DIY Doctor

Main navigation

Grp valley on bungalow extension and help needed on installation

Postby mcmj » Mon Jun 07, 2021 3:37 am

Good morning all. I am having a kitchen extension in my bungalow and am concerned that the GRP gullies have not been fitted properly by the roofer. They have sanded strips up both sides but have been told by the builder that they don’t mortar them in anymore. Further, there are no gully boards to support the gullies and no strips of felt running under the gullies. Also, the existing and new felt has not been overlapped under the gullies. It just goes about 2 inches over the edge of the gully and I can see daylight coming in.
I think it will leak?
Lastly, should the top of the gullies be treated with lead?
Thanks in anticipation of your help. Mark C Johnson
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Mon Jun 07, 2021 3:14 am

Postby stoneyboy » Wed Jun 09, 2021 9:11 pm

Hi mcmj
Detail depends on the type of valley gutter fitted, open or dry fix, the latter has a central ridge. In either case there should be valley boards and felt under the grp channel. The need for mortaring the verges of the valley gutter will depend on the type of tile and the size of the gap between the tiles and the grp.
With a dry fix valley the cut tile edge should be fitted to the central ridge so no mortaring may be needed.
Lead is not used over a grp valley.
Regards S
Rank: Project Manager
Posts: 4621
Joined: Wed Dec 10, 2008 6:44 pm

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics