F Ball – Stopgap F78 High Performance Waterproof Surface Membrane

£209.98£209.98 /item (incl. VAT)

  • Available for Next Day & Saturday Delivery
  • No Minimum Order
  • Order yours before 1pm for same-day dispatch


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.

Product Specifications & Key Features:

  • Appearance: 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 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.

  • 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

Additional information

Weight N/A
Size: No selection

12 kg, 18 kg

Appearance: No selection

Plastic Container

Brand: No selection


Delivery Information

We aim to dispatch all orders within 1 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 1 pm on a weekday will be processed the same day.
  • Orders placed after 1 pm on a weekday will be processed the following morning.
  • Orders placed after 1 pm 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 1 pm on Fridays will be processed and dispatched on the following Monday.
  • Saturday Delivery – the cut-off day to receive an order on a Saturday of the same week is Thursday.

For more information about our Shipping, Delivery & Returns services click HERE

UK Mainland Delivery Options:

Free Collection from our London Store (See on the Map)
(Monday – Thursday: 9 am–5 pm; Friday: 9 am-1 pm excluding public holidays)
Location: 41 Markfield Road, London N15 4QA
£9.50 Standard Delivery: 3-5 Working Days
Applicable for all orders (apart from Pipe Covers & Samples)
(Monday – Friday, 9 am–5 pm excluding public holidays)
£18.00 Express Delivery: Next Working Day
For orders placed before 1 pm on a weekday
(Monday – Friday, 9 am–5 pm excluding public holidays)
£12.50 Bulky Item Surcharge Fee
For orders containing heavy & bulky items (Selected Underlays only)
(Monday – Friday, 9 am–5 pm excluding public holidays)
£20.00 Long Item Surcharge Fee
For orders of long-length items (2700mm Metal Door Bars & Laminate Scotia Beadings)
(Monday – Friday, 9 am–5 pm excluding public holidays)
£65.00 Saturday Delivery
(Saturday only, 8 am-1 pm excluding public holidays)

Out-Of-Zone Locations

Unfortunately, due to courier restrictions, we do not deliver to the locations listed below:
– Isle of Wight, Isles of Scilly, Western Isles, Shetland Isles, Orkney, Isle Of Man, Channel Islands, Northern Ireland, Republic of Ireland

In addition, we do not deliver to any locations with the postcodes listed below:
– IV27, IV40 -> IV49, IV51 -> IV56
– KA27, KA28
– PA28, PA29, PA40 -> PA49, PA60 -> PA80
– PH39 -> PH44

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