It’s important to have a solid subfloor before installing a finished floor on top of it.
Subfloor under ceramic tile:
- Concrete Slab: If the concrete is clean and in good shape, you can use thin-set adhesive to glue tile directly to a concrete slab. Fill any holes or cracks in the slab with floor patch compound and allow to set before laying tile.
- Vinyl Flooring: You can use thin-set adhesive to tile directly over vinyl flooring as long as the vinyl is clean, in good condition, and glued securely to the subfloor under it.
- Plywood Subfloor: Glue and screw 1/2” cement backer board to plywood subfloors before tiling. Fill any seams in the backer board with thin-set and apply fiberglass tape before laying tile.
Subfloor under laminate flooring:
- Underlayment: Put down laminate underlayment material on the subfloor before laying laminate flooring.
- Wall Gap: Leave an expansion gap between laminate flooring and walls, as specified by the laminate manufacturer, to allowing for seasonal movement in the floor.
Watch this video to find out more.
- How to Level a Subfloor (video)
- Installing Tile Over a Wood Subfloor (article)
- Installing Cement Backerboard on a Wood Subfloor (video)
Danny Lipford: Hey, we love getting questions from viewers. And lately it’s all about flooring. And can you put a certain type of floor over an existing floor? And if you’ve got concrete like this, and you’re wanting to install some ceramic, all you need to do is make sure the slab is nice and clean. And if you have any little holes here and there, fill them with a floor patch compound and you’re ready to go.
One question we’ve gotten, “What if I have vinyl on the floor, and it’s in pretty good shape, can I then install ceramic over vinyl?” Absolutely. No problem at all. As long as the vinyl is glued securely to the slab.
Now, here’s another scenario – a wood subfloor. If you have a wood subfloor, “Can I install ceramic directly to it?” Absolutely not. You’ll have some flooring guys out there saying that it’s okay, but I guarantee you’ll end up with some cracks. Much better to do exactly this. First, this is half-inch cement backer board. You’ll want to put down an adhesive below it, then you’ll want to screw it with coated screws. Then, any seam that you have, you’ll want to put fiberglass mesh tape over it, and then use a thin-set adhesive to kind of smooth everything out. Then when you work hard and install all of your ceramic, it’ll be there for a long, long time.
Hey, another option. We talked earlier about wood, and wood’s beautiful. If you have a wood subfloor, you can nail it straight down there. But so many people are finding out about laminate floors and still being able to get that great wood look. So, you have either concrete or wood, what you’ll want to do first is use an underlayment.
Now, this is a really good underlayment. There’s a lot of different types of underlayments – some will be very, very thin. It’s a lot better, in my opinion, to step up to a better underlayment, because it’ll make for a much quieter floor, and you’ll get all of the vapor barrier that you need.
After that’s down then you can take various types of laminate floor, these things are great now, they don’t even require any glue, just click ’em together like this. Follow your instructions, make sure you don’t get it too close to the wall, because it does need to expand and contract a little bit. And in most cases, in less than one day you can have a nice looking laminate floor.