Product focus: Stopgap F77

A closer look at F. Ball’s high-performance waterproof surface membrane.

What is it?

Stopgap F77 is a solvent-free, two-part epoxy resin liquid waterproof surface membrane which cures to provide a barrier against excess subfloor moisture.

It impedes the passage of residual construction moisture and rising damp from affecting subsequent floorcovering installations where subfloor moisture levels are up to 98% relative humidity (RH).

Where is it used?

Where subfloor RH levels are above 75% (or 65% where wood floorcoverings will be installed), creating the potential for moisture to attack adhesives and floorcoverings, resulting in floor failure.

It is suitable for installations that are part of refurbishments in older buildings and a structural damp-proof course is not in place, as well as in new-build applications where subfloors have not had time to dry out naturally.

What’s different about it?

The product is colour pigmented to help gauge coverage uniformity.

Something you might not know about the product:

It can be applied directly over screeds with underfloor heating systems incorporated where moisture readings are up to 90% RH.

For more information about Stopgap F77, visit the F. Ball website.