brickwork.

[plasticpigeon]

Hello people. Can anyone offer me advice please. I have been doing a bit of brickwork here and there on my house. Mainly at the back where it has subsided and the walls are a mess. The bricks on my house, some kind red bricks with lots of palm prints on them, are extremely porous. Even if I use very sloppy mortar, I can hardly position the brick before it has had all the water sucked out of it and it is very hard to work with. I have used some very wet bricks that were sat outside after a neighbour demolished their outbuildings. These were much easier to work with, but take an age to dry out, and then they do dry they have a whitish surface coating (old lime??) which is difficult to brush off. When the bricks are wet this disappears. What is the normal way of dealing with this, is there some magic wetness of brick I should be aiming for??? Thanks.

 

[Feltwell]

I've always found damp bricks to be much easier to work with. Your whitish surface coating sounds like efflorescence to me - does it look like this?

http://www.ibstock.com/pdfs/technical-support/TIS-02-efflorescence.pdf

It's totally harmless and will weather off in time.

 

[plasticpigeon]

Ah yes, I forgot about efflorescence. I think some of it might be lime dust where it is just slightly discoloured, probably because I was washing the bricks in a bucket of water that got progressively dirtier the more bricks I washed! On some bricks it definitely looks like the picture too, thanks!

 

[stuart45]

In theory porous bricks should be slightly damp when laid, but in practice on site when are laid as they come, wet or dry. Salts are usually much common in newer bricks than old ones that have weathered. If bricks are really wet when laid there is more chance of mortar staining on the face, and also of salts coming to the surface.
When cement mortar is used calcium oxide is a by product of the reaction which can get washed out onto the face and absorb CO2 to form a hard lime stain which is harder to remove.
Depends on what mix of mortar you are using, but plaz in it makes it much easier to use.

 

[Gervase]

A quick dunk and wiggle in a bucket of water just before the bricks are buttered is the best way - it get the surface wet enough to kill the initial suction, but doesn't saturate them.

 

[Feltwell]

Ah yes, I forgot about efflorescence. I think some of it might be lime dust where it is just slightly discoloured, probably because I was washing the bricks in a bucket of water that got progressively dirtier the more bricks I washed! On some bricks it definitely looks like the picture too, thanks!

I found a cheap pressure washer by far the easiest way to clean loose bricks - I had 3000 to clean, and they had a fair bit of industrial grime on them. I just stood them a dozen at a time on an old pallet and gave them a very quick blast - got the worst of the muck off and no significant efflorescence problems resulted.

Possibly one of the more boring jobs ever though!

 

[biffvernon]

Even if I use very sloppy mortar,

Lime mortar?

 

[plasticpigeon]

Yes I'm using lime!!! It may not be sloppy compared to what some people use, but enough to position the brick. I have followed the advice of Gervase and have given these evil bricks a quick dunk in water before using them. This has made things much easier!