Before you tackle your next DIY project, be sure to take a look at Mike Holmes' family's advice on using thin-set mortar to install tile and stone.

Step 3: Mix only as much thinset mortar as you can cover with tile in about 15 to 20 minutes for the best results. Never add more water to thinset that's getting hard in the bucket.

Before you tile, smooth over the drywall with premixed thinset mortar and a trowel, forcing it into any low spots. Allow 30 minutes for it to dry. Plan the layout.

Spread thinset mortar in a sweeping motion with the smooth and straight back edge of the trowel. However, comb the mortar out in straight lines with the trowel’s notched sides.

Use a 1/4 by 1/4 notched trowel to spread the thinset mortar you’ll use to bond the tile to the new mortar. Spread it evenly and press the tile lightly into the thinset.

Thinset is a mortar that comes in varying grades, each with its own specific combination of cement, fine sand, and a polymer which allows the product to retain water.

Exterior tile is installed on concrete using Portland cement. Modern tile setters and manufacturers call it thinset mortar. In its most basic form, it’s just Portland cement and fine silica sand.

Mastic is not as strong as thinset mortar, however, and not as water-resistant. If you want to use thinset, keep tile in place with spacers, nails, or tape.