MANY problems which occur with floorcoverings are because of moisture in the subfloor, so it’s essential the final floorcovering is protected from the passage of moisture from below.
A damp-proof membrane will protect against residual construction moisture, and continual rising vapour from the earth, and is required where a structural damp-proof membrane isn’t present or is ineffective.
This is likely to be the case in refurbishment projects involving buildings constructed before 1970, where the installation of an effective structural damp-proof membrane wasn’t a requirement of the Building Regulations at that time.
Now BAL says it’s resolved this problem for tilers with the introduction of what it describes as new high performance, multipurpose one-coat DPM and primer, creating a barrier against damp and moisture on floors and walls with up to 98% relative humidity (RH).
Reportedly resistant to water, chemicals, grease and pollutants, BAL DPM can be used internally or externally as a DPM, primer, water-proofer or residual moisture vapour suppressant.
New BAL DPM can be used on sand:cement screeds, power-floated concrete and exiting tiles on walls and floor for basements below the water table. What’s more, it can also be used on anhydrite screeds with up to 87% RH.