3 Tips for Preventing Cracks in Your New Pattern Pavers
Laying pattern imprinted pavers is a great way to bring life to a drab grey driveway. However, due to the intricacy of the designs on most pattern pavers, any cracks are likely to be much more noticeable than on standard concrete.
All concrete pavers require regular maintenance to prevent cracking, but you can help prevent cracks in your new driveway before the first slab is laid. Read on for three tips for buying and installing pattern pavers to make them less likely to crack.
1. Choose Colour Surface Hardener, Not Integrally Coloured Concrete
Most paving contractors will offer their customers a choice between colour surface hardener (CSH) or integrally coloured concrete.
CSH is a mixture that is applied to the surface of grey concrete to give it the desired colour. Integrally coloured concrete features the desired colour throughout the entire slab.
While integrally coloured concrete may sound attractive, it has half the strength of concrete that has been treated with CSH, leaving it more vulnerable to cracking.
2. Ensure Adequate Movement Joint Spacing
Good concreters will always install movement joints between slabs to allow for the normal contraction and expansion of concrete. This prevents tensile stresses from developing, which can cause pavers to crack.
According to the Portland Cement Association, joints should be placed at distances equal to between 24 and 30 times the thickness of each slab. For example, if slabs are 100mm thick, movement joints should be placed between 2.4m and 3.0m apart.
To ensure that your paving contractor is following these guidelines, ask for a copy of the proposed project design before the first slab is laid.
3. Don't Have Your Pavers Installed During Summer
Movement joints should be installed as soon as practicable, usually within 24 hours. This is because joints are more effective against cracking when they are cut before the concrete has completely hardened.
However, for each 10°C increase in temperature, the time it takes for concrete to harden halves. During summer, Australian temperatures can soar to over 45°C, and concrete mixtures can set in less than an hour.
This reduces the chance that movement joints will be installed within the desired timeframe, leaving your freshly laid concrete exposed to cracking from day one.
All concrete pavers are vulnerable to cracking, but cracks are much more likely to be noticeable on pattern imprinted concrete than on standard concrete. By following these tips, you can give your freshly laid concrete driveway the best chance of staying intact for years to come.