leaking flat roof

20 Sep 2007
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United Kingdom
We had a flat roof installed as part of a loft extension and it is covered in felt. The builders then cut a hole in the felt to put a flat window in. This is now leaking and they are claimed to have fixed this with a sealant. Will this work or will they need to refelt the roof to ensure it is properly waterproof?
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What sort of window is it? It should have a proper flashing on there which shouldn't need sealant (which will leak).

Can you do a photo, this sounds dodgy.

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It is a "bubble" window which cant be opened and it sits on the flat roof. I havent managed to venture out on to the roof (its quite high) but I know the roofer was talking about needing to refelt it but i think they did a quick fix with a sealant. (they arent very trustworthy).
What makes you say they aren't very trustworthy? Sounds like you have a polycarbonate dome on there, If the dome was an afterthought after the roof was laid then that will make weatherproofing slightly trickier, but it shouldn't leak if they know what they are doing. Is this on a roof dormer then?
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yes, thats exactly what happened. the roof was laid and then they cut out a hole for this polycarbonate window.
hi just woundering if any 1 can help as i am getting a loft conversion done atm the roof has been leaking in a few areas... now the roof has now been done from the outside as off yet but they have put the plasterboard up and brought plaster in the house.... i ask the workers that not 4 the cellening is it they sayed no but it was. now i have wet plasterboard plaster over and the roof still leaking what can i do ??? i would love 2 replace it but i dont want the workers beening funny about it as i brought it up 2 the plaster when i took him up a cup of tea and he wasnt 2 happy that i was question him on it ... as far as i know if the plasterborad get wet it never going 2 be the same will this cuz mold???? if it not replace??
How do you know the roof is still leaking if the plaster is still wet? Wait for the plaster to dry, and if you start to see wet patches then you'll know the roof is leaking. Ideally you should be asking this question to whoever is in charge on site, and ask exactly why the roof leaked and what he's done to fix it.

Ultimately if the roof is leaking at the end of the job don't pay them a penny until they have fixed it.
yes, thats exactly what happened. the roof was laid and then they cut out a hole for this polycarbonate window.
Is your roof a felt roof? if it is then they should have torched on flashings around the skylight. Silicone sealant is no use for this type of job.

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