Expanding foam in new valley?

[Mezmeron]

I'm in the process of having roof valley replaced as we've had a leak that's come through the bedroom ceiling. It appears it might have been the chimney flashing causing the leak, which is now also being replaced, but we need the valley replacing as it was an old concrete one and needed doing.

The guys doing the job seem pretty good, but today I was informed that the new fibreglass valley was 9 inches wide, and the old one was 12. They seem to have cut up some tiles to make up the difference, and put a load of expanding foam into the gaps, and I'm not too happy about this. Is this normal?

Thanks.

 

[^woody^]

Normal for cowboys, maybe.

Not normal for tradesmen.

 

[Mezmeron]

Thanks. Should I get them to do it again? Or get someone else?

 

[geraldthehamster]

Cured PU expanding foam degrades in UV light (that is, if exposed to daylight). What they have done is wrong.

 

[freddiemercurystwin]

It needs redoing with the right sized valley. It will leak if its not done again. I suspect if you were able t climb up and take a better pic it would look horrifying!

 

[^woody^]

Valleys are one of the worst jobs on a roof. Difficult to replace correctly, and unforgiving if not done properly.

It's a case of either a straight-forward like for like replacement, or a replacement for a different type and size - but then that must be altered correctly.

With a narrower valley, the first thing to consider is if it is actually suitable to make it narrower. If it is, then the tile laths need to be extended and bigger tile cuts fitted - not additional pieces of tile - and this would mean a lot of additional work to be done properly - and not the shortcut and cheap job that the roofers think it will be.

Definately no foam - that gets a Sheriff Silver Star - proper mortar or dry valley only.