I have a big 40x60' pole building planned. No sides. 10' at the eaves. 4/12 pitch. sheeted roof. This structure will be over the top of another structure and will provide some covered storage on both sides. The builder quoted 29 gauge. Is that the norm? Seems like 26ga. would be preferable. Is 29 ga ok or no.

What’s supporting it? If purlins, what spacing? Did they give you a cut-sheet on it or a brand name and model so we can look it up?

From a structural engineering perspective, commercial-type pre-engineered structures with metal roofs are often 26-gauge metal deck in the southeast. For roofs acting as a diaphragm to transfer lateral loads and serve as the base for insulation and a roofing material, 22-gauge is common. I can’t recall seeing 29-gauge proposed on a structure I’ve worked on.

They used 28 gauge 40 year on my back building. Trusses 4' center with 2x4 purlins and 2x6 studs on 2' center.

29 might be ok with decking underneath it in a non-hail area. For the pool barns in MI and TN and the garage in FL, we went with either 26 or 24. The roof on our new house will be 24 and there’ll be 5/8” decking under it. I really don’t know, but out of 10 buildings between my dad, brother, and myself, nobody has suggested 29 gauge.

29 Gauge is the norm for pole barns here in Ga.
Billy

Thanks guys for the info. Helpful. This structure will have 6x6 posts on 10' centers. Double truss' on the five interior posts sets. Single end truss'. 5/8" roof sheeting. Sounds like 29ga. would be minimum metal thickness. I have asked the builder for an upgrade to 26" ga. cost estimate.
Thanks again guys.

We've made millions of tons, (literally) of 29 Ga roofing material. Make sure it's Grade 80 with Galvalume coating. If installed correctly it will last 40 or 50 years.

Thanks 08 C, that is great info. Appreciate it.

If you go with the heavier gauge it will probably be a Grade 50 galvalume. If painted your good, if bare with a hex acrylic coating need to watch for fingerprinting.