[![enter image description here](https://i.stack.imgur.com/JjlXX.jpg)](https://i.stack.imgur.com/JjlXX.jpg)

I plan to put some cushion vinyl over my corridor carpet. I will be using proper cut sheets and not just off cuts as shown in the picture. Later on I will pull the carpet out from underneath the vinyl and glue it down.

I know this is not the most professional way but I need to do it now as the carpet is making me sick and I don’t have time to place boards then glue vinyl on right now. I know there will be bubbling in the meantime.

My questions are: 

1. if I cut the vinyl to shape while it is on the carpet, when I remove the carpet can I expect the vinyl to fit nicely or might a gap develop in which case how much extra sheet should I keep on the edges?
2. In order to cut the vinyl to shape, if I place the carpet on top of the vinyl as a template then draw the shape and cut it out, can I get a good fit or will this not work, if so why?

Thanks