We watched some pros installing sheet vinyl flooring.
First make sure that there are no cracks between boards in the sub-floor or they will show through the vinyl eventually. Do not fill the cracks with any kind of plaster product, it will break up under the vinyl and create bumps. Use a cement-based floor sealer. It will look grey.
If it is a really complicated shape, tape together several cardboard boxes to create a perfect template. Then take both the vinyl sheet and the template to a large area, like the basement floor, and cut the vinyl to match the template.
If it is not too complicated you can cut it to fit as you go. Lay a carpenter's square flat on the vinyl flooring and push it into the wall/floor joint. Then use the metal square as a guide for your knife. It will prevent you from cutting towards the centre of the floor, something easy to do without a guide.
How much glue you put on the floor depends on the type of vinyl you use. Some are specifically designed to shrink, pulling themselves tight, so they have to be better attached all around. Follow the manufacturer?s instructions to the letter when it comes to attachment. Always glue the entire area under the refrigerator to keep the vinyl from shifting and catching when you move the fridge.
Joints are hard to do and if you have to have one in the middle of the room, leave it to a pro, or at least get the special tools and sealers that are necessary to do a good job.
The installers in the show work for G.E. Schnier Co. in Toronto and were installing Armstrong flooring.