Stopgap F78


STOPGAP F78 is a solvent free, one component, ready to use system which dries rapidly to provide a waterproof surface membrane. STOPGAP F78 impedes the passage of residual construction moisture from affecting subsequent floor covering installations, therefore allowing early installation of floorcoverings in fast track building programmes.

STOPGAP F78 must be applied in two coats and can be used to isolate residual construction moisture where relative humidity values are up to 95%. It is pigmented blue to allow the user to visually control coverage uniformity.

It is essential that STOPGAP F78 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. Bases must contain a structural damp proof membrane. Rough, uneven or damaged concrete or sand/cement screeds must be smoothed/ repaired with STOPGAP 1200 PRO, STOPGAP GREEN BAG/114or STOPGAP 460 EXTERIOR REPAIR.

Joints between bays where continual movement of the base is not anticipated or small hollows may be filled with an epoxy based material such as 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 floorcoverings) are taken and recorded prior to commencing the installation. For further guidance please refer to the F. Ball Subfloor Preparation Guide.

General information



Uniclass 2015

Pr_35_31_68_47 Liquid tanking resinsPrimary


M42/150 Composition block flooring

M42/20 Composition block flooring

M42/30 Concrete/ Screed substrates

M50/10 Resilient floor tiling

M50/110 Resilient floor tiling

M50/130 Carpet tiling

M50/15 Carpet tiling

M50/150 Sheeting

M50/155 PVC sheet flooring in special wet areas

M50/170 Carpeting

M50/20 Sheeting

M50/25 Carpeting

M51/110 Carpeting

Specification data - Liquid tanking resins

Product Reference

Stopgap F78

Product Options

Technical properties:

  • Colour: Blue.
  • Cure time at 20°C: 1 hour.

Digital objects

Platform Compatible Version Certified to

Revit 2017




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