Maximum steel gauge?
Hi all – We’re looking at building a steel framed home with mineral wool or EPS on both sides of the wall (might go with a SIC Systems or ThermaSteel solution). I was thrown by the documentation for HardiePlank siding. It says that steel framing has to be 20 gauge min and 16 gauge max.
Why would there be a maximum gauge? What do they care if someone uses a heavier gauge? A minimum I understand, but I’m confused by the maximum. Any ideas why they would stipulate this?
Nichiha didn’t stipulate a max, just an 18 gauge min. The James Hardie language is in the first sentence under General Requirements on Page 1 here: https://www.jameshardiepros.com/getattachment/513223b4-054b-4112-ab6b-38974c62c9cb/hardieplank-hz5-us-en.pdf
Thanks for your help.
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Replies
Probably too heavy of a steel stud and there will be so little give when you tighten the screw that you’ll crack the Hardie plank; or perhaps thermal cycling will. Aside from those, I can’t think of a reason.
If you're trying to use heavier steel studs but still keep the Hardie warranty, you could probably fasten some wood strapping to the edge of the steel studs and keep the Hardie people happy by fastening the siding to the wood strapping.
Bill
It might also have to do with the approved fasteners. Screws might strip, powered pins might deflect.
Yes, most likely this. They specify exactly one option for each. The #8 screws probably don't have a big enough thread pitch to span thicker than 16ga steel.
Probably more likely that their screw can’t penetrate the heavier stud. 16 gauge is pretty beefy — those studs don’t have the usual flop’n’flex that the more common lighter ones do.
Bill
Stud gauge aside, having to screw Hardi-Boards is a lot slower than nailing. I did it on two very small jobs to see if it eliminated gapping at bottom edge, and wouldn't like to do it again.
Why did you think a screw would work better than a nail for the gap? I always just thought nails were more likely to blow out edges occasionally, but go in fast, while screws might be more secure but also WAY slower.
Can’t say I have a lot of experience hanging siding though.
Bill
The screws suck the board down better against the one below. Nailing you occasionally end up having to pin the bottom edge.
Malcolm, why wouldn't you like to do it again? Speed?
Yes speed, and it is much harder to avoid sinking the head of the screw below the surface than with a roofing nailer.
I experimented with screws but found that the tapered heads really damaged the fibre cement.
Trevor, truss head screws will have less tendency to split the planks. The downside is the head can’t be driven flush, so you get more of a gap. Always a tradeoff, unfortunately.
Bill