GETTING THE BEST FROM OUR MASONRY PRODUCTS
Advice on how to get the best results from concrete blocks, bricks, paving, garden edging and retaining wall systems from Cowra Concrete Products.
Do not wet blocks
Cowra Concrete Products should be dry when laid to minimise subsequent shrinkage.
Cleaning concrete masonry 
Keep mortar off the face of the blocks. Clean off droppings as work progresses and before mortar sets. Avoid cleaning down with acid whenever possible. Click here for the Concrete Masonry Association of Australia publication, Concrete Masonry Cleaning and Masonry, or pick up a copy from Cowra Concrete Products.
Colour – order enough product!
Take care to order sufficient product to complete the project all at once, to avoid the possibility of batch variations.
Control of shrinkage cracking
Cowra Concrete Products respond differently to moisture movement and temperature change than clay bricks. Assuming sound foundations are provided, cracks in walls can be avoided with the correct use of control joints, bond beams and/or joint reinforcement. Rules for the use of these elements are contained in Australian Standard 3700-2001.
Useful estimating data
Blocks with 390 x 190 mm face = 12.5 units per 1 square metre To fill 200 mm bond beams allow .013m3 of concrete per lineal metre of beam To core fill 150mm ‘H’ blocks allow .65m3 of concrete per 100 blocks To core fill 200mm blocks allow .8m3 of concrete per 100 blocks To core fill 200mm ‘H’ blocks allow .84m3 of concrete per 100 blocks To core fill 300mm blocks allow 1.1m3 of concrete per 100 blocks To core fill 300mm ‘H’ blocks allow 1.32m3 of concrete per 100 blocks
Mortar types
| AS 3700 Class | Cement | Lime | Sand | Typical Applications |
| M4 | 1 | 0 + .25 | 3 | High durability – use when in contact with earth, in retaining walls, below DPC’2, in fences adjacent to the sea, in capping courses to fences and parapets. |
| M4 | 1 1+ | .5 water thickener | 4.5 4 | Structural brickwork and severe exposure – fences – external walls adjacent to seafront. |
| M4 | 1 1+ | 1 water thickener | 6.5 | General purpose with moderate exposure. |
The water thickener referred to in this table is methyl cellulose.