Installing 5V Metal Roofing

[davidshackelford]

For the shed I am building, I will be using 5V crimped metal roofing. The roof is 16' x 10', so the 5V panels are 10' long.

Currently, I just have rafters up. I have seen that in metal roofing, you install boards perpendicular to the rafter, about every 2 ft, under the metal. Would 1 x 4's work for this, instead of 2 x 4's? The only time I will need to go on top of the roof is to install it. What type of nails/screws would I use to install the roofing?

Thanks!

-David Shackelford

[mjpliv]

If you want to use 1x4 purlins then go 16" OC Or even 12" OC, assuming the rafters are on 16" centers. The purlins do more than just support the roofing. They are part of the roof diaphram that, for all intents and purposes, stabilizes the entire structure. The metal roofing does not have enough bending strength to add lateral support to the rafters like a layer of plywood. The purlins provide that support so put them closer together if you are reducing the size.

[Rich]

For screws you should be able to find 1/4" driver screws with rubber washers that will seal the hole as you drive them. You should pre-drill the metal also - you can line up the ends and clamp them and then drill a bunch at a time - this makes all the screws line up and looks very professional.

[mjpliv]

I didn't even see the part about the screws. Anybody who reads my posts has already figured out that when I see a structural issue I develop tunnel vision real fast. :D

Another note on the screws, they are also available with painted or plastic capped heads that can match most roofing colors.