We tried screws and nails as we were testing everything. The only thing that didn't split it was glue but am unsure about using it on a cage so we dismissed it. If you nailed into the flat surface it was all fine it was just the edges that weren't and we couldn't think of a way around that so are going MDF instead.
8 Degus - Ranna, Kibeth, Forte, Forza, Pepper, Salt, Spice and Arthur. 4 Cats - Micah, Suki, Phoebe and Mogwai. 4 Chickens. 9 Fishies. 2 Dogs - Dave & Lily
If you drill first, then screws shouldn't split it, unless you are really close to an edge. You can make the pilot holes quite big to reduce the risk of splitting. You could also use angle brackets so that your screws are going in further away from the edge, and into the face of the sheet. You are always going to have problems if you are trying to fix into the edge of the plywood (or any other sheet material). Is this what you were having problems with, Listracian? If so, some brackets might be the answer?
I had a quick look at the plywood selection in Wickes yesterday. The birch stuff was only in 6mm, so not thick enough, the structural spruce stuff looked a bit knotty, so I would go for the 'exterior' grade stuff, it's nice and smooth, if that helps anyone.
I'd love to know a bit more about how well the adhesive vinyl tiles work? Can you fit them up to the edges quite well, and do they butt up to each other well? I'm concerned that wee might leak down the joins? Are they better than lino?
Beware with the plywood! We bought some to test for our cage, getting plywood and MDF and the plywood tended to split when nailing stuff into it because of the way it's made. We are going for MDF for that reason just because otherwise it might be a lot of money spent and possibly wasted! I don't know if it happens for everyone? I know nothing about wood and stuff but my boyfriend and his dad have always made stuff with wood and have all the funny wood cutting stuff... but they said the same about plywood which is why we tested it (I didn't believe them!) Apparently it's to do with how they layer the wood - but anyway thought I would put it out there are a warning, it may not always happen but it did to us!
The plywood for building the cage should be atleast half and inch thick. Anything thinner than this would split too often when using screws or nails. As deguconvert mentioned, using a strong wood glue is essential. People tend to underestimate how strong glue is once it dries. Having a nailgun also helps a lot when building a cage out of plywood.
Degus are not my whole life, but they make my life whole.