We’re back for another update with general contractor Joe Bianco and the triple bathroom remodel. Joe has brought in Jim and Rich from Diamond Tile to tile all the bathrooms, and last week I shared how they poured the shower pans. Today’s post will back-track a bit to show you how Jim and Rich installed the concrete board, set guides for installing tile and started laying tile.

A lot of contractors use Durock for tile underlayment because it’s lighter and easier to work with than traditional concrete board. Jim and Rich used it on all the floors and walls.

Pro-Tip: Durock features a smooth side and a textured side. The textured surface provides a better surface for bonding and reduces tile slip with mortar applications.

It’s a common mistake to think that nailing or screwing the Durock over the subfloor is sufficient. However, the proper way to lay Durock is to put down a bed of thinset and lay the Durock overtop. Jim and Rich used Mapei Ultraflex 2 which is a polymer modified thinset.

Jim used a 1/4″ notched trowel to spread the thinset while Rich made any necessary cuts.

After each board was laid, Rich drove roofing nails about every 6″ to ensure good adhesion while the thinset dried. Roofing nails are ideal because they can be driven below the surface and they have a broad, flat head. Just like with drywall, the nails are only a temporary anchor. The thinset is what really holds the Durock in place.

The guys used a grinder to make cutouts for the toilet, shower controls, pipes and everything else. They also staggered the joints, placing cut edges around the perimeter and butting factory edges together.

In the showers, the guys were careful not to put nails within 4″ of the floor to prevent compromising the waterproof membrane.

Both tubs needed to be installed before the Durock, and they were both set in a bed of mortar. This ensures the tub is well supported so that you don’t feel any “soft spots”, and it distributes the weight across a bigger area.

Here’s a look at the master bathroom tub.

It was important that the lip of the tub have a gap because it’s not designed to support weight, and Jim and Rich needed to be able to slide tile underneath.

Jim did the two shower pans after all the Durock was installed.

Mr. and Mrs. Homeowner have requested the floors be tiled at a 45° angle, and it was cool to see Jim and Rich create the guides. First, they determined a layout that eliminated small pieces around the perimeter and ensured that the most visible areas had full and half-sized tiles. It was by chance that this layout also centered a half tile on the doorway.

To create the guides, Jim determined the center of the doorway and struck a perpendicular line. Next, measuring off the threshold, he found the location for the first tile and set it on the line, marking the corners on the Durock.

Jim used those marks and a square to begin creating the rest of the diagonal guides.

Each guideline was spaced at 23-7/8″ which is the measurement of two of these specific tiles and two joints.

Taking the time to set the guides enabled Jim and Rich to precut all the tiles, ultimately completing the job faster.

Pro-Tip: Tile is manufactured in batches, and to ensure the most consistent coloring, purchase tile from the same batch number or consecutive batch numbers.

To make curved cuts, Rich used a wet saw to cut the edge of the tile and cut slots that are easily removed with a pair of nippers.

In this way Jim and Rich set out the entire floor before spreading any thinset, and they were able to make cuts that leave little room for error.