Problems with Poroton Blocks in a dwelling

sonnyblack

Looking for some advice and feedback in relation to Poroton blocks used in a dwelling house belonging to friend of mine. House was finished in 2007 and over last couple of years there seems to be a lot of damp patches forming around and under windows. Saw pictures of radon barrier installation and dpc. Looks all in order so not a rising damp problem I'd say.

Has anyone had similar problems and found solutions. Is it a doomsday scenario of lining walls with dpm and then drylining the whole house?

Any feedback welcome.

Calahonda52

Whats the heating and ventilation profile in the house?
Is it all windows?
Any pictures of internal damp and matching position externally

fatty pang

sonnyblack wrote: »

there seems to be a lot of damp patches forming around and under windows. .

Does the as-built match the architect’s detail. Was the architect’s detail ever going to keep water out in the first place ?

sonnyblack

Calahonda52 wrote: »

Whats the heating and ventilation profile in the house?
Is it all windows?
Any pictures of internal damp and matching position externally

Bungalow, Underfloor heating. Not too many windows. nothing extraordinary

Inside picture attached

sonnyblack

sonnyblack wrote: »

Bungalow, Underfloor heating. Not too many windows. nothing extraordinary

Inside picture attached

Should also have attached outside picture in same location. See below

sonnyblack

fatty pang wrote: »

Does the as-built match the architect’s detail. Was the architect’s detail ever going to keep water out in the first place ?

Not sure that its anything to do with Architects detail. Feel its more to do with poroton system.

homewardbound11

Only a novice but when was the patio paving put in. It looks higher than the dpc

sonnyblack

homewardbound11 wrote: »

Only a novice but when was the patio paving put in. It looks higher than the dpc

Good point but I don't think so. it's below dpc level. The problem is all around the house mainly below windows but also in the reveals

BryanF

Take out a window, check dpc

sydthebeat

http://touch.boards.ie/thread/2057633745/1/#post100660410

I think you might have a case of what's talked about in the above thread.

Made worst because you've a single leaf building system.

Anywhere you've ground level less than 150mm from the doc line you should, at a minimum, install an acco drainage channel.

kieranhr

I don't think it's anything to do with the distance between the ground level and the external DPC, not if it only happens at windows.

There are three other things going on in that photo, that again are unlikely to be causes, but you can't rule them out just yet - the crack in the wall at cill level, the downpipe directly outside the damp patch, and the gatepost which is probably fixed straight through the waterproof external plaster.

But the more likely cause for me is the junction between the window and the wall, or less likely, something happening at eaves level above that again.

Water ingress is notoriously difficult to rectify, because where it shows up can often be quite a distance from where the problem is actually occurring. I would start by taking one affected area and fixing a clear polythene sheet over the entirety of the outside of the window above. Pick a room you don't use that much, because it could be there for several months. make sure it is very well sealed on all sides, so that no rainwater can get in. If the wall dries out, and stays dry, then you've identified the window as the problem.

Calahonda52

As above, is there a groove for the drip on the underside of the sill
https://techboard.vectorworks.net/ubbthreads.php?ubb=download&Number=6958&filename=UK%20sill%20and%20sub-sill.png

Thanks for the pics, load up a few more when you can as you say its
The problem is all around the house mainly below windows but also in the reveals

Calahonda52

OP: what was the end result here?
Thanks