Im doing a garage conversion and have decided to lay a floating floor. So I have laid the dpm and now i have laid 100mm celotex on top off it. My problem is it feels a bit bouncy at the miniute is this ok?will the 18mm flooring takes the bounce away? also i have a few gaps around some of the edges about an inch at max in some parts do i fill these with anything?expanding foam or off cuts? i still have to tap up all the joins in the insulation yet with celotex tape but wanted to solve the bouncyness first. any help would be great?