Roof Weight

Desch75

I have a customer concerned with the weight of GAF Grand Canyon Shingles- 450lbs per sq. The Trusses are 24" (2x10's) on center with a decking of 1/2" plywood. There is minimal sagging with the old roof. My feeling is the Grand Canyons are fine and the dimension of the shingles will disguise the sagging. Opinions?

jcalvin

450lbs per square is minimal compared to you standing there on the roof. This is 4.5lbs per square foot. I would be more concerned with the 1/2"decking on 24" centers if I were them.

__________________
Cal


You hired WHO

J-Peffer

Around here, we get 3-5 foot of snow on some roofs.

Got to bid one that did cave in this year. Framing is done, and it's the first roof in the spring.

I can't even imagine what 4' of heavy wet snow would weight per 100 sq foot......

Grumpy

24" oc 2x10's are fine. Yeah the 1/2" may be a problem, we see alot of it around here.

Here are three options. Have her pay an engineer to approve it. Have her pay you to do the research into the original submitted plans at the building department and see if there are any design loads. Upsell her to a light weight Synthetic like Davinci or Lamarite I like option 3 best.

Obviously if all else fails sell her the standard architectural

Jake Stevens

What's the pitch on the roof? Does it have collar ties? If the roof is sagging already I would add raffters in between the raffters that are there, collar ties, and install 5/8" T & G decking, then you can put on any shingles you want.