How to Create a Shower Curb

Measure the distance between the walls of the shower to determine the length of the floor curb. Measure and cut two identical lengths of 2-inch-by-4-inch lumber to this length. Position one board directly above the other and nail them together. Set the boards at the foot of the shower, between the walls. Nail the boards to secure them to the floor.

Cut a piece of metal lath large enough to cover the 2-inch-by-4-inch lumber, using tin snips. Spread it over the boards, nailing it only to the front.

Add mortar to a 5-gallon plastic bucket. Slowly pour water into the mortar and mix with a trowel until it reaches a workable consistency.

Scoop some mortar from the bucket and apply it over the 2-inch-by-4-inch block, spreading it evenly over the lath. Continue spreading mortar over the lumber until it forms a 1-inch-thick layer.

Position the straightedge directly above the mortar on the lumber. Align it so its upper edge extends the front of the lumber block by 3/4 inch. Press the straightedge down firmly on the mortar to create suction.

Pack mortar into the 3/4-inch gap along the front of the lumber block. Level the mortar with the trowel and continue to pack in more until you have filled the entire length under the straightedge.

Position the butt of a flat trowel flush against the floor and slowly extend it along the mortared section to scrape off the excess. Press the straightedge down with one hand while you hold the trowel with the other. This ensures the side of the curb is plumb.

Slide the straightedge over to the other side of the curb, or its back, and repeat the process so its face is flush. Carefully remove the straightedge from the top of the lumber and leave the mortar to dry for an hour.

Tile the curb when the mortar dries, using the same tiles as the bathroom flooring. Install the tiles on the front and back of the curb first. Spread a 1/4-inch-thick layer of mortar over the back of a tile with a notched trowel before setting it over the curb.