Fixings for Tanalised Timber

Dunno, but BZP is not galvanised, or anything much like it. If it's a shed, it's not going to be permanently wet, I hope. What screws do you need for what purpose? If it's something like screwing the sides/ends to each other and the roof/floor, you could surely use stainless, or even brass, with some other cheap BZP or whatever for other purposes.

Why, they're not *that* expensive if you shop around a bit, what sorts of sizes and quantities do you want?

I've standardised on stainless screws for all outside work and almost everything else as well. It's only if I want something *very* strong that I consider anything else now.

My sheds have outlasted any non stainless screws I put in them when we first came here (22 years or so ago). I'm now replacing the rusty husks of non stainless screws I put in 15+ years ago. The stainless ones I have been using for the last 15 years or so are still perfect.

Apart from anything else it means you can dis-assemble things and re-use the screws! Admittedly there are some losses because stainless screws are rather less robust that non-stainless but I'd guess 90% or so are re-usable.

That was my thought and so I thought I would look up some prices. While they are ~3x the cost of equivalent cheap BZP screws some 5 x 50mm stainless on Toolsatan are £14 per 200. If you want your build to last it's a small price to pay.