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Drainage in new double glazed units

Postby CJ474 » Wed Feb 17, 2010 11:20 pm

Hope somebody out there can help! In December 09 and January 10 (yes, just last month) we had 3 new windows fitted to our home. These are leaded, double glazed units. First we had one done in Dec, then in January, the other 2.

When checking the units in January, a day or two after the second 2 were fitted, I found that when I opened the windows, that water was sat in the sill, (underneath where the window unit would normally be when closed).

Our fitters came back and tightened the window closures, plus have put more sealant on the top of the worst affected (fitted first) unit to stop water leaking in behind the window and down into them (apparently the first lot of sealant was “sagging” and water was getting down through it.) Our home had wooden style cladding on the outside by these windows, which is apparently why this sealant was put there.

This does seem to have helped the problem, but one of the windows is still wet in this gulley, even this morning after just a frosty, not as far as I'm aware, rainy night. Some days it is totally dry though, even if it's rained. I am told that there will be some amount of water getting into the space, that’s why there are drainage holes there. However, I have never seen water gathering here in any other double glazed units, so am unsure about this!

The fitter, when he visited last, said that he would return (yet again) with “stronger sealant strips” to ensure the problem was solved this time. He has apparently now gone on holiday, and the company are chasing payment for the final balance as the lady there said she had been told (presumably by the same fitter) that they had done all they could, and the next step would be to call in the manufacturers, as it must be a manufacturing problem. And that the manufacturer would charge them if no manufacturing faults were found. Screws on the opening mechanism in the bottom of the windows have rusted, but again, the fitter said that he would change them for new ones when he comes back, once all was declared to be well and dry.

I don’t want to get into a situation where the water weakens the unit (and possibly the others too, although they do now appear to be OK, but it doesn’t leak every time there is rain, I think the wind direction or quantity of rain must have something to do with it) where the fitters blame the manufacturers, and vice-versa, with nobody accepting responsibility and us just having to just go elsewhere and get completely new windows in a year or two’s time if they fail in some way.

The company are FENSA registered and, as far as I am aware, have a good reputation locally or I would never have dealt with them in the first place. Am I being too picky?

Hope there is some help out there! Cheers for reading. CJ
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Simply Build It

Postby stoneyboy » Fri Feb 19, 2010 7:27 pm

I assume you have upvc windows.
The rebate area at the bottom of the opening casement should have drainage holes which feed out onto the cill. If you have any fixed windows these should also have drainage channels.
I do not understand why your window fitter thinks sealant will solve this problem unless the windows were badly fitted.
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Postby CJ474 » Sun Feb 21, 2010 11:58 am

Thanks Stoneyboy.

Yes, the windows are uPVC, and yes, there are drainage holes there but the water doesn't seem to go down straight away, it sits in there.

The sealant was put on the exterior of the house, above the window. The last window we had there leaked, which was was apparently because water was seeping in via a decorative timber above the window unit.

Hope this makes sense, it's difficult to describe!

Thanks again!
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Postby paulcourtyard » Fri Jun 25, 2010 7:02 pm

It is normal for water to gather on that strip, when it gets high enough, it should go down the drain holes. It will have no effect on the seal of your Glazing units, infact if you look at the bottom of the sash that opens, you will see drainage slots that drain onto the section you are worried about. The seals around the Glass on the outside nearly always leak, so water goes in there and then comes out the bottom of the sash, then down through the slots in the cill frame and out onto the outside cill. This is perfectly normal.
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