i. at all abrupt changes in wall height
ii. at all changes in wall thickness, such as those at pipe or duct chases and those adjacent to columns or pilasters
iii. above joints in foundations and floors
iv. below joints in roofs and floors that bear on the wall
v. at a distance of not over one half the allowable joint spacing from bonded intersections or corners
vi. at one side or both sides of all door and window openings unless other crack control measures are used such as joint reinforcement or bond beams.
Note that for stack bond construction, joint reinforcement should be provided no further apart than 400mm.
All large openings in walls should be recognized as natural and desirable joint locations. Although some adjustment in the established joint pattern may be required, it is effective to use vertical sides of wall openings as part of the control joint layout. Under windows, the joints usually are in line with the sides of the openings. Above doors and windows, the joints must be offset to the end of the (bond beam) lintels. To permit movement, the bearing of at least one end of the lintel should be built to slide. (See control joint location figure above.)
When a concrete masonry wall is reduced in thickness across the face of a column, a control joint should be placed along one or both sides of the column. Thin concrete masonry across the column face should be tied to the column by means of dovetail anchors or another suitable device.
Where bond beams are provided only for crack control, control joints should extend through them. If there is a structural reason for a bond beam, a dummy groove or raked joint should be provided to control the location of the anticipated crack.
Where concrete masonry units are used as back up for another material with masonry bond, the control joints should extend through the facing. Control joints need not extend through the facing when using flexible metal ties.
Control joints should extend through stucco applied directly to concrete masonry units. Stucco applied on lath that is furred out from the concrete masonry requires control joints over previous joints in the base.
Do CCI concrete masonry units need to be sealed? What is the difference between sealing for water, air born contaminants and graffiti prevention?
CCI Concrete masonry units used as a veneer in a cavity wall system (with a non concrete masonry or concrete masonry back up) do not need to be sealed.
CCI recommends that a water repellant be applied to single wythe concrete masonry walls to assist in resisting rain penetration. Care must be taken to ensure that the appropriate product is applied. While exterior wall coatings resist rain penetration, they must also be permeable to the migration of moisture form the inside to the outside of the wall, so not to trap the moisture in the wall.
CCI Prime-A-Pell 200 has been successfully used in the western Canadian market for over 25 years to resist rain penetration. It is a clear, filmless, penetrating water repellent developed for use with exterior concrete masonry surfaces, both smooth and splitface. The treatment does not alter the colour or texture of the surface nor affect the vapour transmission qualities of the substrate. It is compatible with caulking and sealing compounds. The treatment creates long lasting water repellency and resists the following: water intrusion, stain damage, freeze-thaw spalling efflorescence, fungi and mildew. A limited five year warranty is provided against product failure. Experience has shown that Prime-A-Pell 200 needs to be reapplied every 10 years.
The use of a surface applied water repellant, however, does not minimize the importance of effective design details and construction procedures to resist rain penetration through the building envelope. These details are outlined in CSA Standards A370 - 04 "Masonry Construction for Buildings" and A304.1 - 04 "Design of Masonry Structures".
- Flashings, cavities, vapour barriers, air barriers, waterproofing membrane as well as sealants are used to improve the moisture resistance of a wall.
- Parging of the interior face of the concrete masonry or a few coats of oil based paint can sufficiently increase the resistance to air flow through a wall, thus reducing the chance of condensation of airborne moisture that can occur with the wall.
- It is generally acknowledged that superior resistance to rain penetration will result from the use of masonry cavity or veneer walls designed as open rain screens.
- For single wythe concrete masonry walls, rain penetration can be greatly reduced by constructing walls with full head and bed joints with mortar compacted in weather tight joints (i.e. tooled rather than raked) and walls that are free of cracks.
- The need for waterproofing concrete masonry walls can always be reduced by designing structures to keep walls dry and by good workmanship, especially in constructing mortar joints
- Water from the roof and other horizontal surfaces should be kept off the wall. Properly detailed roof flashings and sufficient height of roof curbs or parapets should be provided on flat roofs to force water to drain through drain pipes.
- Window sills and other projections beyond the exterior face of the wall should be sloped away from the wall and be provided with a drip to enable the water to fall free from the wall. In addition, through-the-wall flashings should protrude beyond the wall to provide a drip for water draining from the wall.
