STOPGAP F77 is a solvent free two part epoxy resin system which cures to provide a waterproof surface membrane. STOPGAP F77 impedes the passage of residual construction moisture and rising damp from affecting subsequent floorcovering installations, therefore allowing early installation of floorcoverings in fast track building programmes.
STOPGAP F77 is pigmented black to allow the user to visually control coverage uniformity. It can be used to isolate residual construction moisture where relative humidity values are up to 98%.
It is essential that STOPGAP F77 is applied to a clean and absorbent substrate.Any surface contaminants such as surface hardeners, cement laitance etc., should be removed to produce a slightly textured surface.The surface strength of the substrate should be greater than 1.5 N/mm2 in accordance with BS 8204-6 Part 7.2. Power floated concrete should be mechanically prepared. New concrete or sand/cement screeds should be left for a minimum 7 days before surface preparation and application of the membrane.
For further guidance please refer to the F. Ball Subfloor Preparation Guide.
Rough, uneven or damaged concrete or sand/cement screeds must be smoothed/ repaired with STOPGAP 1200 PRO, STOPGAP 1500 AQUAPRO, STOPGAP GREEN BAG/114 or STOPGAP 460 EXTERIOR REPAIR. Joints between bays where continual movement of the base is not anticipated or small hollows may be filled with STOPGAP F77 mixed with clean dry sand and allowed to fully cure before applying the membrane.
Care must be taken to minimise the occurrence of pinholes in the underlayment when pre-smoothing.
It is essential that hygrometer readings in accordance with Appendix A of BS 8203 (Installation of resilient floor coverings) and BS 5325 (Installation of textile floor coverings) are taken and recorded prior to commencing the installation.
For details on other subfloors, contact our Technical Service Department.