Painted bricks- what to do?

[mh12]

Dear All.
Attaching pictures of garden wall which is partially painted. Not entirely sure if the paints are breathable or not.
The same is true for the cellar walls.
What is your advice with respect to whether the paint should be removed for longevity/health of the bricks i.e. to allow breathability if indeed the paint is non-breathable type.
Does the paint have to removed across the while exposed bit of the brick or just the mortar joints to allow breathability?
I have tried to removed the paint with scrapers and knife but is proving a challenge. Stubborn paint.
Has anyone ventured this type of task previously? Thanks in advance.

 

[Bash_Bash]

My brother has a similar issue and is considering using a jet wash…

 

[a twig]

Hiring a contractor with a DOFF machine is usually your best best.

Failing that you are into various chemical strippers - peel away etc

 

[Matt Green]

A needle gun might get you quite a long way- be careful if the bricks are soft though.

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[Stevers]

Caustic soda at a sensible dilution (you'll need eye and skin protection), followed by a pressure wash.

I used it to finish taking the paint of a stone fireplace surround, though without the pressure wash.

 

[HMOman]

steam clean is probably best

 

[mh12]

Thank you all for the suggestions. Stevers - any recommendations on regarding the caustic soda dilution ratio? How long does one leave the solution on the brick face before scraping the paint away?

HMOman stean clean- as in using the steamers used for taking old wall paper off?

On a general note how does one determine whether the paint on the bricks is compatible with the bricks/breathable? Reckon paint is fairly old and have no idea what the make of the paint is etc.

 

[Stevers]

any recommendations on regarding the caustic soda dilution ratio?

I used approximately 5ml heaped spoon / litre of warm water - add the powder to the water slowly stirring steadily. Never add water to the powder!

It's not an expensive option, and it didn't take long to work it's magic. It might work best with oil paints, but worth a try on a trial patch of whatever is on your bricks. There's a risk of it causing salting, but my fireplace surround already had that issue, and no salting now it's dried out.

This is probably the thread that inspired me to give it a go. 5% seems to be the sweet spot, and I suspect mine would hae been a bit weaker than that.

Experimenting with caustic soda (sodium hydroxide) paint stripping

Hi – I have been doing a little experimenting with a home brew paint stripper made from a 10% mixture of sodium hydroxide (a.k.a. lye, caustic soda) and water. Basically 1 gallon of water and 1 pound of lye. To the 10% solution I added a bit of corn starch and mixed that in until the...

www.practicalmachinist.com

 

[Kearn]

Send some samples of your paints to Restorative Techniques in Bristol. For the price of your postage they’ll analyse them in the lab and tell you what you’re dealing with and therefore what softener will work. Doesn’t look severe so I’d try a steam wash after softening, before spending tons on DOFF/ThermaTech ( effectively same product, one made by Stonehealth/other RT).

However, I’d bet the cellar pics are lime wash from the appearance and way it’s fading. Plastic paint will bubble/delaminate. If so, no need to do anything, it’s the ideal covering and you can make your own for peanuts and top up what’s there.

The outside pics aren’t screaming acrylic modern much either honestly.

Wet a finger, press it on and see what happens. Limewash/distemper will absorb the moisture and darken, plastic paints won’t.

If you have limewash on there, the above systems won’t really get it off either.

 

[stuart45]

A needle gun might get you quite a long way- be careful if the bricks are soft though.

Hilti TE 300-AVR + TE 106/TE 300 NA Breaker and needle adapter - HSS Hire

Hilti TE 300-AVR + TE 106/TE 300 NA Breaker and needle adapter. Check live stock availability today at HSS.com or visit us in over 300 branches

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I've used a needle gun on a few jobs, getting paint off stone walls. It's really good at doing the job, but the masonry needs to be really hard. The majority of bricks wouldn't take it. You need ear protection as well. The air guns are much lighter to use, that Hilti starts to get heavy at the end of the day.
This was the last job I used one on. The stone was mainly Chert, but there were a couple of small Blue Lias ones in which got wrecked, as did a brick. It virtually raked all the joints out for me at the same time ready for a repoint. Really good for cleaning old mixer drums out.