Can anyone advise if a membrane is required under a GRP flat roof on a loft conversion? We have a little bit of membrane poked up under gutter and under lip of GRP but it flaps about in the wind and can easily be pulled out. 

 

I'm concerned that if it isnt correctly fitted the water will drive behind the GRP and behind the facias down. 

 

I've attached some images. 

 

I'd appreciate any advise on this matter. 

 

Thanks Steph 

That does not look like it has been flashed well at all. Is the black stuff at the bottom the gutter and the shiny metal bit some sort of facia?

I can't really work out what is going on from that picture, any chance of some more, a bit more zoomed out.

 

Basically the GRP covering is instead of a membrane, but it does depend on what you class as a membrane.

GRP has a membrane underneath and it kept flapping, blowing out so they siliconed it down into the gutter. I pnmly know this i managed to get access up thr guttering. Any other image attached. 

 

Thank you 

The membrane isn't under the GRP it tucks behind the guttering.. Im wondering if it was placed after roof fitted as the rain use to run down the back of the guttering. Thank you 

Apologies that top message meant to say there is Scaffolding back up so I managed to get access to look at guttering and flat roof. They have siliconed the membrane into the guttering and the Grey is also some sort of silicon / putty. 

The GRP work looks alright, think the rest is a bodge and it will almost certainly give you trouble.

Not sure what the solution is apart from replacing the membrane with something more rigid.

Apologies that top message meant to say there is Scaffolding back up so I managed to get access to look at guttering and flat roof. They have siliconed the membrane into the guttering and the Grey is also some sort of silicon / putty. Should the membrane sit under the GRP and over hang a little? 

26 minutes ago, Steph83 said:

Should the membrane sit under the GRP and over hang a little

I would think so, the idea is that the wind cannot blow rain backwards.

 

To me that membrane looks like DPC (stuff used in brick walls to give a damp course). It also looks like the GRP roof does not extend over the gutter properly hence rain running down the back of guttering. Silicone to the guttering is a bodge. Very difficult to see from pics, anyone else?

Edited June 16, 20215 yr by joe90

I reckon the membrane was tucked under the grp after install. 

6 minutes ago, joe90 said:

Silicone to the guttering is a bodge

Yes, and it does not stick that well to GRP.

4 minutes ago, markc said:

I reckon the membrane was tucked under the grp after install. 

I agree.

Thanks all, I appreciate your advice ?