white residue on engineering bricks

[cbrann]

I Cleaned some tyrolean render off some engineering bricks and its left a residue on the brick, I have used brick acid, thinners, turps, wire brushes and nothing moves the residue, has anyone had any experiences like this.

 

[footprints]

Any chance it might just be efflorescence from soaking the bricks?

https://www.constructionspecifier.com/why-red-brick-turns-white-understanding-efflorescence/4/

 

[cbrann]

Hi footprints, no I am quite sure it's not, it was there when I took the top layer off with a scraper, then alot of hard work mainly with stainless steel scourers.

 

[footprints]

A good power wash? Not one of the Lidl cheepies but a pro one hired perhaps.

 

[cbrann]

No tried that it took the morter out but nothing else

 

[Dannyboyski]

I have done lot of cleaning bricks on our renovation over the past year, and also a lot of paint removal. The Torik steam cleaner we are using on our house would have that off I think. Be careful with pressure washers, they have the capacity to eat bricks. granted you have engineering bricks that should be a lot harder than what ive been working on.

Other things you could try in a small area - sugar soap - this cleans soot off bricks better than anything else Ive tried.

caustic soda (be careful, makes brick acid look like a relatively safe solution!) I mix it with wallpaper paste and water, it's heavily alkaline, so just like acids work, alkali's substances can do the same job.

TSP - Trisodium phosphate, didn't work for me, but inexpensive and worth a punt.

Bicarbonate of soda blasting. (supposed to be quite effective)

Be aware brick acid is available in various strengths the strongest ive found is 36% I think, anyway this is a different beast to the 10% stuff.

really depends what the tyrolean is made of, if its cement based, the strongest brick acid you can get should get it off. you'll need to invest in a decent acid sprayer and where suitable PPE for all of the above.

Good luck fella.

Db

 

[ted456]

Your pics dont show any Tyrolean only a thick coat of paint.
Thats not efflorescence mate its the resideu from the paint you scraped off.
Like footprints says a pro power washer is the best thing to try.But set the pressure just right for the face bricks.
If you try chemicals you'd have to beware of passing pedestrians.

 

[Dannyboyski]

I hadn't seen the 2nd set of photos when i posted earlier. Are you sure this is render and not just the remnants of paint?

my advice is to get a steam wallpaper stripper £20ish I think. steam the marks and if you can get any movement from them then steam is the correct way to go. the steam cleaners aka torik are very gentle because its 150c but low pressure so won't damage the bricks.

 

[martin hill]

Try a few bricks with a hot air gun. It looks like paint or a glue residue from under the tyrolean. As others have said be careful with pressure washer or blasting as it can damage the mortar and brick. Ended up myself having the front of my house meshed for the new rendering as it would of been too risky on the old brick.

 

[Nige F]

No tried that it took the morter out but nothing else

Just a thought - thin joints, taken out by washer. Really hard bricks etc. Could they be mathematical tiles ?