Important Information for Choosing the Correct Tile Underlayment for a New Wall or Floor Tile Installation

Choosing the correct Tile underlayment is a very important step for starting your tiling project off right.

Tile requires a flat and stable surface, and especially when it comes to tiling a floor with ceramic or stone floor tiles.

If the underlayment isn't right for these floor tiles, you can easily find yourself routinely replacing cracked tiles.

Even when tiling a floor with vinyl floor tiles, you'll need a smooth flat ply-wood underlayment to lay your tiles to.

Vinyl floor tiles are very versitile and resilient but any imperfections in the floor underneath will show right through them.

When tiling a wall you can sometimes do the simple task of patching drywall or plaster, and then lay your wall tiles directly to it.

When Tiling A floor there are times when you can lay your tiles directly to the concrete or plywood subfloor,

You can tile over a slightly slanted floor, but not if the floor has lots of hills and valleys.

For these types of subfloors thinset alone won't do the trick of leveling them out, but you may be able to fix the problem by applying a floor leveling compound.

If you desire to use vinyl floor tiles or any other resilient tile, it is of major importance that the subfloor be smooth and level.

The reason for this is that Vinyl floor tiles as well as all other resilient tiles show all the imperfections found in the subfloor below. 

Tips for Tile Underlayments

*If your existing floor's underlayment is solid, you may be able to tile right over it.

*If the existing floor is not strong enough or the area will get wet, you'll do well by Installing the materials specially designed to support the tiles and in some cases to also withstand moisture

*Greenboard and Blueboard are special moisture resistant types of drywall tile underlayments,

They are no longer recommended for situations where there is a chance of water getting on the tiles.

It's better to use cement backerboard or fiberglass board instead.

*Plywood is always the perfect tile underlayment for cork, vinyl,laminate and parquet floor tiles.

*Ceramic and stone tiles can also be installed to ply wood, as long as the floor structure is solid and smooth and the tiles will not be getting very wet.

If in doubt simply use cement backerboard. it works perfect with ceramic and stone tiles no matter if the area will be wet or dry.

It's actually a better underlayment for them.

*There are certain tiling jobs where a plywood undelayment just isn't enough.

It doesn't matter if your tiling a floor or wall, if these areas will be exposed to water you'll definitely need a cement backerboard tile underlayment.

*If you start your tiling project by using the correct tile underlayment and the correct tile adhesive for holding your tiles to it, you are on the right path to a great tiling job. 

Ply wood Tile UnderLayment

Ply wood is the perfect underlayment for vinyl tile, cork, wood parquet, and laminate tiles and it's fairly easy to install.

You can even use a plywood underlayment for Ceramic and Stone tiles as long as you're installing them in a dry area. 

Go here for simple instructions for installing a plywood underlayment

Cement Backerboard Tile Under-Layment

Cement backerboard is the best tile underlayment for ceramic and stone floor tiles, and especially in areas that will be exposed to moisture such as bathroom, laundry room and basement floors.

It's also the perfect tile underlayment to use under wall tiles that will be exposed to water such as for bathroom showet tile or wall tiles for a tub surround. 

Go here for simple instructions for installing cement backerboard to floors. 

Go here for installing cement backeroad to showers and tub surrounds.

Go here for an example of installing backerboard to kitchen countertops. 

Repairing a Concrete Subfloor

Water is the worst enemy of a concrete subfloor, especially a concrete subfloor that is below grade.

These floors are very vulnerable, so you should never install floor tiles of any kind to a concrete subfloor until you fix the water problem and repair the concrete. 

Go here for simple instructions on repairing a concrete floor. 

Installing Drywall for Your New Wall Tile Installation

Drywall is also known by the names wallboard, or sheet rock. You can lay tiles over standard drywall, as long as it's in a dry location and the drywalls in fairly good condition.

If your drywall isn't you can do the simple task of patching or if needed installing drywall.

When installing drywall it gets screwed to the beams of your wall.

The task of installing drywall is fairly easy and it makes a nice smooth surface for painting, but more important to tilers for laying wall tiles. 

Go here for instructions for installing drywall


Extremely wet locations such as showers, tub surrounds, or even a floor substrate that may shift or crack, such as an old broken up concrete floor are the areas that call for the installation of a membrane. 

Sheet Membrane and painted membrane

Any wall or floor tile installation that will be subject to standing water, such tub surrounds or shower walls and floors should have sheet membrane installed.

There are a lot of high tech membrane sheets, but all you really need is a good old fashioned tar paper.

Painted Membrane should be used for sealing the joints between sheets of cement backerboard, in the case of tiling a shower or tub surround, 

Go here for a sample of how to apply a painted membrane and install sheet membrane to a tub surround or shower= shower tile

Isolation Membrane

Isolation membrane keeps the tiles separated from the surface below. This is generally because that surface is cracked and subject to movement, and this could damage the tiles.

There are a lot of high tech isolation membranes, but all you really need is a good old fashioned tar paper.

You lay the tar paper over the subfloor. You then lay galvanized welded wire, and a thick bed of thinset, and there you are with your perfect isolation membrane.

* An example of installing isolation membrane can be found above in repairing a concrete subfloor. 

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