GRP Roof - Is this to the code?

[FlatWhite]

Hi guys,

Had a full GRP rip-out and reconstruct 6 months ago by my builder (as part of the bigger renovation), but it’s already leaking.

The builders tried sealant on the brickwork edges and said they will add some metal capping to it (which has not arrived), but the leak persists. It also raised a red flag, as I question why they have left the edges exposed. I'm concerned about the skylight installation—it's basically flush at the top edge, causing water to pool (see photo).

This was signed off by private building control but I’m questioning if this is actually up to code (specifically the lack of a proper upstand).

Questions:

1. From the photo, does this look like a compliant install?
2. If it's a fail, how do I best challenge a private BC "Final Certificate"? Do I go back to them or involve the Local Authority for an informal view? More just want to get an official opinion to avoid the back and forth with the builder

Thanks in advance!

 

[stevie888]

Well it's your "builder" that's done the work so the finish is on him. I would expect to see a nice lead flashing over the upstand as a mnimum but a proper coping stone would be best with the roof covering up to it, again with a flashing. The roof light should certainly have an uostand: I'll take a bet the manufacturer's installation instructions say just that: why not check. That will give you documentary evidence rather than a random view from an unknown bod on a forum. Then try your luck.

Private Building Control? Whose idea was this? Many builders think they'll get an easier ride and suggest their use. They are a for profit business and indeed several have gone bust recently causing a lot of problems to householders as these pages have witnessed. Frequently it's "send photos" with minimum boots on site. In my area they are dearer than the LA typically and don't have the local knowledge that helps. I have always steered my clients well away from them

 

[FlatWhite]

You're right about the manufacturer's instructions, but the catch is that this is an 'inherited' window from the old roof. The builder did a full rip-out and rebuild of the GRP but kept the old skylight. The old skylight did have a proper upstand.

My hunch is that they increased the roof's slope during the rebuild, which has effectively 'buried' the top end of the old upstand into the new roof deck. So, while it might have been fine before, it's now flush at the top and acting as a dam.

Since I don't have a manual for this window, is there a 'default' building regulation or British Standard that applies to flat roof windows regardless of age? I want to be able to tell the builder that once they rebuilt the roof structure, they were obligated to bring the upstand detailing up to whatever height?

I can get local building control involved to do a one off inspection and give opinion? just wanted to have an "official voice"..

 

[denso13]

Since I don't have a manual for this window, is there a 'default' building regulation or British Standard that applies to flat roof windows regardless of age?

Just general workmanship standards, nothing specific.

I can get local building control involved to do a one off inspection and give opinion? just wanted to have an "official voice"..

They really won't be interested in that.

 

[freddiemercurystwin]

OMG that skylight is shocking!

Where is it leaking, around the skylight, or around the walls or both or what?

 

[FlatWhite]

We spotted a watermark on the wall/ceiling at the low end of the roof (just one spot), but after opening the ceiling, it's clear the source is further up. The water is tracking down the length of the firrings, following the pitch of the roof. The wet firring lines up with the skylight.

 

[freddiemercurystwin]

That skylight needs replacing or removing, any rooflight needs to be on a raised kerb. There's is no fixing that any other way.

Once that's been done you'll know if it's leaking via the parapet. You could maybe sort the parapet by lapping the GRP up the parapet and over the top, then fit a coping (metal). Of course we don't know what the wall detail is inside, is the wall detail beneath the roof a cavity wall or a solid wall, is there a tray? Questions questions ....