- Flashings should be used for any location where the potential exists for water penetration. Whenever flashing is installed, weep holes must be provided to allow water to flow to the exterior. Weep hole spacing is arbitrary but should not exceed 800mm. Weep holes should be provided in head joints immediately above the flashing.
- Constructors must follow the design such that water flow is always towards the weep holes. As such, cavities should be sufficiently free of mortar droppings to permit the weep holes to be open to allow for water drainage.
- Control joints should be generally positioned near openings and changes in wall direction where concentration of stress from restrained movement would otherwise likely cause cracking.
What are the disadvantages of sealing a concrete masonry wall?Q1
As explained above, CCI recommends that a water repellant be applied to single wythe concrete masonry walls to assist in resisting rain penetration.
However care must be taken to ensure that the appropriate product is applied. While exterior wall coatings resist rain penetration, they must also be permeable to the migration of moisture form the inside to the outside of the wall, so not to trap the moisture in the wall. If a ‘non breathable’ sealer is used trapping moisture in the wall, efflorescence will accumulate at the exterior wall surface. In cold climates, such as western Canada, freeze thaw cycles may cause deterioration of the exterior wall surface. As well, surface applied sealants need to be reapplied at specified intervals since they degrade over time when subjected to ultraviolet light.
As previously explained, CCI Prime-A-Pell 200 has been successfully used in the western Canadian market for over 25 years to resist rain penetration. It is a clear, filmless, penetrating water repellent developed for use with exterior concrete masonry surfaces, both smooth and splitface. The treatment does not alter the colour or texture of the surface nor affect the vapour transmission qualities of the substrate. It is compatible with caulking and sealing compounds. The treatment creates long lasting water repellency and resists the following: water intrusion, stain damage, freeze-thaw spalling efflorescence, fungi and mildew. A limited five year warranty is provided against product failure. Experience has shown that Prime-A-Pell 200 needs to be reapplied every 10 years.
How can a high lintel block be created using standard CCI Industries block?
A 20cm or 25cm single core lintel block can be used to create a high lintel. One end contains notches to allow for it to be removed with a mason’s hammer. The end should be struck from the inside of the block core to control the breakage of the face shell.
CCI Industries does not manufacture a 30cm single core lintel since it is seldom required. In the few cases where a 30cm high lintel is required in the design, one end and the centre web of a standard 30cm unit may be saw cut to create the high lintel unit.
How can I adopt a metric block to an imperial design?
In 1978, the masonry industry in Canada adopted the metric module for a concrete masonry unit with manufactured dimensions of 190mm (width) X 190mm (height) X 390mm (length) for a 20cm standard unit. The modular size (including mortar joint) is 200mm (width) X 200mm (height) X 400mm (length).
The former imperial sized units were 7 5/8 inches (width) X 7 5/8 inches (height) X 15 5/8 inches (length) for an 8 inch standard unit. These imperial measurements convert to actual metric measurements of 193.7mm (width) X 193.7mm (height) X 396.9mm (length).
The actual sizes of the metric block are therefore slightly smaller than the former imperial sized units. This results in an aesthetic issue when a metric sized addition or repair is being made to a concrete masonry building originally constructed using imperial sized units. The mortar joints (or block coursing) of the existing imperial sized units do not match with the metric size units to be installed.
There are a number of solutions:
A wall treatment may be designed to hide the connection between the original portion of the building and the addition. The new metric sized wall is installed with the standard 10mm sized mortar joints. This design feature minimizes the visual effect of the difference in block coursing.
The (smaller) metric block can be installed with wider horizontal mortar joints to match the existing imperial sized block coursing. The vertical joints can maintain the original ¾ inch size.
A metric block may also be manufactured to the higher imperial height, i.e. an additional 3mm in height. However, this height difference is difficult to maintain in the manufacturing process. It also requires a special manufacturing run for which a premium is charged and is subject to minimum quantities. For further information about this alternative, please contact your local CCI masonry sales representative.
How long does a Concrete Masonry designed building last?
CCI Concrete masonry units are durable and contribute to building assemblies that remain useful in the materials cycle for long periods of time, (particularly for institutional buildings such as schools and hospitals).
The use of CCI concrete masonry units, if properly detailed, will minimize the risk and environmental costs of premature failure of building components. Most deterioration occurs to exterior wall components. Therefore, good building envelope design is essential for a durable, long lasting building.
