Cleaning brick wall ?salts ?limescale

jonnydeppiwish!

Has anyone had experience of cleaning such a stain from an older wall? I was going to try and pick up some hydrochloric acid in the morning and leave it to work for 10 mins but a bit reticent in case I damage the bricks.

I’m assuming it’s been caused by a leaking gutter in the past, or even where a plant may have been prior to the tarmac being laid.

Will test it first of course!

grumbler

This is called 'efflorescence'

https://www.google.com/search?&q=efflorescence

Eldi_Dos

Is there a shower in that corner behind the wall?

jonnydeppiwish!

Eldi_Dos said:

Is there a shower in that corner behind the wall?

No, just a toilet. There’s no pipe work either above 3 courses of brick above the damp course.

jonnydeppiwish!

Just to add, it is a SW facing corner with the prevailing wind and rain.

stuart45

Try brushing it off first. If you ever use acid on brickwork, make sure you soak the wall first, so the acid works on the surface and doesn't soak into the wall. 
Those bricks look like LBC Tudors, which I've noticed seem to suffer from this problem when soaked.

Annemos

I am noticing this much more this year. 

It has always been visible on garden walls. But now I am seeing it on actual houses and flats. Ones that have been standing for about 30 or 40 years are suddenly showing this effect. And folks who had extensions built above garages etc. 

I have this in a small area where I cleaned the shady side path of moss and accidentally splashed Jeyes cleaner! (Lethal stuff. It worked great on the moss, but I was not happy to see the salts on the wall. The Jeyes must have activated some minerals in the bricks? LBC Cotswald.)

The salts I can see are incredibly hard. The only way I can describe it....is that it reminds me if what I would expect to see in limestone caves. 

Brushing does not get rid of mine.

FreeBear

stuart45 said: Try brushing it off first. If you ever use acid on brickwork, make sure you soak the wall first, so the acid works on the surface and doesn't soak into the wall.

And dilute the acid first.

Always add acid to cold water, never ever add water to acid. Wear suitable waterproof clothing, marigold type rubber gloves and a face shield (better protection than just goggles). If you must use full strength hydrochloric acid, don't breath in the fumes.

Also worth having a bucket of clean cold water on hand to douse yourself if there is a spill.

stuart45

Annemos said:

The salts I can see are incredibly hard. The only way I can describe it....is that it reminds me if what I would expect to see in limestone caves. 

Brushing does not get rid of mine.

it could be lime run off. There are free limes in cement mortar which can be washed to the surface and absorb carbon dioxide to form a hard calcium carbonate.

jonnydeppiwish!

Thanks for all the responses.

Brushing has no effect. Wire brushing doesn’t seem to either but I’m not pressing too hard.

I work with HCL on a daily basis so should be okay safety wise thumbs up. 

The Silka Brick cleaner doesn’t seem up to much. Tried a 1:3 then 1:2.  Will give it a few try later today as well.

B0bbyEwing

stuart45 said:

Those bricks look like LBC Tudors, which I've noticed seem to suffer from this problem when soaked.

@stuart45 I'm going to gamble (in all honesty I'm just being different) and say they look like LBC Chiltern's  

Either way, I don't think I've ever found packs of bricks that attract spiders more than LBC bricks. 

And when you've a phobia of spider's, they're not my favourite brick!!


Just saved the photo & zoomed in. I think you're right actually. Unless I've got it back to front the Tudor's have moon crater imprints on them whereas the Chiltern's have pin-pricks.