Damp walls after water leak - how long till it's dry?

[morkhans]

So mainly due to [-]stupidity[/-] reasons I won't go into. The tenants next door had a long term leak that went [-]unresolved[/-] undetected in their bathroom. This resulted in damp and paint damage on my side of the party wall. The leak was fixed 6 weeks ago and the builders came this week to prime the wall for painting, but stopped because they found the wall was still too damp. Initially the landlord (who's in the building trade) suggested a time frame of 2 weeks. So I thought 6 weeks would be ample. After telling him what the builders said and if it's possible the leak is still not properly fixed, he's changed his tune to 3-6 months for the wall to dry.

So questions
1) What is the recommended time frame for a wall to dry? In this case I believe the bulk of the moisture ran down to the foundations and then got sucked up the wall (cement brick).
2) Is there some way I can measure that a wall is in fact getting dryer? i.e. I want my insurance to send a man out and then again in 2 weeks time. If there's no improvement then surely there is still an issue in the unit next door?

 

[biometrics]

Had a leak fixed recently. They had a small electronic gadget they touch to the walk that measures moisture. So perhaps ask them (Seek a leak, detect a leak etc).

 

[morkhans]

Ok thanks. Got hold of the assessor he's going to send someone to do a test.

 

[gripen]

I'm in the same situation - similar problem. How long did the wall take to dry in the end? Apparently the leak upstairs has been fixed but we're not sure. I'm just wondering if it will really take that long to dry before we repair the damage. The other issue is that we want the upstairs owner to pay for the repairs, if we repair now and it still leaks... we will struggle to get them to pay. How did you handle this?

 

[Zewp]

We had a leak that ran for about 4 weeks while I wasn't home in December 2011. It took almost a full year for some of the walls to get dry. I painted it last year November and the paint still bubbled from all the moisture. I tried again in February and luckily the paint stuck then.

 

[Arthur]

It can easily take a year or more -- depends on how the moisture is to escape.

Paint/undercoat seals the surface, so if the wall is largely painted but wet inside, the onlyh way out for the water is gravity, down to foundations, which are themselves sealed so moisture from ground doesn't rise.

The proper and professional way is to strip all undercoat/paint/sealing off the wall on both sides, use heaters and fans with open doors/windows to dry the wall for about 2-3 weeks, then prep and finish the walls again. If very water-logged, the plaster might have to come off as well. Of course this is so intrusive that most people take a shortcut, dry the surface/plaster only, and seal with a waterproof prep before repainting. This shortcut can produce major problems years later, when the water has sunk down and is trapped by the damp sealer.

 

[Hosehead]

I've had a house where the walls never dried.

 

[morkhans]

Looks like its only dry enough to paint now. So yes looks like 6-12 months is about the time it takes.