Adding a special latex additive to thin-set tile mortar makes the mortar up to 3 times harder and increases its flexibility. This is especially important when setting tiles in bathrooms or other places that will be subjected to extremes of temperature and moisture. A latex additive should be added to thin-set mortar whenever the mortar will be used to bond tiles or other materials to plywood or wallboard.
Things You'll Need
- Thin-set mortar
- Latex additive
- Plastic mixing container
- Variable-speed electric drill with mixing tool
- Dust mask
- Eye protection
Pour 25 pounds of powdered thin-set mortar into a large plastic container. (Be sure to wear a dust mask and eye protection.)
Slowly add 1 gal of liquid latex additive. Mix at low-speed (no higher than 300 r.p.m.), using a mixing tool attached to a variable-speed electric drill. Continue until the mixture is the consistency of cake batter. (This should take approximately 5 minutes). No water should be added.
Allow the mortar to set for 10 minutes, and then mix for 2 minutes more. If the mixture is stiffer than cake batter, add a small amount of additional latex. If the mixture is too thin, add a small amount of additional mortar. When adding ingredients, use small amounts and work slowly.
Once your mixture is the consistency of cake batter and thoroughly mixed, it is ready to be used. The mortar should remain usable for approximately 4 hours, although you may need to add a small amount of latex after the first hour.
Tips & Warnings
- Expect coverage of approximately 70 to 90 square feet with a 1/4 inch trowel and coverage of approximately 55 to 65 feet with a 1/4 X 3/8 trowel.
- Clean the receiving surface thoroughly before applying mortar.
- Do not apply mortar if the surface to be tiled is colder than 40 degrees F.
- Wear a dust mask when working with the powdered mortar.
- Wear eye protection when mixing.