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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Carpentry Questions >> Outdoor screws https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1250073199 Message started by CWatters on Aug 12^th, 2009, 11:33am

Title: Outdoor screws
Post by CWatters on Aug 12^th, 2009, 11:33am

I went looking for some 100mm/4" outdoor screws today but was surprised not to find any in local builders merchants. On the web found that Screwfix have stainless steel and BnQ have "Dachrotised" screws.

Last time I used stainless screws I had some problems with them shearing unless I drill deep pilot holes. How do Dachrotised screws compare with say green organic coated deck screws?

I'll be using them to fix battens to an outbuilding prior to cladding with weatherboard (possibly oak boards). I'll probably have to use SS for the boards but what about Dachrotised screws for the battens? Don't want them rusting and failing in a few years.

Title: Re: Outdoor screws
Post by Zambezi on Aug 12^th, 2009, 1:09pm

I use the SF turbo ultra SS screws for small exterior stuff or decking screws for bigger things. I have sheared a few of the standard SS screws but I can't remember shearing a Turbo Ultra?

Title: Re: Outdoor screws
Post by woodsmith on Aug 12^th, 2009, 5:35pm

I've sheared lots of the turbo ultras ::), although you may well be OK with a 6x110mm. They are generally fine in softwood, it is oak that snaps them even when pre drilled.

The slotted stainless are good and I have never had one shear, but they are a pain to use compared to posidrive; I bought a load of Spax stainless, I think from SF, and they have been great, no shearing and drive well. SF also had some square drive stainless and they were also good.

But if the battens are behind the cladding they will not get any weather and at a pinch you would probably be OK with a quality, Spax or Reiser, steel screw.

Title: Re: Outdoor screws
Post by Zambezi on Aug 13^th, 2009, 8:46am

My customers can barely afford pine so I have not tried them in oak, the longest I have used are 30mm, so not a lot to shear.

I might get some of the Spax SS screws when I next do some exterior work. One day...

Title: Re: Outdoor screws
Post by CWatters on Aug 14^th, 2009, 10:00am

SF don't have 100mm SS Spax but I found them on the web - tad expensive at £34 per 100. I think I'll try a 100 pack of the Turbo Ultras at £17 and see how they go.

Planners want me to use a dark stain on the weatherboarding so can't decide if I should buy prepainted softwood weatherboarding or take the risk and use oak. Anyone know if green oak takes wood stains (eg Cuprinol or Ronseal General purpose)?

If I go with the oak I'll have to decide if I have the patience to plug the screw heads. Does look good...

http://www.taylorsgardenbuildings.co.uk/oak-clad-studio/plugged-oak.jpg

Title: Re: Outdoor screws
Post by Joiner on Aug 14^th, 2009, 5:30pm

It'll take the stain and look good.

Title: Re: Outdoor screws
Post by CWatters on Aug 14^th, 2009, 5:39pm

Great thanks. I plan to use a lighter stain than they really want and hope they don't drop in to check on me.

I picked up a box of 100 Turbo Ultras and ran most of them this afternoon before the battery went flat on me. No problems at all. I like the big heads and the lack of coating in the cross cut makes them a lot easier to drive than coated steel. Will be back to SF to pick up enough to finish the battening tomorrow.

Title: Re: Outdoor screws
Post by woodsmith on Aug 14^th, 2009, 6:02pm

Plugs on untreated wood outdoors don't stay in place long, I'd use stainless ringshank nails and just counterbore enough so they sit flush. No plugs so a lot quicker and neat too, I have a similar job to do when the weather changes and I've had to buy stainless ringshank nails on the net, as I couldn't source them locally.

I wouldn't stain it either if I could get away with it, I''d just keep telling them I was going to do it when the weather was cooler/hotter/ less wet/etc.. ;)