DIY advice on sealing internal brick walls

slushing priming a wall before wall coating

We often get asked questions and advice, although we’re not strictly a free advice line, we do actually respond to EVERY email we get, whether it is relevant or not and here is an email from someone wanting brick wall sealing advice.

Robert emailed us with a question about discovering a brick internal wall whilst decorating and renovating , and thought it would be a nice feature in his room, however he had concerns over the often flaky and powdery nature of some bricks.

This is especially true if the bricks were covered up with plaster for a reason, and upon removing them, the brick acts in a way that almost screams at you “Cover me back up!”.

The brick can flake and turn to powder, the pointing can drop out, and basically the wall cannot be left seriously in the state it is in.

DIY advice

There are various ways that you can seal an internal brick wall which often make nice decorative features, especially with many contemporary “farmhouse style” fitted kitchen many houses yearn for nowadays but what is the correct way to seal the wall?


porous bricks let damp into the wall

Porous bricks will let damp into the wall


Our reader suggests one, the team here suggest one example, do YOU have any suggestions?

The following message is from a real, genuine user of the site, AND NOTĀ  an article the editor made up! Thank you.

Message begins……..

Name: Robert **********

Address; *****************

Enquirer Reason:
Hi there,
I’m currently renovating a bedroom, and after removing some very old
plaster back to the brickwork, I noticed the brick feature looked rather good. Obviously, if I left the bricks as they are now, I will be forever plagued with brick dust and crap covering my carpet, so I need to seal it.

However, I can’t find any good advice (for the UK) of what to use to do about this. I don’t want the walls to be particularly glossy and shiny either. I have heard that turps mixed with linseed oil will seal the walls, but how effectively?

What would you recommend?

Many thanks

This mail is sent via Enquiry Form on Never Paint Again.

Hi Robert and thank you ever so much for asking us a question.

We don’t generally run a free DIY advice service (!!!) (LOL!) however i dont mind the email either, its good to hear that our website is widely read by the public.

I will post this on our blog, with my reply, and your details removed, to see if anyone else has any suggestions.

As a rule, and in my experience, this is what you should do………

The easy way to seal a brick wall

1. Make sure any mortar joints (pointing) are not missing or loose and if so, repair them with some new mortar. If the wall is very old it may have lime mortar, but you can get a dye called an “admix” or “febmix” which can add colour to mortar and this can be bought at any branch of Wickes or B and Q, in the building supplies section.

2. Once the above is done, lightly brush the wall with a soft broom head or old emulsion brush to get rid of dust.

3. Take some PVA, commonly known as UnibondĀ®, and add about the equivalent of half a coffee mug to water and mix it in very thoroughly. The water should now look like milk.

unibond PVA

4. Lightly brush the solution onto the wall, starting at the top and working down and remember to wear washing up rubber gloves whilst doing it. Make sure the ground is covered with something that will soak up the unibond as it dries like a glue.

5. Allow to dry (it will go cloudy at first), and then make sure no bits have been missed.

6. The next day you should have a nice wall, free of dust. Note there WILL BE a slight sheen on it, this is the only way to seal an interior wall, however as far as your suggestion , I have never used that method so i can’t comment, however using turps and linseed oil would probably make the room stink for weeks, whereas this method will not..!.

Good luck with your project

Kind regards

The never paint again team

Disclaimer: “Unibond” is a registered trade mark, owned by Henkel, and is only used here as a product review. Thank you

PS: If you need advice about sealing, damp proofing or weatherproofing EXTERNAL walls, go right up to the top of this page and use the menu links to find the info you need.

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