Q: How should you detail the edge of a tile floor where it meets a carpet?
A: Tom Meehan, co-author of Working With Tile (Taunton Press, 2011) and a second-generation tile installer from Harwich, Mass., responds: When I have a choice, I always opt to install tile before carpeting, for a number of reasons. First, I can install the tile on a straight line that is easy to bring the carpet up to. And because setting tile can be a messy job with mortar, water, and grout, tiling first keeps the mess away from the carpet. It’s much easier to sweep carpet crumbs off tile than it is to clean mortar out of the pile of a carpet.
Tiling Before Carpet
When the tile is to butt into carpet, I begin by drawing a straight line where I want the transition. I try to be mindful of exactly how and where the transition line between the carpet and the tile will be located. In the project shown in the photos below, the hallway carpet was to tuck under existing baseboard on either side of a tiled entry. So I drew the guideline for the tile at the edge of the wall rather than at the edge of baseboard, using a straightedge and a waterproof black marker to make the line.
When setting the tile, I comb the mortar straight back from the line, and then set the tiles with their outermost edges against a straightedge, in this case a 6-foot level. I make sure to scrape up any excess mortar or grout that oozes beyond the line. When the grout cures, the carpet layer can then position the tacking strip exactly where it needs to be to make an even transition between the two floors.
Tiling to Existing Carpet
If I need to tile up to carpet that has already been installed—at a doorway, for instance—I install the tile carefully to within about an inch of the carpet. Again, I’m careful not to get any mortar or grout on the carpet. To bridge the transition between the carpet and the tile, I fashion a T-shaped wooden strip that bridges the edge of the carpet and the edge of the tile (see illustration below). I make the strip from 1-by oak that I rip to 2 inches wide. I rabbet the edges about 3/8 inch deep on each side, leaving 1/4-inch-wide wings on the top. I round over the top edges and give the strip a couple of quick coats of poly.
To install the strip, I first remove the tackless strip, if it is in the way, and I fold the carpet flap from the threshold under itself, leaving a gap of about 1 1/2 inches between the tile and the carpet. Before folding the carpet, I apply a bead of construction adhesive to the underside of the flap so that the carpet will adhere to itself. After making the fold, I sharpen the crease by going over it with a hammer. Then it’s just a matter of applying construction adhesive to the strip and pressing it into place, overlapping the edges of both the tile and the carpet. I usually put weight on the strip to hold it in place while the adhesive cures—overnight, if possible.