According to the Building Services Authority, 85% of flooring failures are due to the presence of moisture in the concrete from hydro-static pressure or green concrete.
The BSA is inundated with countless claims of floors failing due to moisture. When this happens, you end up …
- Wasting your valuable time and money having to redo jobs and repairs …
- And annoying the customer wasting their time and money sorting out the floor …
This could be avoided by completing a simple moisture test on your concrete. A majority of floors are never moisture tested. This is a very quick and easy test to complete using a Moisture Meter from Con-Treat.
To conform to the Australian standard (AS1884‐2012), concrete must have a reading of no greater than 75% relative humidity.
As a general rule of thumb, concrete dries at approximately 20‐25mm per month in an average environment. An average slab of 100mm thick can take 4‐5 months of drying time before it will conform to Australian Standards.
Also, concrete is like a sponge and will continue to absorb water if present. If concrete is exposed to rain, locked up in a building or has a curing agent applied, this will further increase the drying time. Higher relative humidity will slow drying times even further too.
Hydro-static pressure should be a major concern for contractors as it comes from underneath the concrete and moves its way through the capillary voids in the matrix of the concrete.
Once a floor has been installed, it will draw any moisture present in the concrete to the surface and if there is no means of escape will react with, and break down the bond of the subsequent coating.
Hydro-static pressure can come from things such as a hidden spring running underground, high water tables or low lying flood land and is generally not noticeable without moisture testing.
Obviously waiting for the concrete to dry isn’t really an option due to the lengthy time delay. A Moisture Barrier needs to be applied so that you can fast-track the project and prevent future problems with any moisture. Always complete a moisture test on your concrete to avoid any hidden surprises.
* The above information is to be used as a guide only and Con-Treat accepts no responsibility for any consequence resulting from the advice contained herein or verbally.