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Surface Preparation

Can I set tile directly over a plywood subfloor?

Yes, you can set over a subfloor made of APA exterior grade plywood that is built to tile industry standards. However, plywood is hard to bond to, and it is not a stable surface as it will expand and contract. Because of the difficulty of bonding, a special polymer-modified mortar that meets ANSI A118.11 standards is required. As a superior alternative to bonding directly to plywood, we recommend WonderBoard. The backerboard is installed directly over the plywood subfloor and the tile is bonded to it. Cement backerboards are easier to bond to and provide a more stable surface.

Why and when should I use a cement backerboard?

Cement backerboards such as WonderBoard are made of cement to offer a very stable surface that won’t warp or deteriorate. Cement mortar bonds extremely well to cement surfaces, so you can be assured of a superior bond. Backerboards are impervious to water damage even when exposed to continuous moisture, so they can be safely used in wet area installations. Many materials such as plywood, drywall and even water-resistant drywall can be damaged and will deteriorate when exposed to continuous moisture. Backerboards are also a superior alternative to bonding directly to a plywood subfloor.  Plywood is not a stable surface and will expand and contract with climate changes. Backerboards provide a more stable surface on which to bond tile.

When should I use ¼” backerboard instead of ½” backerboard?

Backerboards come in two thicknesses: ¼” and ½”. ¼” backerboards are used for floor and countertop installations. They reduce subfloor modifications to adjacent floors, thresholds, carpet and cabinets. ½” backerboards can also be used on floors and countertops but can also be used for countertops, as well as on walls. They line up with surrounding ½” drywall installations without the need for shims or spacers on wall studs.

Do I need to use fiberglass mesh joint tape when installing Wonderboard?

Only on wall installations where unwrapped panel edges meet and in corners. It is not necessary to tape joint panels when doing floor installations.

Can I bond tile directly to cutback adhesive?

Although not an ideal situation, you can bond to cutback adhesive over concrete slabs. But the cutback must be non-water soluble and properly prepared. The remaining residue must be almost transparent and no thicker than a coat of paint. Use caution during preparation, as adhesives may contain asbestos fibers and sanding can result in harmful dust.

Can I bond tile directly over sheet vinyl flooring?

Yes. The sheet vinyl must be non-cushion backed, well bonded to the floor, clean and free of all contaminants that would prevent a good bond. We recommend roughing up the floor by sanding. However, under no circumstances should you sand flooring if you suspect it contains asbestos, as harmful dust will result. 

Do I need thin-set mortar under WonderBoard?

Yes, it acts as a filler and leveling bed for the cement board.

Installation

When should a thin-set mortar be used as opposed to a ceramic tile adhesive?

Most ceramic tile adhesives have very high bond strengths in dry areas, which makes them excellent for drywall installations. Yet when adhesives are exposed to water, their shear strengths are dramatically reduced. Thin-set mortar bond strengths are less affected by water. As an example, the dry shear strength for OmniGrip is 760 psi and the wet shear is 145 psi. This is why ANSI recommends intermittent water exposure only and interior use for adhesives.

Ceramic tile adhesives can take a considerable time to dry, usually a minimum of 24 hours before applying grout. When applying tile to dense surfaces such as existing ceramic tile, to impervious or vitreous tile such as porcelain, in high humidity, when temperature is below 60°F, or when setting tile over 6” x 6” drying time can be greatly extended beyond 24 hours. Thin-set mortars are preferred in these situations, although ceramic tile adhesives will perform.

Manufacturers typically recommend adhesives more for wall installations; thin-set mortars are preferred for floor installations.

All of Custom’s ceramic tile adhesives can be used to set gauged slate, marble and granite tile. All stone must be gauged tile up to 3/8” thick (no irregular backing). Do not use ceramic tile adhesives to set moisture-sensitive, light translucent or resin-backed stone.

What’s the difference between an adhesive and a mastic?

Mastic is a viscous material that is commonly used as a gap filler or sealant in the roofing industry. The term “mastic” is also applied to other similar construction industry products, such as pre-mixed ceramic tile adhesives. The American National Standard Specifications for the Installation of Ceramic Tile (ANSI) defines mastics as “organic adhesives” to distinguish them from thin-set mortars, which are inorganic adhesives. An organic adhesive uses a polymer as the bonding agent, whereas an inorganic adhesive uses cement. Generally, "adhesive" and "mastic" are interchangeable terms in the tile industry.

When do I need to use an additive with a thin-set mortar?

There are two basic types of mortars: polymer-modified mortars and unmodified mortars. Polymer-modified mortars have higher bond strengths and are better than unmodified mortars for use in wet areas. The polymer (or latex additive) is already in the powder, so you only have to add water and mix. Unmodified mortars are adequate for basic tile jobs, such as a residential floor over concrete or a wall tile job when setting ceramic tile. Only water is required for these types of installations. For more demanding installations, a polymer-modified mortar is required. You can use a mortar that is already polymer-modified (latex is in the powder) or an unmodified mortar and a liquid latex additive that is used in place of the water requirement. Installations requiring a polymer-modified mortar are when setting porcelain tile or large tile over 12” x 12”, in wet areas, high traffic areas, exterior installations, surfaces that could be subject to minor movement, installing tile over exterior grade plywood, vinyl flooring, plastic laminates or other hard to bond surfaces or setting tile over a waterproof membrane.

