FAQs

The reason for so many trowel types is that there are so many flooring types. Think about what is being installed: Everything from thin vinyl sheet to 3/4" solid hardwood flooring. Each flooring material has unique properties. For example, a thin vinyl sheet is very flexible, so you don’t want heavy trowel notches on the floor as they will show through to the surface of the vinyl (an effect called “telegraphing”). So for thin resilient flooring, we typically recommend very finely notched towels. Wood flooring, on the other hand, has a variable backing structure. Some can be smooth and others grooved or cross-cut, so you need a trowel notch that can lift and shape the adhesive in such a way that it comes into solid contact with the flooring material. Further, wood flooring is very rigid and does not bend or conform to the subfloor. Therefore you need to use a trowel notch that accommodates for subfloor flatness and still brings the adhesive into contact with the back of the flooring. Using a thin-notched trowel for this would not allow for proper adhesive transfer. The same thing is true of broadloom carpet. Typically broadloom carpet has a rough-textured backing. In order to get proper performance out of a carpet installation, you need to make sure that the adhesive gets into this texture and that is why this application includes recommended trowel notches that create high ridges. In summary, smooth-backed flooring materials are typically installed using finely notched trowels while texture-backed materials get installed with larger-notch trowels.

New cement board will often come with a fine dust on the surface of the board. So, it is very important to clean the surface of the cement board and to allow the surface to dry before applying Mapelastic AquaDefense. Usually, wiping the cement board with a damp (not wet) sponge will effectively remove the dust.

Ready-to-use tile adhesives such as MAPEI's Type 1 and Premium Mortar for tile and stone require a porous substrate to cure properly. They should not be installed over a waterproofing membrane.

The answer to this question depends on what substrate you are working over. If you are installing adhesives over soft surfaces like plywood, then a trowel can last quite a while. If you are installing over a concrete or hard, abrasive surface, then a trowel may last about 2,000 square feet before the notches wear down. An installer may think that this is a good thing because his coverage will get better per gallon of adhesive, but in the end this is not a good situation as there may not be enough adhesive on the floor for proper bonding. Some trowels may last longer, but this is always something to check before getting started on any given flooring project: Make sure that your trowel is in good condition and will deliver the right amount of adhesive required for the project.

It is best to seal all porous stone before grouting the floor, and again after the grout has fully cured.

There are many causes for cracking in concrete. Concrete goes through many changes as it hydrates or hardens. Allowing the concrete to harden and achieve strength before these stresses arise will eliminate a large portion of these cracks. Proper curing, a good mix design, use of shrinkage-reducing admixtures and the addition of fibers are all good ways to help minimize some types of cracking.

When applying MAPEI's Mapelastic AquaDefense, it is important to allow it to dry in between coats. It is also important to avoid applying Mapelastic AquaDefense too thick. When applying Mapelastic AquaDefense over a mud bed, the mud bed must be dry before application. After using MAPEI's 4 to 1 Mud Bed Mix, the area should be allowed to cure for at least 24 hours per inch (centimeter) plus one day before application of Mapelastic AquaDefense. For example, if the mud bed is at 2" (5 cm) depth at its highest level, then you must wait three days before the application of Mapelastic AquaDefense. Curing time is based on 73°F (23°C). Cooler temperatures will require longer curing times. If your project is on a fast track, consider Planislope RS mortar, which can receive waterproofing in a matter of hours.

It is important for cement board (and fiber cement board) to be installed in strict accordance with the written instructions of the board manufacturer. This typically includes taping the corners and seams with mesh tape and covering the tape with a polymer-modified, cement-based tile mortar. MAPEI's Mapelastic AquaDefense should not be used to replace this critical step or bridge the gaps between cement board.

Regular cleaning is recommended, but the frequency depends on the usage in the area. For most installations and applications, the use of an appropriate cleaner, such as MAPEI's UltraCare Concentrated Tile & Grout Cleaner for floors, or UltraCare Everyday Stone, Tile & Grout Cleaner; UltraCare Everyday Stone Clean & Polish; and UltraCare Everyday Stone & Grout Cleaner & Resealer for countertops and backsplashes, is recommended routine maintenance.

Open time, sometimes called flash time, describes the amount of time that we want the freshly troweled adhesive to remain open to the elements before you start installing floor covering. There is a good reason why open time needs to be followed: Many water-based adhesives need a little time to start evaporating and letting some of the water out before you start installing flooring. Moisture-curing adhesives need to be exposed to atmospheric humidity to get the reaction started. Again, if you start installing before allowing for the recommended open or flash time, you run the risk of a delayed curing time, which can lead to placement problems and long-term performance issues.

Concrete can be placed in a wide range of ambient conditions. ACI guidelines explain the range of these conditions. Avoid placing concrete below 40°F or above 120°F without proper protective measures. Also avoid windy conditions without a wind break as this will expose the fresh concrete to premature surface drying, which can lead to cracking or a weakened surface that is prone to “dusting” and discoloration.

MAPEI's Keracolor U grout is unsanded. So, it's a great choice for grouting most installations of glossy wall tile. Other good options are Ultracolor Plus FA grout and Ultracolor Plus Max grout. When grouting installations of antique or handmade wall tile, it is recommended to build a mockup (sample board) or, at the very least, test these products in an inconspicuous area before grouting.