Would screws really snap?

[23vc]

Sorry yet another question on my roof which I’ve not even started yet.
I know the general opinion is nail the rafters to wall plate at top and bottom of roof, but I’m paranoid that I’ll have to change it if the bco doesn’t like it, so am leaning towards screwing it. Does anyone actually do this? I don’t think I’ve ever had a 5x80 goldscrew or whatever snap, they just bend, so I’m kinda hoping I should be ok with screws? I can always bang some decent sized nails in too once it’s been signed off. Any opinions welcome!

 

[DIYer Damo]

I screwed mine down but all the research I did also suggested nailing too ( they’ve been nailed down for a long time) so I don’t believe it matters so long as either are a sufficient gauge.

 

[23vc]

Cheers planning on something like a 5x90 but seen suggestions on here(noseall I think) to use small headed screws but failed to find any long enough

 

[DIYer Damo]

I used 5 x 100 and tried me best to countersink. Not easy as screws going in at an angle but they sat deep enough to not obstruct my insulation between the joists.

 

[^woody^]

Don't forget to post back in 10 years time and tell us where the roof is.

 

[23vc]

Lol. Will do

 

[stuart45]

I think woody means that screws don't have the shear strength of nails.

 

[^woody^]

What happens with screws in these situations is that they can corrode right at the junction between the two timbers and then fracture at a slight bit of movement. Plus the roof and rafters will move ever so slightly, which stresses hardened metal.

So that's why they are not used.They may be OK, or they may not. Nails will be OK.

 

[23vc]

Ok cheers, I might just nail it then. To be fair I can’t really see how I could have got it sufficiently wrong to need to have to remove any rafters. Birds mouths have ended up slightly deeper than expected but still only about a third depth, that’s the only thing that I guess could be an issue.

 

[pilsbury]

I screwed my roof together. 3 per joint. Many would say that’s a reason to nail.

 

[23vc]

Those drywall screws will be fine mate.

 

[pilsbury]

Those drywall screws will be fine mate.

They were on special offer

 

[catlad]

Screws are weak compared to nails.

 

[John D v2.0]

blu tack has come on in leaps and bounds in the recent past, may be worth a try?

in seriousness though, screws have to be a lot more rigid to transmit the torque, which makes them more brittle. Nails on the other hand are very malleable and will never snap in normal service but can pull apart under tension. Our SE insisted on the spliced joists being bolted hard together for that reason, the builder had some "structural screws" that were supposedly good enough, but weren't allowed.

 

[DIYer Damo]

I’d never considered these issues so think I’ll play it safe and whack a few nails in to be safe.