(Canadian Standards Association) CSA S478-95 (R2001) “Guideline on Durability in Buildings” list concrete block firewalls with a design service life (DSL) of 100 years.
The Canada Green Building Council (CaGBC), in its LEED Canada program, recognizes the potential for concrete masonry durability in (MR 8) Material and Resources: Durable Building. Since masonry durability is recognized CSA and applies for a potential LEED credit (MR 8), it should be part of the building envelope design.
Are all masonry veneers the same?
Masonry veneers can be designed and constructed using one of three basic products: architectural concrete masonry, clay brick and manufactured or natural stone.
Each masonry veneer type has it own physical properties. Concrete masonry and clay brick physical are detailed in their respective CSA Standards:
CAN CSA A165.1 - 04 Concrete Masonry Units.
CAN CSA-A82.1-m87 (R2003) Burned Clay Brick
CCI concrete masonry is a popular veneer choice of building owners, developers and designers because of its economy, design versatility and numerous colour options.
CCI concrete masonry veneers using a 200mmX200mmX400mm module are normally about 25% less expensive than other masonry veneers due to its larger modular size.
The versatility of CCI concrete masonry units can be used to create walls unique for each building since they are available in multiple colours, sizes and in a number of textures. The textures available include smooth CCI PaintPro - smooth texture, CCI StoneTex and CCI Terrazzo Block textures.
To determine which veneer shapes/sizes, textures and colours are available in your location, refer to cci-industries.com. Click on Concrete Masonry to download the CCI product line in your location.
CCI concrete masonry is manufactured to inventory based on sales forecasts of product requirements. This means that CCI has the product for you to start your project right away. For more specific details, please contact your local CCI masonry sales representative.
In a single wythe wall assembly, what advantages do integral water resistant additives add?
CCI uses proprietary integral water repellant chemical admixtures in the manufacturing process: CCI EffloStop and CCI WaterStop. These admixtures are designed specifically for the CCI manufacturing process. They are effective in reducing water migration throughout the concrete masonry units and also reducing the potential for efflorescence.
A compatible chemical admixture should also be incorporated into the mortar at the jobsite since the mortar joint is the weakest link in the system for water penetration.
In Manitoba, CCI manufactures a proprietary EGB - exterior grade block - for all its exterior wall applications. These CCI products have proven to show superior resistance to water penetration.
Are there restrictions on installing cmu units in lower temperatures?
The requirements for installing concrete masonry units in cold weather (Cold Weather protection Requirements) are contained in CAN CSA Standard, A370 -04 “Masonry Construction for Buildings”: Clause 6.7.3.1:
The amount of insulation required to properly cure concrete masonry in cold weather is determined on the basis of the expected air temperature and wind velocity and the size and shape of the structure.
A protection period specified in Clause 6.7.3.1 may be decreased from 48 to 24 hours if high early strength Portland cement and Type S hydrated lime are used in the mortar. When types N and O mortars are used, the protection period shall be 48 hours in all cases.
What kind of sound ratings does CCI concrete masonry provide?
Background:
The difference in sound levels from one side of a wall to the other indicates the loss of sound transmitted through the wall. If the sound generated inside a room is 80 decibels (db) and 30 db is measured on the other side of the wall (adjoining room), the reduction in sound is 50 db. A test which relates sound loss through a wall at various frequencies plus certain averaging, provides a single value for a wall for comparison with other wall subjected to the same test. This value is the STC, Sound Transmission Class.
Considerable test data is available to show that STC ratings for concrete block are directly dependent on the mass of the wall. The compilation of test data is contained in the graph below (ref. NCMA TEK 13A.) Curves drawn on the graph represent the average relationship between STC rating and wall weight for painted concrete masonry walls masonry walls with gypsum wallboard applied directly to the surface.
Sound Transmission Class (STC) Ratings:
Note that unpainted lightweight block with a CCI PaintPro ™ texture exhibits very good sound absorbency characteristics at the expense of somewhat lower STC ratings. As paint is applied to seal the surface, the STC ratings increase significantly and the sound absorbency value is lessened.
