Window fitters - is this their fault ?.

[dave3011]

Dear Colleagues,

I had upvc windows fitted to a bay window in the top room which has a flat roof ( with flashing on it ) by professional window fitters. ( pictures attached below - two of them show the upper bay roof with the wooden windows removed).
I've now noticed after the UPVC windows being installed ( after a heavy fall of rain ), that damp patches ( starting to turn black ) have formed near the edges of where the windows are.
Does anyone have an opinion on how water is getting in and is it due to a faulty window installation ? (as I did paint the flat roof flashing with waterproof black sealant - so don't know why water should be getting in).

[danny4g]

Is it definiately water ingress? Did you by any chance have vetilation in the old windows? Or ventilation bricks? There is a chance it could be condensation.

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[Ktuludays]

Looks more like mould from condensation than water ingress

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[Bob225]

The bay roof has settled if its a old flat roof it may of cracked just due to age

it looks like there were issues before the windows were done - the facias look they need some tlc

[big-all]

my thought
you have replace cold draughty window that i assume attracted terrible condensation
you now replace with nice warm windows so the moisture in the air now condenses on the next coldest surface
solution is to both increase the insulation in the top off the bay it looks like its missing at the front edge
and reduce the amount off moisture in the air

[dewaltdisney]

I think the flat roof on the bay has been possibly damaged during the window installation. If it is old lead then it is possible to get splits in it and similarly if it is felt. Neither like to be disturbed. I suspect that it is rain water leeching through causing the water stain. You need a roofer to get up and inspect it.

DWD