Diagnosing Wall Dampness

Agricola

Recently noticed that the wallpaper on one wall of the house was peeling, so decided to rip it off to see what the problem was. This is a 30 yr old bungalow with no previous damp issues btw. Its a bedroom wall, on the other side of which is a car garage. The damp doesnt appear to be rising as theres no tide mark from the ground up. Its mostly concentrated in one corner where the wall meets another wall which is external, plasterboard finished. Its goes from the skirting board in a more of less even 2 foot wide strip all the way up to the ceiling. Apart from that theres just the odd dark patch on the wall, otherwise it is bone dry.

In the attic above this bedroom ive checked for any leaking tiles, signs of wet rafters / insulation, and there doesnt seem to be anything like that. The gutters arent blocked, and theres no sign of water spilling in from them into the attic. Im beginning to think the problem is due sweating or condensation but Im unsure. Black mould spots are visible which Ive read indicates condensation. But the way its just appearing in one corner is odd. 2 years ago we had double glazing and oil fired CH put in. Im wondering with the extremely low temperatures we've had in recent weeks, is this problem a result of poor ventilation, and a wall which would be warm on one side and extremely cold on the other?

Any pointers very welcome!

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gsxr1

Agricola wrote: »

Recently noticed that the wallpaper on one wall of the house was peeling, so decided to rip it off to see what the problem was. This is a 30 yr old bungalow with no previous damp issues btw. Its a bedroom wall, on the other side of which is a car garage. The damp doesnt appear to be rising as theres no tide mark from the ground up. Its mostly concentrated in one corner where the wall meets another wall which is external, plasterboard finished. Its goes from the skirting board in a more of less even 2 foot wide strip all the way up to the ceiling. Apart from that theres just the odd dark patch on the wall, otherwise it is bone dry.

In the attic above this bedroom ive checked for any leaking tiles, signs of wet rafters / insulation, and there doesnt seem to be anything like that. The gutters arent blocked, and theres no sign of water spilling in from them into the attic. Im beginning to think the problem is due sweating or condensation but Im unsure. Black mould spots are visible which Ive read indicates condensation. But the way its just appearing in one corner is odd. 2 years ago we had double glazing and oil fired CH put in. Im wondering with the extremely low temperatures we've had in recent weeks, is this problem a result of poor ventilation, and a wall which would be warm on one side and extremely cold on the other?

Any pointers very welcome!

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I would bet on your observation being the problem.

Agricola

gsxr1 wrote: »

I would bet on your observation being the problem.

Is this the best this forum can do?

brendankelly

My view is that your external wall is soaked and covered up with drylining. The moisture is seeping from the external wall inward and back along the wall and the drylining board. I find it strange that the dampness is the same with at the top as at the bottom. The lightly cause is if the roof of the garage is separate there is a leak in the lead flashing

okofen

looks like condensation which is developing into mould, very common on north facing walls, but i would say you are right in your prognosis, there is a great product called a drimaster. www.drimaster.ie which would solve your problem.
it is the most cost effective way to ventilate a property, guaranteed to get rid of condenation and mould aswell as creating a much healthier living environment.

gsxr1

Agricola wrote: »

Is this the best this forum can do?

Im afraid that your conclusion is the correct one. If you have confirmed there is no leak then it is down to condensation. Which should dry and return to normal when conditions return. Why else would it only happen now after 30 years . Because in 30 years we never had a -19 degree week. This is happening everywhere.

Another suspect is blocked drainage on your roof due to ice. Water is diverted into the wrong places while the thaw was going on. Which now cant be traced

If you read a few more threads on the forum you will find that the same advise in ways to deal with damp north wall conditions is being repeated daily .

Hope you get to the bottom of it .

Keep the room warm and well vented. Wash and dry wall with mold cleaner.

Agricola

OK, thanks all.

I'll go about cleaning and drying it out so.

Buford T Justice

If its only recent, then i'd say its down to the weather. Other than that it looks like there is a leak coming from the top of the wall down.

Spread

If the studwork and plasterboard was fixed to the external blockwall before that wall was rendered/drylined then any moisture in the wall will migrate inwards through the plasterboard. Cracked or defective rendering will cause lateral penetration. I doubt that it is condensation. Is the inside of the external wall plastered?