From this graph, the STC ratings for CCI standard concrete masonry units have been estimated and are shown in the table below:
Reliability of Concrete Masonry STC Ratings:
An important asset of concrete masonry in noise control is its reliability. Unlike the so-called ‘special’ partition constructions which are touted as sound barriers, concrete masonry walls require no special installation procedures to be effective. All too often the staggered stud isn’t staggered; the decoupled membrane ends up rigidly connected; and the floating wall is sunk by poor workmanship in the field. The specially constructed stud wall that had an STC of 45 in the acoustical laboratory ends up with an STC of 15 in the field because of improper installation. This does not happen with concrete masonry walls. Designers know from experience that the concrete masonry wall is not as sensitive to workmanship and can be relied upon to act as an effective noise barrier.
Sound Absorption:
Sound absorption involves the reduction of sound within a room. The surfaces of a concrete masonry wall can absorb a certain portion of the sound rather than reflect the sound. Sound striking the surface of an open texture concrete masonry wall is trapped in the small pores of the concrete. A test at various sound frequencies determines the sound absorption coefficient or Noise Reduction Coefficient (NRC) and is an indication of the sound absorbing efficiency of the surface. If a surface could absorb 100% of the impinging sound, the wall would have a noise Reduction Coefficient (NRC) of 1.0. A wall which is coated with paint or stucco closes these pores and prevent the concrete masonry form absorbing sound. Listed below are approximate NRC for concrete masonry units:
Can a curved or radial wall be constructed from standard concrete masonry units? How might this be done?
The use of concrete masonry in the design and construction of radial walls presents a unique challenge to the design professional.
Where curved walls once were formed from hand hewn stone carved to fit a predetermined radius, radial walls of concrete masonry are usually formed from rectangular units of fixed shape and dimension. The end result is a series of short chords rather than a smooth arc. The greater the radius, the more closely the surface formed by the chords approaches that of a true arc.
The curvature of walls so constructed is dependent upon such variables as length of unit, thickness of units, width of the vertical head joints at the interior and exterior faces of the wall and whether the units will be used as is, beveled at the ends or cut to conform to the desired radius.
The minimum radii for curved or circular walls constructed of concrete masonry units is determined through iterations of the plane rectilinear geometric formulae for regular polygons. NCMA TEK 5-10 provide the explanation of how to calculate the minimum radii along with examples of minimum radii for specific sizes of concrete masonry units.
Does concrete masonry support the growth of mould?
A Canadian research study completed in September 2003, has shown definitive results that concrete masonry does not sustain mould growth, while wood and drywall products are sources of mould growth.
The standard used, MIL-STD 810E, was developed for the US Military (same as ASTM C1338) but includes a condensation period of 28 days to challenge materials. This is representative of conditions inside buildings in a cold climate. The testing, conducted by a ISO/IEC 17025 accredited independent laboratory with ISO 9002-1994 included seven samples of commonly used building materials The results were as follows:
For complete details of this research, please refer to cci-industries.com: Green Concrete Masonry Fungal Mould Resistance Testing (FMRT) of Common Building Materials According to MIL-STD 810E.
Pavers & Slabs
Is the base material important?
Yes. The base material absorbs the loads applied to the surface of the pavers. Without the compacted base the pavers could fail by rutting or sinking.
What type of material is used for the base?
The proper material is a crushed angular gravel mix typically referred to as a ‘crushed miscellaneous’ or ‘3/4 minus’.
What is the geotextile and is it necessary?
Geotextile is a heavy fabric that functions similar to a coffee filter. As water goes in and through the base it prevents the base from migrating into the existing soils. It may be necessary in areas with high water tables.
Is the bedding sand used for leveling the pavers?
No. The bedding sand should be loosely and evenly screeded at a depth of 1 to 1 1/2 inches. It fills the joints from the bottom up and allows for removal of minor height differences between pavers during the first compaction. It should not be used to fill depressions in the base material.
Is the joint sand different than the bedding sand?
Not always. Bedding sand can be used to fill the joints but may be difficult to sweep/vibrate into the joint. Dry bagged joint sands are typically finer, and sweep/vibrate easily into the joints assuring good interlock.
Are there dye lots with pavers?
Yes. Although typically not referred to as dye lots, pavers are made of natural materials which may cause minor color variations between pallets or batches. The contractor should lay the pavers from various pallets simultaneously to assure a good color mix.
Is the edge restraint important?
Yes. Without the edge restraint the pavers will not remain interlocked and could fail. There are many different types of edge restraints commonly used such as wood, metal, plastic, or concrete.
Do I need to seal the pavers?
No. Sealers, however, may offer benefits including color enhancement, joint sand stabilizing, and stain resistance. Areas such as pool decks and back patios are commonly sealed.