What's the difference between ANSI A118.1, A118.4 and A118.11 mortars?

ANSI (American Standard Specifications for the Installation of Ceramic Tile) is an organization that sets-up performance standards for mortars designed to set ceramic tile. A mortar meeting A118.1 is an unmodified, dryset mortar that doesn’t contain a polymer. Unmodified mortars are adequate for basic tile jobs such as a residential floor over concrete or a wall tile job when setting ceramic tile. For more demanding installations a polymer-modified mortar is required. Polymer-modified mortars meet ANSI A118.4 standards. You can use a mortar that is already polymer-modified (latex is in the powder) or an unmodified mortar and a liquid latex additive that is used in place of the water requirement. Installations requiring a polymer-modified mortar are when setting porcelain tile or large tile over 12” x 12”, in wet areas, high traffic areas, exterior installations, commercial installations, surfaces that could be subject to minor movement, installing tile over vinyl flooring, plastic laminates or other hard to bond surfaces or setting tile over a waterproof membrane. Installing tile directly over exterior grade plywood requires a mortar with special bonding capabilities, so these installations require a mortar that meets A118.11 standards.

Grouting

Do I have to use a sealer on my grout?

No, you don’t have to use a sealer, but it is highly recommended. Grout is very porous and is prone to staining if not sealed. Sealing helps to prevent stains and dirt from penetrating into the grout and makes it easier to clean. A sealer also helps to prevent mold and mildew growth.

Can I use epoxy grout in pool installations?

Yes. However, epoxy is temperature sensitive. 100% Solids Epoxy Grout is easiest to apply when temperatures are between 70° F and 85° F (21° C and 29° C). Lower temperatures will cause the epoxy to become stiff and more difficult to work, and will extend initial set time. Higher temperatures will cause the epoxy to become more fluid and will accelerate the set time. It is not recommended for installations exposed to continuous temperatures above 160° F (71° C). When used on exterior installations, color variations may occur over time, especially with lighter shades.

Care & Maintenance

Why do I need to seal my tile installation?

Sealing is a critical step in completing your grout, tile or natural stone surfaces to maintain the “like-new” appearance for many years. The cost of sealing is minor compared to the cost of repairing or even replacing a marble, stone or tile surface that has been stained or damaged. Sealers, such as those from the TileLab line, can:

• Enhance the finish and color of stone
• Protect against unsightly stains
• Minimize the appearance of abrasions
• Seal porous surfaces to inhibit the growth of mold and mildew

All surfaces should be sealed initially with SurfaceGard Penetrating Sealer, a product that contains Teflon to repel stains and is guaranteed to protect surfaces for 20 years or more.

Test sealed surfaces for effectiveness every two years by sprinkling water on the surface at various locations. If it penetrates, renew by applying one coat of sealer.

Are all sealers the same?

Water-based stains such as wine or juice may etch stone surfaces. Oil-based stains such as salad dressing or grease are hard to prevent and hard to remove. All TileLab sealers are effective against both water-based and oil-based stains. Silicone sealers are not typically effective against oil-based stains.

What is the difference between a penetrating sealer and a finishing sealer?

Penetrating sealers act as an invisible barrier to stains by penetrating the surface of grout and porous tile. TileLab’s Surface Guard and Grout Sealer are penetrating sealers that provide a natural look for any unglazed tile or grout.

Finishing sealers provide a protective sealer on top of grout or porous tile to resist stains, dirt and grease. TileLab’s loss or MatteSealer & Finish and Stone Gloss Polish offer these benefits. Surface sealing is not recommended for marble, limestone or granite.

Should I seal marble and travertine?

These calcium-based stone types are very porous, which makes leaving them very susceptible to acidic stains. Many food products, such as lemon, wine, tomato sauce and coffee, are acidic. Definitely seal marble and travertine after installation.

Can sealing reduce mold and mildew?

Sealing porous surfaces prevents the material that mold and mildew feed on, like soap scum, from penetrating into the surface. Sealing the surface periodically, along with regular cleaning, can prevent build-up and inhibit the growth of mold and mildew. The ideal solution is to use One Step Cleaner and Resealer every day, because it contains a small amount of SurfaceGard to reseal your surface with each use. Unlike many household cleaners, OneStep does not rely on harsh acids or abrasives that can damage stone, grout or tile.

How soon after my tile is installed can I seal it?

You should wait 48 – 72 hours after your installation to seal it. This will ensure that all moisture is removed from the installation so the sealer is not diluted.

I have a wax or finish sealer on top of my tile or stone - can I seal over it?

Before applying another sealer, use TileLab Heavy - Duty Cleaner & Stripper  to remove acrylic or wax finishes. It’s concentrated for tough cleaning and is safe for grout, tile or stone.

Are all cleaners the same?

Many ordinary household cleaners contain harmful abrasives or acids which will damage stone, grout and porous tile surfaces. TileLab cleaners are specifically formulated to be safe for all stone, grout and tile surfaces. The ideal solution is to use One Step Cleaner and Resealer  every day, because it contains a small amount of SurfaceGard to reseal your surface with each use.