I am planning on laying vinyl sheet flooring in my kitchen floor. Can I use cement backer board as an underlayment.
if the backer board is down already then you can use it, all you need to do is skim over it with a cement patch called a feather finish, it will fill in all the imperfections and smooth it out for a flawless sub floor.
I'm a tiler and a Hardwood installer. Backer board is specifically used for tile. The board is designed to created a strong and rigid bond to the subfloor. There's always movement in a structure and if you skip backerboard then your tile moves with the natural flexing of the house causing cracking in the tile and grout. Viny is flexible so all you need to do is to remove existing flooring and lay right on the subfloor.
Cementitious Backer Board
Cement backer board is for use under tile. I have not seen anyone try to put vinyl over it. I would avoid doing this if I were you. 1/4 luan plywood is common for use underneath vinyl flooring. It provides a smooth, uniform surface to work with.