How long will interlocking concrete pavers last?
Typical residential installations will last 30 years or more, with little or no maintenance.
What are Interlocking Paving Stones?
It is the system of interlocking concrete pavers and not necessarily dependant on a specific shape of stone that creates the positive lock. When installed properly, the combination of the pavers, bedding sand, edge restraints and joint sand causes them to interlock, allowing them to work as a unified flexible pavement surface.
Are Interlocking Pavement Stones better than Poured in Place?
Interlocking paving stones are the ideal product for the freeze/thaw cycles we live in. Following the correct installation procedures they will provide you with a product that is both flexible and rigid in nature, yet easily removed for repair or access to utilities. The joints between each paving stone allow the walkway, driveway or patio to move without cracking. They are on average 3X stronger than regular poured concrete. Concrete pavers by specification and industry definition have a minimum compressive strength of 8,000 psi and a maximum water absorption rate of 5%.
Does the colour go all the way through?
Yes. All CCI Industries concrete paving stones are solid in colour. The colour pigment is mixed within the concrete mix before any of our paving stones are manufactured.
What is the "White Haze" on some of the paving stones and how do I remove it?
The white haze is referred to as "efflorescence", which occurs when the natural salts and minerals settle on the surface of the paving stones. This is quite common in all concrete masonry products. The best course of action is to do nothing and let Mother Nature take care of them, usually within a short period of time. There are chemicals to remove the efflorescence but only remove the surface salts and do not stop the process. Take caution when using these types of solvents as they are caustic and can damage the paving stones if used improperly.
How many paving stones do I need for my project?
Concrete paving stones are sold individually and are estimated in a square foot or square metre measure that is applied to each type of paving stone for easy calculations. Measure the total overall area you require and calculate this into a corresponding square foot or square metre reference. Add 5-8% to this total to cover splitting and or damaged paving stones during the installation process. Divide the total square footage by the paving stone manufactures specifications.
Should concrete pavers be set in mortar?
NO. It is not recommended that mortar be used; remember the nature of paving stones are to be flexible in nature. Concrete or asphalt bases can be used within specific commercial applications that support heavy vehicular traffic, not commonly found in residential use.
How are the paving stones shipped?
Paving stones are shipped on pallets ranging from 70-110 square feet depending upon the chosen size and shape. Each pallet will have a square footage coverage assigned based on the paving stone shape, thickness and quantities by each manufacturer. Average weight per pallet is 3,000 lbs so place them as close to your project as possible when they are delivered to your project sight. Partial pallets are also available from your local area retailer.
What do I use for base material and how much do I need?
A road crush material in a +/- ¾ size will ensure you get a proper mixture of larger and smaller gravel arts with the correct ratio of sand and fines (do not use a sand material for the base application). Depending upon the application this should be between 6 & 8 inches thick when properly compacted. As a rule of thumb, one ton of compacted base at a depth four inches thick covers about 50 square feet. The base should be compacted in 3-4 inch layers at a time with a plate compactor capable of at least 5,000 lbs of force. Do not try to compact the base in one life of 6-8 inches. Some applications can benefit from the use of a portland cement sand mixture (sandy soil and vehicular traffic applications) for the base course. The use of a geotextile material between the excavated area and base layer (heavy clay and silty soils and heavy vehicle traffic applications) provides an insurance policy against base failure. Do not use landscape fabric to replace the Geotextile material. When compacting the base, the material should be slightly damp (not dry or saturated) and spread evenly in depth across an area extending 6-8 inches past the actual edge of the concrete paving stones. This allows for the proper placement and anchoring of the edge restraints. The finish grade of the compacted base should be as level as possible and may require multiple rakings to achieve the preferred finish.
What is bedding sand and how much do I need?
Bedding sand is coarse concrete sand, commonly referred to as masonry or play sand which does not contain any stone dust or silts. The bedding sand is screeded in a 1 - 1 ¼ inch layer with a rail and board system to maintain level. Do not compact this layer of sand until after the paving stones have been placed into position and top-dressed with joint sand. Most applications can use the same sand used for the bed as that for the jointing. Rule of thumb measure is 1 ton of sand for every 100 square feet at a 1 ¼ inch thickness with a portion left over for use as jointing sand. Do not use limestone screenings or stone dust for bedding sand.
Will weeds grow between my paving stones?
