fizzy walls
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Discussion

qube_TA

Original Poster:

8,405 posts

261 months

Monday 5th October 2009
quotequote all
Hi,

I've a problem on several walls where the salt in the brick comes through and causes the plaster the bubble & fall off.

Anyone recommend something that can seal it and stop it coming though?


TooLateForAName

4,888 posts

200 months

Tuesday 6th October 2009
quotequote all
You need to sort out whatever is causing the damp.

qube_TA

Original Poster:

8,405 posts

261 months

Tuesday 6th October 2009
quotequote all
TooLateForAName said:
You need to sort out whatever is causing the damp.
It's not damp it's effervescence, walls are bone dry.




b2hbm

1,300 posts

238 months

Tuesday 6th October 2009
quotequote all
We had that problem from one of the existing house walls when we built an extension and even after everything had dried out it still came through and blew off the top layers & paint. In the end I stripped off all the plaster down to the brickwork and rendered it with mortar and an additive to stop dampness coming through. Can't recall what it was called but we bought it from Wickes on the advice of a local builder.

A bit drastic but nothing I could find would seal it otherwise.

toomuchbeer

877 posts

224 months

Tuesday 6th October 2009
quotequote all

TooLateForAName

4,888 posts

200 months

Tuesday 6th October 2009
quotequote all
qube_TA said:
TooLateForAName said:
You need to sort out whatever is causing the damp.
It's not damp it's effervescence, walls are bone dry.
If the walls were bone dry you wouldn't have any moisture to evaporate leaving salt deposits.

//pedant mode : efflorescence

qube_TA

Original Poster:

8,405 posts

261 months

Tuesday 6th October 2009
quotequote all
TooLateForAName said:
qube_TA said:
TooLateForAName said:
You need to sort out whatever is causing the damp.
It's not damp it's effervescence, walls are bone dry.
If the walls were bone dry you wouldn't have any moisture to evaporate leaving salt deposits.

//pedant mode : efflorescence
But it's happening on internal walls upstairs, there's nothing that can cause it to be damp and it's only in small patches, if I go in the loft there's patches there too, looks like cotton wool.






Steve_D

13,799 posts

274 months

Tuesday 6th October 2009
quotequote all
qube_TA said:
TooLateForAName said:
qube_TA said:
TooLateForAName said:
You need to sort out whatever is causing the damp.
It's not damp it's effervescence, walls are bone dry.
If the walls were bone dry you wouldn't have any moisture to evaporate leaving salt deposits.

//pedant mode : efflorescence
But it's happening on internal walls upstairs, there's nothing that can cause it to be damp and it's only in small patches, if I go in the loft there's patches there too, looks like cotton wool.
Sounds like your wall ties are bridged.

Steve

mycroft

1,545 posts

263 months

Tuesday 6th October 2009
quotequote all
My understanding of this is that the walls are not damp , so there is nothing you can do to seal it .
The salts are not coming through or into the wall they are already present within the wall , the method with this type of problem is to keep cleaning the wall down but don't wash it , just wipe with a dry cloth and rub the surface down with fine sand paper . Any salts in the wall tend to act as a sponge and soak moister out of the atmosphere so expect it to get worse in wet close weather .
If the skimming separates from the base-coat you will just need to re-skim , carlite plasters tend to act worse in situations like this , renovating base-coats are designed to prevent this type of problem as they hold the salts back .
Hope that makes sense , I'm a builder my IT skills are cr@p .

Wings

5,892 posts

231 months

Tuesday 6th October 2009
quotequote all
It could be due to the type of plaster used on the walls. I have a similar problem with a rented property, and following inspection of the same, the only remedy is to hack off all the plaster, and re plaster using the correct type of plaster.

http://www.sustainablebuildingresource.co.uk/build...