What is happening to my bricks?

[sparky24]

Hi all,
I have a problem with a few bricks on an internal chimney breast wall. There appears to be what can only be described as something resembling white cotton wool growing on the bricks. when touched it just crumbles away but comes back after a period of time.
Can anyone tell me what it is and how to get rid of it.

Thanks Sparky24

 

[2scoops0406]

It's called efflouresence, caused by water penetrating the bricks and causing salts within either the bricks or mortar to be deposited on the surface. First you need to find the source of the water penetration, once that is dealt with, simply brush it off, and repeat when necessary, it will eventually go away, but only after you've fixed the damp problem.

 

[Static]

Cotton wool? where is this (loft/lounge)? how big is the growth?
Post some photos if possible, it could be fungal in nature.. or if its like salt then might be efflouresence as eddie says

 

[^woody^]

Is the chinmey in use?

It may be caused either by rain getting in, condensation in an unventilated flue, or the flue gases.

 

[sparky24]

Thanks for your help. I cant post any pictures as i have got rid of it at the moment but it will come back again. The house is not a new build, it is about 50 years old.

The chimney is between the kitchen and living room so it is not an outside wall and the "efflouresence" is only occuring just above the skirting board in an isolated patch about 1 square foot. The fireplace houses a gas fire without back boiler that is hardly ever used so it is possible that rain could be coming down the chimney but i cant see any evidence.
The wall was originally wallpapered but i want to paint it when i get rid of the problem.
I searched for efflouresence on google and found a website that said to use masonary primer to seal it. What are your thoughts on this?

 

[Symo]

Probably the flashing around your chimney where it meets your roof or the pointing around the "pots". Rain gets in, runs inside chimney, pools at the bottom and causes the damp patch.

Symo

 

[^woody^]

Although it is possible that rain is coming down the chimney right to the bottom and causing dampness near the skirting, it is towards the end of the list of possible causes.

I would look at dampness coming up or condensation first