First things first. If you are installing a nail-down or engineered floating floor, the manufacturer will usually require some type of underlayment to smooth out the subfloor, protect it from moisture or to help deaden sound.
All flooring manufacturers of hardwood, tile, bamboo, cork, linoleum, vinyl, or carpet require a flat, smooth, and level subfloor. This can require some serious prep work, especially if you live in an older home.
If your subfloor is made of old pine boards with big gaps in between them or sagging, sloping composite wood sheeting you will most surely need a new underlayment made of structural plywood, cement board or OSB to level out the subfloor. These structural underlayments are critical to the performance and longevity of the flooring. These will typically be provided and installed by your flooring contractor prior to the installation of your flooring.
Another type of underlayment is applied directly over concrete subfloors, plywood subfloor, or plywood underlayment. These act as moisture mitigators, crack isolators, and/or thermal and acoustical barriers. These come in a variety of forms from cork, to cement board to wool or recycled content and plastic membranes.
Properly installed, these types of underlayment will help prevent the intrusion of moisture which can cause problems like mold, mildew, warping, buckling, and cracking. It can provide extra comfort underfoot, reduce noise and prevent the cold from transferring into your floor from below. In short, it will extend the life of your floor and keep it looking good. This is why manufacturers require them. Each company has their own recommendation and it must be followed to the letter for warranty purposes.
We believe everyone deserves to live in a toxic-free environment. To that end, we have spent decades reviewing safety data sheets and testing products to cut through any greenwashing so we can bring you the safest building products possible.
Our selection of flooring underlayment includes vapor barriers made from recycled and natural materials that are non-toxic and odor-free. You will find options here suitable for floating floors, nail down or engineered hardwood floors, and bamboo floors. If you have cork, Marmoleum, or carpeting, we’ve got you covered too. We also carry waterproofing and crack isolation membranes to protect stone and tile floors as well as waterproof membranes for shower walls and floors.
This page was written by Joel Hirshberg