Fixing a hole where the rain comes in...

[irishgrizzly]

Hi,

I have a roof leak and after remembering how Sanzu08 was helped in this thread, I thought I could ask some advice here.

Seeing as how a picture is worth a 1000 words I'll post a few shots of the problem.

Water is coming in around the light fitting shown in the first pic. It only happens during very heavy rain (which we are getting alot of in Ireland for the last two months).

I am renting and the landlady has been very good, getting the original builders out promptly to fix when it first happened. But they are clueless as to what the issue causing it is. They got a guy to put down sealant around the exposed edges – not fixing the problem.

The drain (2) is at the edge of the roof. I've cleared a path of the stones (which I guess are just cosmetic) to hopefully get better drainage to the drain.

The builder thought the problem was the when the wind is blowing a certain direction, the water would blow up under the slates (3).

Does anyone have any thoughts? I hear flat roofs are bad for leaks (this roof is part of an extension built 3 years ago – main part of house is inverted v shape).

Thanks.

 

[irishgrizzly]

*didn't know about 5 attach limit*

 

[mikeyredk]

You need a new roof plain and simple

 

[skunk]

I'm afraid that roof looks like a dog's breakfast. The stones are usually meant to reflect the sunlight off the roof to stop it softening, but in your case I fear it was simply to conceal a bad job. The rain could be getting under the slates, but lifting them to check the state of the flashing would do more harm than good. The roof should have been finished with mastic asphalt rather than torch-on felt: it's too complicated for felt. All they can do is patch one bit after another, but if the patching works you will be very lucky. Meanwhile, invest in a bucket.

 

[GoCubsGo]

No roof should be completely flat, but to the human eye it'll look flat. Obviously there's some drainage but not much. As skunk said the roof wasn't done quite right. I believe the only thing to do at this point is get a new roof. Since you're renting the headache is on the landlord for now, but since it's raining the I think the only thing you can do is maybe tarp the roof and do it in such a way that the tarp is at an angle so water can drain off. The tarp won't hold tons of water so make sure it is situated so there is drainage.

The inside is cosmetic but no sealant is going to fix a bad roof job.

 

[irishgrizzly]

Thanks for the replies.

The roof is not completely flat – unfortunately instead of a gradual gradient from all farthest points towards the drain hole, there are pockets of indented areas were the rain pools.

Would it be possible to lay mastic asphalt over the existing structure or would something more drastic be called for?

 

[Gray-Wolf]

If your in the US, there is a product called wet/dry what can be applied even when the roof is wet. It seals flat roofs well. For the open hole, use a piece of either roofing felt, or fiberglass roofing mesh to cover it, then apply the wet dry tar. It will seal cracks as well. I have used it for years at work on a low fall roof that is similar to a flat roof.

 

[skunk]

Would it be possible to lay mastic asphalt over the existing structure or would something more drastic be called for?

No, you need to strip the existing felt off, check the state of the decking, fix some detailing trim like triangular fillets at the abutments, lift one or more likely two rows of slates, nail down a layer of sheathing felt, fix expanded metal to any vertical surfaces like the rooflight sides, then lay two coats of hot mastic asphalt, trim the edges with aluminium angle, paint the whole surface with solar reflective paint and relay the slates. And that drain outlet needs a proper fitting with a grating in it or it'll get blocked up with leaves in no time. It ain't a DIY job.

For the open hole, use a piece of either roofing felt, or fiberglass roofing mesh to cover it, then apply the wet dry tar.

I believe the "open hole" is actually the drain outlet...