Marley Mendip at 11 degrees

[AddF]

I have some building work being completed by a builder with a good reputation locally. However, he’s made a major error in his installation of the roof structure on the dormer extension. The roof should have a 12.5 degree pitch, but he’s installed it at 11 degrees needlessly. He should be using Marley Mendip tiles on this, but they state they only go to 12.5 degrees. Has anyone got experience of using these tiles at 11 degrees without any issues? Realigning the pitch to 12.5 is now a big job, as it is a shared roof so it can’t be lifted at the top end, it needs lowering at the wall end (where he has already installed windows and hanging tiles). Thanks for any advice.

 

[kp00110]

The question is will he come back to fix it (and do you trust him to come back) if it does leak/fail and when the manufacturer wash their hands of it because it was installed out of specification.

If he is reluctant to fix it properly now, he definitely wont fix it properly later once your whole loft is fitted out and its a major major reconstruction and cost.

I would tell him to bite the bullet and fix or change tiles?

Seems to me the risk and future costs will no doubt end up sitting with you if you agree to let him continue

 

[matlob]

My architect suggested I may need to use Onduline sheeting under the tiles if the pitch was too low. That may be an option if the tiles aren't on yet

 

[datarebal]

Planum Low Pitch Roof Tile​