Questions about building a shed, to do with wood, types of screws and membrane

[lozcozard]

But its screws into copper treated wood, and I read its the wood treatment that would corrode the screws, so bright zinc plated are OK? Online only says stainless steel or hot dipped galvanised.
Thanks

 

[Deleted member 174758]

A few miles from our house there is a 6ft high hit and miss fence made from pressure treated softwood which has withstood the Pennine winds, rain and weather for the last 20 years. It faces full on into the winds from the west with no shelter at all. Despite the first and two subsequent owners of the property being advised to treat the fence every 2 to 3 years with a preservative or oil, it has only been painted once - about 6 months after it was put up. It is still standing, although some of the nail heads are now showing signs of corrosion, so it will need some work doing on it at some point in the future. The fence was nailed together using bright steel full head nails. I know that fence because I built it in the dead of winter and it was just so cold and/or wet every day. That treated timbers accellerate corrosion is true, but nails and screws don't fall apart in 6 months unless subjected to a far more highly corrosive environment than the British weather and some Tanalith, especially (which is key) if protected by a coat of paint, creosote or decking oil. If you were taking your shed to sea, I would suggest bronze or stainless fixings, but you aren't, are you?

 

[lozcozard]

No I am not, and I cant stand stainless steel screws. Not only more expensive but they're really soft, the heads just wear right down. would bright zinc screws cost less and be stronger?

 

[Deleted member 174758]

Yes and yes

 

[Ryler]

e but they're really soft, the heads just wear right down.

And they wring off in a second.

 

[ray.birch]

So as a bit of background, I often like to over-engineer anything that I've put my mind to building, so similarly when building my shed, went with a breathable membrane and over-specced the timber several times over).

I'd always go for treated timber - it's not a huge amount more, and it just means there are fewer concerns over the years with respect to rot etc.

Re: fixings, I ended up using Spax BZP screws almost exclusively - yes they're not the cheapest by a long shot, but just a pleasure to use. For fixing the cladding however, I did use S/S Tongue-Tite torx screws. I have to be honest, part of the reason was that I just *like* the aesthetics of these screws, and they are also less prone to splitting the wood. It does also mean that I don't have to worry about rust, which, whilst I wasn't bothered in the slightest about structural integrity (I think the shed will be here long after we've moved home!), it does mean that 2 years on the fixings are still as visually pleasing as they were the day they went in.

Just one thing to query - you said you put cladding over the top of a membrane - did you leave space between the cladding and the membrane?