Vinyl tiles on bathroom (toilet) floor, what underlay?

[HumptyDumptyBumpty]

I need to replace the cheap shitty vinyl in our toilet (separate to bathroom, I know, v old fashioned!) urgently. It's crumbling, and impossible to clean. Landlord is happy for me to do so. They won't replace, as it's 'cosmetic' rather than 'needed'...

I want to do vinyl tiles, as a) it's a tiny room, and b) I've never done it before, so don't want to risk buggering up vinyl sheet.

Currently the sheet vinyl is laid on floorboards directly, but I have read that I need a hardboard or plywood layer underneath tiles?

Problem is, I don't have the circular saw needed to cut to size, and around the pedestal and the random pipes. I have a normal saw, and a handsaw/hacksaw (the one with a blade across a space, rather than a solid blade).

So: can I use something else for underlay? Or can I get a sheet cut to a shape (including hole for pedestal)? I can't lay onto existing vinyl, as it's all lumpy, has buckled at one point, and has a bent over nail through it! Please help!

Hi,
Make a paper template, mark out on hardboard or 4mm ply, use a hook blade in a stanley knife to cut out, fix ply or hardboard at 6 inch centres with 3/4 inch ring shank nails. can be cut with normal straight blade in knife, but would need to be scored several times. (watch your fingers!)
Ideally thicker ply would be better but you would need more tools, the above would do a good enough job without costing a lot.

Ok, firstly I would buy a jigsaw as they're always useful. But the advice above is very good. Secondly, I would disconnect the toilet so I could lay the tiles under it. Where does the soil pipe go? If it's not into the floor, you could just turn the water off at the isolation valve, bail out the water and then disconnect the pipes and pop it out in the bathroom while you put down the ply and the tiles. It's much less tricky than you'd think.

Brilliant! Thank you. I shall get a hook blade for a Stanley knife and have a look at the soil pipe as well. Much appreciated.