F Ball - Stopgap F78 High Performance Waterproof Surface Membrane

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F Ball - Stopgap F78
  • Available for Next Day Delivery
  • FREE Delivery when you spend over £125

F Ball - Stopgap F78 High Performance Waterproof Surface Membrane 

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 floorcovering 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.

Technical Information:

  • Appearance: 6kg Liquid container
  • Colour: Blue
  • Cure Time: Approximately 15-30 minutes for the first coat at a temperature of 20°C, for the second coat allow 30 minutes
  • Available in: 12kg, 6kg and 18kg capacity



Applications up to 95% RH – 3.3m2 /kg as a two coat application. Note: The coverage rate refers to a smooth, clean surface. A textured or highly absorbent surface profile will reduce the coverage rate.

6kg = approximately 20m2 up to 95% RH
12kg  = approximately 40m2 up to 95% RH
18kg = approximately 60m2 up to 95% RH

For any areas under question please consult the F Ball Technical team.

Curing Time:

This greatly depends on temperature. At an ambient temperature of 20°C allow 15-30 minutes for the first coat to become touch dry then apply the second coat. Allow 30 minutes for the second coat to cure.


Do not use STOPGAP P131 to prime STOPGAP F78. Joints designed to allow movement of the subfloor must not be bridged with STOPGAP F78 waterproof surface membrane. These joints must be sealed with a suitable impervious flexible jointing compound after the application of the membrane. Do not use over synthetic anhydrite or other gypsum/sulphate based subfloors. Not suitable for use on subfloors with underfloor heating.


Paint roller. Wash tools with warm water immediately after use


Store between 5ºC and 30ºC.

Shelf Life:

12 months in unopened containers stored under good conditions

Delivery Information

We aim to dispatch all orders within 2 working day of receipt. Occasionally public holidays, weekends, weather events, or extremely busy periods may result in extended delivery times. In these circumstances, we will endeavour to communicate with you about the delay and resolve and resulting issues.

Please note that we do not make delivery date promises, however:

- Orders placed before 1pm on a weekday will be processed the same day.

- Orders placed after 1pm on a weekday will be processed the following morning. 

- Orders placed after 1pm on Thursday will be processed and dispatched the following day and out for delivery the following Monday (if Next Day Delivery is selected).

- Orders placed after 1pm on Fridays will be processed and dispatched on the following Monday.

For more information about our Shipping & Delivery services click HERE


UK Mainland Delivery Options:


Free Delivery: Applicable for orders of £125 excl. VAT and above
(Monday – Friday, excluding public holidays)


Collect From Store: 41 Markfield Road, London N15 4QA
(Monday – Friday, 9am–5pm excluding public holidays)


Standard Delivery: 3-5 Working Days
(Monday – Friday, excluding public holidays)


Express Delivery: Next Working Day
(Monday – Friday, excluding public holidays)

Out Of Zone Delivery Surcharges:

Isle of Wight

£12.50 per item (3-5 Working Days)

Isles of Scilly

£12.50 per item (3-5 Working Days)

Northern Ireland

£25.00 per item (3-5 Working Days)

Western Isles

£25.00 per item (3-5 Working Days)

Shetland Isles

£30.00 per item (3-5 Working Days)


£30.00 per item (3-5 Working Days)

Isle Of Man

£30.00 per item (3-5 Working Days)

Channel Islands

£30.00 per item

Republic of Ireland

Not Available


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