Damp, Salts, Plaster, Condensation...the nightmare goes on

[activist3]

Hello All,
Having an absolute nightmare! Over several years we have had black mould grow on the walls in certain areas in the house and we had an injected damp course put in to try and help with the problem. However this has not done anything. I have cleaned off the mould in all the rooms but it is an ongoing issue.
However the worst problem is downstairs. When we had the damp course done we had the wall hacked, damp course and then skimmed. We painted the wall and after a few weeks salt came through the walls and the paint bubbled off. I have left this like that for several years but recently went to redecorate. I scraped off the bubbled paint and salts and have repainted in one of the corners but the salt has come through again and bubbled through the paint. In the other corner of the room we have hacked off the plaster and replastered but the plaster isnt drying very well and is also cracking.

Can anyone help? I know nothing about diy, painting or building but am really worried about what to do as hoping to put the house on the market soon.

 

[mointainwalker]

Do a search on 'black mould" , "salts" and "condensation" and you will have a couple of days reading that should addresss all aspects of your problem.

 

[Plasterer1968]

I have remedied walls as you descibed with complete customer satisfaction. Where I have not has been due I think to how the customer carried out the initial important process.

Ok, if you can't plaster this may not please you. But read on!

Wickes sell a 'anti-damp bitumen' £14.00ish paint. You need to completely remove the plaster back to brick from the affect area.
Paint the bitumen over the brickwork.
Do not leave any micro holes of the brick background to show!!
I would perhaps paint this once dry and again to be sure.

On the last coat you will need to blind the the wet paint with Carlite Browning or Bonding coat. Literally that means throw small amounts against it to provide a key.

Once done a coat of background plaster (Browning or Bonding) and then skim. You can use render (sand and cement with waterproofer - 5L is £3.49 from Wickes-added for 100% peace of mind)

 

[joe-90]

Sorting out the damp issue would make more sense.

 

[Plasterer1968]

Sorting out the damp issue would make more sense.

You may not source the damp. The way I have advised is the same as a cellar but in a smaller degree.

FWIW I have carried this method out with SBR as well as Wickes cheaper solution on 2ft thick cottage walls without cavities. Still no damp after 5 years.

If you get a specialist in with plans (£150+) it will tell you to cut the wall back 1m high and apply render and skim.

Joe: This is how you would be advised to carry out the issue in my experience of many years.