I renovated this house, and newly constructed 4 barrel dormers attached to a pitched roof. 3 1/8 X 7 1/2 glulam arches 32″ oc. supported by 6 3/4 X12 glulam beams formed into 4 engineered 3 sided “trusses”.
Standing seam 24 ga metal over Titanium PSU peel n stick, 1/2″ plywood. Sheet lead was used to form the valleys, and here after 4 years the lead is cracking open across the valleys.
I’m looking for a solid long term solution. Ideally a 3 section radiused valley made out of metal would be my top choice.
My concerns around using copper would be because of the dissimilarity of the metals.
Anybody done this in fibreglass?
I’d rather not use torchon unless its protected from the UV.
Constructive mindful professional solutions and suggestions are welcome.
Thanks, Pete.
Replies
I have a lot of experience w/ lead valleys with my UK company as a lot of the roofs there are constructed with lead valleys and slate shingles. To repair cracks and leaks my roofer there will weld lead sheets over the damage, but that is very old world technology and finding someone with experience welding lead is very hard (even in old world U.K.). I would never consider installing a lead valley with my US business as I’m in a region that can see a lot of heat. Lead doesn’t perform well in extreme heat, probably why yours cracked. The U.K. weather is really mild, so it works well there. If the weather in your region is mild you might be ok staying with lead. I’ve only built 4 large sized eyebrow roofs in my lifetime all in the US. Two of them were installed with copper roofing and flashing by trained pros, worked great. The other two were installed with your average asphalt shingles. On those we basically installed the valleys with a step flashing type procedure. We used a really good quality EPDM roofing making our own step flashing by cutting 12” wide strips. We primed and glued each piece of step flashing to one another, but only enough to keep the wind from lifting them. Wanted to make sure water could drain out of step flashing if water ever made its way in. We half lapped each piece of step flashing, so the rubber in the valley was twice as thick as it would be in a flat roof application. EPDM will break down over time with UV, but a reflective coating will help with that. I’m sure there are some very specialized products available and pros with a specialized knowledge to install them out there, but this is what we did for our projects with limited budgets.
Thank you for your input, and sharing your real world experience. These are the kinds of pointers I value. Pete