Roofing material covering flat roof to inverted dormers

[hoyjoh]

Hi there,

I have recently built an extension and the roof meets the existing house slightly higher than the exsiting window sill level. Therefore there are two flat roofs under each window forming inverted dormers. The tiles to the roof are double romans and I'm not sure what will be the best material to cover the flat roof sections. I could use lead but was considering an alternative in GRP, the issue being I'm not sure if its possible to lap GRP over profiled tiles?

Does anyone have a previous experience or alternative options?

Thanks in advance.

 

[Alastairreid]

Use code 4 lead as an apron to the tiles then your grp to the rest.

 

[datarebal]

seen many grp to lead failures.. I would plumb for lead

 

[catlad]

You can not stick grp direct to lead it won't last.

 

[hoyjoh]

All, thanks for you comments I wasn't planning on sticking the GRP directly to the lead, I would have have installed the lead flashing over the tiles and then lapped a GRP flashing over the lead on the flat section of the roof (the flat roof has a 1 in 40 fall). Your comments would be appreciated, however I am swaying towards doing the whole thing in lead.

Thanks

 

[hardmetalking]

Zinc?

 

[datarebal]

what size are we talking?