Acid Washing Bricks
Normally new brickwork would be cleaned down with a sulphuric acid mix, a week or so after completion. But we had to wait for our rendering & mouldings to be complete first - well that was the advice we received from the company that provided the mouldings (as the rendering process would make a mess over a newly cleaned wall).
But to our dismay, the mouldings company changed their mind -- after the mouldings were up, they said we should have washed the bricks first, as the acid would damage the mouldings. So we had to buy A$500 of a sealing product to protect our mouldings (it's a suspension of silicone in a solvent, so it doesn't change the appearance after application). It work very well in the end.
The current fashion amongst brick-cleaners is to use a high-pressure spray of sulphuric acid, diluted 1 part acid to 8 parts water. But this would pose another risk to our mouldings, and it can remove too much mortar.
We opted to have the acid applied with a brush (1 part acid to 4 parts water). Then it was left for about 30 minutes, and washed down with a low-pressure spray. We were thrilled with the reuslt, as we had grown used to looking at un-washed walls for about 6 months!
But to our dismay, the mouldings company changed their mind -- after the mouldings were up, they said we should have washed the bricks first, as the acid would damage the mouldings. So we had to buy A$500 of a sealing product to protect our mouldings (it's a suspension of silicone in a solvent, so it doesn't change the appearance after application). It work very well in the end.
The current fashion amongst brick-cleaners is to use a high-pressure spray of sulphuric acid, diluted 1 part acid to 8 parts water. But this would pose another risk to our mouldings, and it can remove too much mortar.
We opted to have the acid applied with a brush (1 part acid to 4 parts water). Then it was left for about 30 minutes, and washed down with a low-pressure spray. We were thrilled with the reuslt, as we had grown used to looking at un-washed walls for about 6 months!
posted by Steve at Sunday, October 29, 2006
3 Comments:
Interesting to hear about the current methods. I was a brick mason's laborer during high school (fifteen years ago) and I used to do the washing myself. The mix sounds right, but we normally just dipped a scrub brush into a bucket, scrubbed the mix onto the wall, then rubbed over that wet wall with another brick to knock off the bits of mortar and to clean up the joints. Most brick has a sanded finish on the face that helps during cleanup as well.
Freshly washed brickwork is a beautiful thing... I'm glad you guys are enjoying yours. The pictures look very nice.
Looks like some quality construction I'd say. Very nice to see.
Looks stunning.
Great shots !
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