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Alang Alang is offline
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Default Water ingress problems around French windows.

On Thu, 19 Feb 2009 17:34:13 GMT, Stuart Noble
wrote:

Alang wrote:
On Thu, 19 Feb 2009 16:14:50 -0000, "Bob Mannix"
wrote:

"David Chapman" wrote in message
...
Greetings,

My son and his wife have been renovating a 1930s detached house which
they recently purchased, and they have had an early double-glazed sliding
patio door replaced by a modern double-glazed pair of French doors
(installed by Sutton Windows). When this was done the window installers
noticed that the old door had been inset further than it should have been,
and that some bricks on either side had been hacked away in order to
accommodate it.

The new doors (see the picture at
http://www.minda.co.uk/dave/HouseBack.jpg) were manufactured to the
correct size for the aperture but, in order to fit them properly




One diagnostic you could try is wetting the wall with a hose to a limited
height, waiting to see if the damp appears, then trying a bit higher etc.
Once the damp appears you have a better idea of where it is getting in and
can then narrow the search down a bit.

Expanding foam is for filling gaps and for fixing in position at best. It is
not a seal.


I'd take a close look at the mastic around the frame too. It only
needs a pinhole to start wicking water through


What I've done in the past is hack off an inch or so round the frame,
and fill any obvious cavities with foam. I then put some greased (25mm
wide?)strips of hardboard against the frame and re-render up to them.
Slip them out when the render is dry and you have a nice 3mm gap for a
bead of low modulus silicone.
Not always easy to pinpoint the source based on the position of the damp
patches.


I had one on my bay window when we moved in. Tiny crack in the
flashing at one end and water stain right in the middle