Hygroscopic salts?

[philipb82]

Thanks for all your help and advice.

Phil

 

[philipb82]

Just to add, the company who insulated our walls use glass wool and ive researched it on the net. Apparently this type of insulation doesn't allow water to penetrate it so surely the problem can't be down the insulation?

Your thoughts are welcome

Phil

 

[Richard C]

Just to add, the company who insulated our walls use glass wool and ive researched it on the net. Apparently this type of insulation doesn't allow water to penetrate it so surely the problem can't be down the insulation?

Especially if the damp is on an internal wall

 

[philipb82]

So cavity wall insulation problems can't affect internal walls in anyway? Sorry if my questions are daft. I just want to gather as much info as I can

Aswell as these very helpful posts I've also got a friend coming round to have a look.

Phil

 

[trowelmonkey1]

moisture has to be coming from beneath the wall if it's internal. the guys have nailed it me thinks.

 

[Richard C]

So cavity wall insulation problems can't affect internal walls in anyway?

I can’t imagine any scenario where it could.

moisture has to be coming from beneath the wall if it's internal. the guys have nailed it me thinks.

Absolutely

 

[mac391]

Your cavity insulation (1 year ago) could well be the single issue that is causing your moisture problems. salts on the walls appear after water/moisture passes through permeable building materials (your walls & render/plaster). The moisture collects salts such as nitrates and leaves them as a deposit on the plaster surface, evidence that moisture has passed through the brickwork. And yes, this can be caused by the wrong application of cavity insulation if it has bridged the damp course.. An independant surveyor is probably best to help with this. £200 ish for a written report to clarify. Vinegar is of no use here my friend. It could well be something else causing the problem but the timing of the cavity insulation makes it a suspect.

Hello
The walls in question are interior, the plaster behind looks alright.

I did actually mention it was interior walls in my question and I promise you I'm not winding anyone up.

Phil

My fault then, the cavity insulation bit was a distracting red herring I wasn't entirely on the wrong track though, just the cause; I agree with the others.