Blackfriar Interior Seal Damp


Don’t let damp patches spoil your interior decoration, protect it with Blackfriar Interior Seal Damp.

Bulk Buy

£15.37 tax excl.

£18.44   tax incl.

Product Description

Don’t let damp patches spoil your interior decoration, protect it with Blackfriar Interior Seal Damp. It’s excellent for use prior to decorating as it can be painted or papered over, and is suitable for surfaces such as plaster, brick and cement, but is not recommended for wood.


  • Protect interiors from damp
  • Use on plaster, brick & cement
  • Ideal for pre-decoration

It is your responsibility to read the Product Data Sheets (available below) before you place an order and prior to application of the product. The content of this website is our best recommendation and is not advice. Coverage rates quoted are approximate, you agree that coverage depends on the condition of the substrate, surface absorption, texture and application method. We ALWAYS recommend a trial area is coated to ensure the product meets your requirements before use.

Technical Data

Typical Coverage (per coat)12m² per litre
Touch Dry2-4 Hours
ApplicationBrush, Roller
The figures stated above are approximate. Please ensure you refer to all datasheets for full application information.


Customer agrees that before placing an Order, Customer has read and understood the most up to date Product Data Sheet for the Product. Where we have access to the Product Data Sheet from the manufacturer, we will either provide a copy on request, or include a link to the Product Data Sheet available on the manufacturer’s website. Customer further agrees that we have no liability for any errors or omissions contained within the Product Data Sheets. For more information, please see our Terms & Conditions of Sale.


questions Stephen  on 15/02/2019

Hi, Can this be used as a top layer on an already painted wall?


Blackfriar Interior Seal Damp should be applied to bare plaster. If applied to a painted wall which is damp the paint may blister up behind the Seal Damp. It will be best to sand off the paint in the damp areas before applying the Seal Damp.

questions Gary foxcroft on 13/11/2018

Can this be used on an interior bathroom with real bricks & stone.the bricks are fine but the stone is flaking away Badly . will this product prevent that.


Blackfriar Interior Seal Damp will darken the colour of the stone, if this is OK then brush the stone well to remove as much dust as possible, thin the first coat of the Blackfriar Interior Seal Damp with white spirit to act as a sealer coat, followed by 2 further coats.

If a clear non-darkening product would be preferred then the Blackfriar Quick Drying Varnish would probably be OK depending just how friable the stone surface is, brush off the loose material as above. Thin the first coat of the varnish with water then 2 full coats.

questions Lesley Callaghan on 29/07/2017
Question: Can the black friars paint be used on already damp walls that have penetrated ordinary emulsion on new plaster.

Blackfriar do say to apply the Interior Seal Damp to bare plaster however you can lightly sand the paint finish with the damp marks showing then apply the sealer. 2 coats can be applied then overcoated with your emulsion paint.

This product will only hold back minor damp problems, if there is a constant damp issue this should be resolved.

Question about the product

* Required fields

The question has been correctly sent

Free delivery

On orders over
£75.00 + VAT

Low trade prices

Our best trade prices on everything!

Technical Advice

Fast FREE Technical Advice for Products & Projects

Click & collect

Order and collect from
our Leeds based trade store.
silent-exothermic unable