Weeds and grass result from the seeds or spores blowing into the joint sand. Sealing the paving stones or use of a spot weed killer can reduce the growth, providing a weed and grass free patio, driveway or walkway application.
What are the advantages to sealing my paving stones?
Sealers offer 3 advantages: Helps to resist staining, enhancement of paving stone colour and helps to bind the sand in the joints. Sealers are a topical product and application will need to be repeated every 3-5 years. You should wait at least 60-90 days after the installation is complete before sealing your paving stones.
Can I place the paving stones on top of my existing sidewalk?
Two issues would need to be addressed before placement on top of existing concrete walkways. The condition of the existing slab along with the rise and fall of the slab within the freeze thaw cycle. Secondly, the grade of the walkway will be raised by about 3 inches based on the height of the paver and bedding sand used and may interfere with doorways.
How do I estimate edge restraints?
Edge restraints hold the paving stones tightly together, enabling consistent interlock of the units across the entire project. They prevent the paving stones from spreading due to horizontal forces from tires and minor settlement. Edge restraints are sold in many different styles and materials, so choose the best one for your specific requirements. Measure the perimeter of all areas that are to be retained by the edge restraints in lineal feet. They are available in various PVC and metal materials, straight and/or curve styles and holes for 3/8 by 8 inch steel spikes for securing in place. Poured concrete edging, such as curbs and gutters as well as the edges against buildings, should have landscape fabric placed down with a 8-10 inch overlap to help retain the bedding sand. Wooden, treated lumber edges are not recommended as they are temporary in nature, harder to secure and can become rotted and warped over time.
How can I find out more on paving stones?
Need help? Have a question? CCI Industries can help you contact your local representative. Your local hardware or building store retailer can also provide you with the information you may require for your project. The Interlocking Concrete Pavement Institute (ICPI) and any of their associate members (check your local yellow pages for their logo) are a great information source for paving stone applications. They are available on-line at www.icpi.org. Continue visiting www.cci-industries.com for the latest updates on paving stones produced by Canada’s Leading Choice in Concrete Products.
Natural Stone Masonry
Do Naturalstone Solutions products have a warranty?
Yes. The warranty on the stone is a 50-year limited warranty.
How does Naturalstone Solutions product hold up in the weather?
Existing applications shows no undesirable change after years of weathering.
How do you clean Naturalstone Solutions?
Using water and soap can often clean the surface of Naturalstone Solutions products. We do not recommend the use of a pressure washer.
Do you do installation?
We are more than happy to help you arrange installation with a qualified contractor. Please call us at 780-447-2122 to find out more.
What kind of surface do you need to apply Naturalstone Solutions?
The existing surfaces must present a firm and unified base for the veneer. On exterior applications it is recommended all wood surfaces and other surfaces not classified, as a "water barrier" should have a layer of 15 lb. felt paper applied before installing wire lath.
Can you seal Naturalstone Solutions?
Yes. However, we recommend a sealer that will not leave a residue which could detriment the look of the stone. Please call us at 780-447-2122 for recommended sealer options.
Can you use Naturalstone Solutions for walkways, patios?
No. Naturalstone Solutions products are not structurally designed for use on walkways, patios, drives, etc.
Can Naturalstone Solutions be used for water fountains and swimming pools?
No. Regardless of manufacturer, precast stone is not designed for constant contact or submersion with water.
Can Naturalstone Solutions products be cut?
Yes. Naturalstone Solutions are easily cut and trimmed using nippers, or with a diamond saw blade. However, if you do cut Naturalstone Solutions the color is not all the way through so you will have an unfinished edge. It is recommended that mortar be lightly applied to the cut edges.
What is the average thickness of Naturalstone Solutions?
1 ½" to 2" depending on the style and texture of the stone.
How much does Naturalstone Solutions weigh?
The weight of Naturalstone Solutions products is approximately 8 to 11 lbs per square foot.
Will Naturalstone Solutions products retain their color?
All natural iron oxides are utilized to manufacture Naturalstone Solutions. These oxides, which are the primary coloring elements, carry the same weathering characteristics as real stone. Under normal circumstances, and when applied per manufacturer's specifications, no undesirable change in color occurs after years of weathering.
Can I install Naturalstone Solutions myself?
Yes. If you accustomed to working with masonry tools and supplies, anyone can install our product by following the simple instructions on our Installation Specifications page.
