Damp problem...whats the solution?

[ripperuk]

Sorry that i criticised your work.

When you removed the skirting did you recognise a sandy render or a typical plaster behind it? Was the back of the skirting sound?

Examine the floor for damp or decay, or even a strong musty odour.

Believe me, 12" to 18" is adequate for access if you can wriggle thro the trap, you push the rubble out of the way. I can well understand your reluctance to crawl. When i've introduced apprentices to the realities of lofts and oversites they often stare in disbelief:
"You mean i have to go down there on my own?"

If the plaster job is indeed render, and the flooring is sound, then "it's" almost certain to be condensation as noseall said.
However, you'll have to lower the ground as advised above, and why not, from just above the DPC, remove an exterior brick or two, per catlad, just to be thorough.

The insulated P/B option requires some thought ( plus you dont have to buy pallets of it ) - why not do whats possible for DIY and wait and see? You can always come back here, in fact i hope that you do, i like to see what happened next.

Don't be sorry, lol...i know it's rubbish.

The plaster used is normal plaster - looks like a multifinish/pinkish in colour?

The floor is sound.

The external of the house is yorkshire stone, so i'd like to leave that if possible - can i do remove the internal bricks instead? Also whats the motive behind removing an external brick/stone?

So what do you recommend?

 

[dann09]

The pink paster is a gypsum plaster and should not have been used in a "damp" situation. However, it's apparently holding up well further along the wall. A render, or remedial plaster, should have been used.

Thing is, if the plaster in-situ has been contaminated by salt chemicals then it will continue to show damage, unless it's hacked off and replaced. However, the consensus is for condensation and the pattern in a corner supports this view.





The motive for gaining access to the cavity is to allow you to examine it for damp/wet conditions, and/or debris bridging the cavity gap, or being piled higher than the DPC.

Perhaps, if you want to open up the wall from the interior, you might lift two or three boards and remove a couple of bricks from below the DPC. Not easy but doable.

I can only supply you with some info. On balance, it looks like condensation, but the call for what next is down to you. Perhaps research condensation options.

 

[ripperuk]

Thanks dann. I don't think its possible to take out a brick from under the floorboards as there is only a foot gap.

If it is condensation, then whats the solution?

 

[catlad]

If you put insulated plasterboard on your wall then you will make it warmer, and that should stop the condensation forming, and if its damp coming from the wall then the vapour barrier will stop that and you will get a warmer house.

 

[ripperuk]

Thanks catlad. Will I be able to wallpaper over it? Where can I get it from? ...I only need a small piece no more thsn 2ft by 2ft

 

[ripperuk]

Thanks catlad. Will I be able to wallpaper over it? Where can I get it from? ...I only need a small piece no more than 2ft by 2ft

 

[ripperuk]

Thanks catlad. Will I be able to wallpaper over it? Where can I get it from? ...I only need a small piece no more than 2ft by 2ft

 

[Joe Malone]

Hi, rising or penetrating damp will leave moisture present at depth in the masonry, condensation damp will not and ends to just affect the plasterwork. That being said, chronic condensation damp will eventually dissolve the calcium sulphate within the plaster making it porous and defective. If you get to this point it needs to be hacked off and replaced. Unfortunately the only way o determine whether you have moisture present at depth is to use deep wall probes attached to a Protimeter or use a calcium carbide test on site. Which isn't equipment most DIYers have access to.

 

[catlad]

try the painting and decorating forum if you want a cheaper option.

 

[ripperuk]

Thank you guys. I think some of you have misunderstood me for which I apologise. I want a cheap option, but not if it does not resolve the problem. My plan is to hack off all contaminated plaster to brick-level anyway. What I wanted to know is what is the smallest piece of insulated plasterboard I can buy? Also once this plasterboard is installed, do I wallpaper directly over it or plaster first?

 

[Pallatrax]

I'm quite sure insulated PB will only come in 2400 x 1200 (8'x4') and your local builders merchant will supply it.

The width will determine how much insulation you gain, and how feasible it will be to just put a patch in; if you used a 40mm thick sheet you'd obviously find yourself with a problem!

How big is the wall?

P

 

[ripperuk]

The wall is big, but the patch i need to do is no more than 2ft height by 2.5ft width and that is on the assumption i will hack off more plaster to avoid contamination...as you can see it is pretty small area to cover.

 

[Pallatrax]

I understand, but if your finish is only 25mm (?) thick you're only going to be able to fit a very insignificant thickness of insulated plaster board, half of which is going to be pb itself...

P

 

[ripperuk]

if i remember correctly, the plaster thickness upto brick-level is approx 3cm. if i can't put on a finish, can i simply paste wallpaper on the insulated plasterboard itself?

 

[ripperuk]

Hello again,

First of all please accept my apologies. I know this is an old topic and that I haven't posted any updates for a long time, but I've had some other personal issues which took priority over this.

Since the last time we spoke, I was still deciding if this problem was damp or condensation related.

Two weeks ago, I cut out the damaged wallpaper (which had gone dark and had a musty smell - See previous pictures on this thread) and decided to scrape away some of the dirty plaster to see if the mould/damp is coming through the plaster or whether it's just on top. From the photo shown below, it seems to be just on top and after scraping away, there is only nice dry plaster.

Does this mean this is definitely a condensation problem?