I did a bathroom about 6 months ago inc ply. The vinyl was quite thin and a little bumpy so I put some double sided tape in some areas but about...
Very nice. 3 weeks on the same job would drive me nuts
I use a electric plane does the job nicely
I don't think so. If you really must weld same day mark a line and leave a few mm either side then weld. Obviously it's not the correct way...