Damp spots on wall

[robson127]

I had a damp proof course about 6 months ago.

Recentley ive noticed a couple of damp/wet spots on the wall about 2 foot from the ground.

What could these be?
Has the damp course failed or could they be existing damp leaving?

[acidburn110]

Could be any number of thing mate. We've had similar issues ourselves which folk on here have advised us about to great effect. Search my posts on here against my username - might answer some of your questions.

Is it an external wall and may i ask which method of plastering was used after the DPC was installed?

[robson127]

Could be any number of thing mate. We've had similar issues ourselves which folk on here have advised us about to great effect. Search my posts on here against my username - might answer some of your questions.

Is it an external wall and may i ask which method of plastering was used after the DPC was installed?

Hi

One spots on an internal wall the other is on the chimney breast. Both near the bottom but above the dpc. Im unsure what method of plastering was used sorry. Could i find out by looking at it?

[NewtonM]

Hi there

I have based my opinion on the property being a solid traditional brick built construction with the external ground levels around 150mm below the internal floor level, fairly decent external brickwork and pointing.

I would hazard a guess and say that the dampness you are seeing is probably due to the salt migration in the brick work as a result of the rising dampness you have had treated.

Rising dampness is caused as moisture rises from the ground into the walls. It carries with it soluble salts which may be deposited in the wall fabric and plaster, as the moisture evaporates these salts, in particular chlorides and nitrates, are hygroscopic; which means that they are capable of attracting and absorbing moisture from the atmosphere when the relative humidity is high. This is then capable of showing up as dampness on the plaster face or in some cases breaking the existing plaster down if not correctly treated with a salt inhibitor.

Hope this helps
Stuart

[sherllin]

HI
yeah Stuart is right. may be dampness is caused due to rising moisture through the wall. It must be prevented before it will damage the wall badly. Prevention steps should be taken ASAP. Dry out the wall.
You must consult this problem with professionals.