Installing a Marble Threshold on a Carpet Floor

What You'll Need
Marble threshold
Carpet knife
Carpet adhesive
Tile wet saw
Backer board
Notched trowel
Granite thinset
Putty knife

An attractive marble threshold is often the most eye-pleasing and the most practical method of making the transition from the flooring of one room to a different type of flooring of a separate room. Although marble may be a more expensive threshold, it is one that can be durable and colorful.

To install such a threshold separating two carpeted floors, or separating a carpeted floor from one that is tile or hardwood, you will need to follow the instructions below.

Step 1 - Choose Your Marble Threshold

You'll have a variety of marble thresholds. Choose the color and size that works best for you. Most home improvement stores stock one that will suit your needs. Before choosing one of them, measure the length and width of the threshold you'll be installing. If you are unable to purchase one that fits your size needs, buy one that is large enough for you to cut it to fit.

Step 2 - Prepare Your Carpet for a Marble Threshold Installation

Measure the threshold you'll be installing. If you have purchased one that fits the space you'll be installing it in, measure its length and width. If you'll be cutting your new threshold to fit, measure it after you've cut it. Then, use a piece of chalk and a straight edge to mark the measurements of your threshold on the carpet you'll be preparing.

You should have two parallel lines on your carpet, each separated from the other by the same distance as the width of your new marble threshold. With a carpet knife, cut completely through the carpet along each of these two lines. If you have carpet pad beneath the carpet, cut through it at the same lines. Then, remove the carpet piece and padding piece you've cut out. Apply carpet sealer to these two edges to prevent their fraying. Pull back the edge of each remaining carpet and remove it.

Step 3 - Set Your Marble Threshold in Place

If you're installing your threshold on a concrete surface, you will need to clean all dirt, dust, or debris from the surface with a vacuum cleaner. For glue residue that may be built up on the surface, use a putty knife or chisel to loosen the residue, then vacuum it up. Once the surface is clean, use a notched trowel and apply a thin coat of granite thinset on the concrete surface.

Put the threshold into place on the thinset, applying downward pressure and working the threshold in a somewhat circular motion to seat it on the thinset. When the thinset has set for 24 hours, you can then allow light traffic on it. If you are installing the threshold onto a wood surface, lay down a backer board first before applying your adhesive. This will provide your marble threshold with a more secure substrate on which to glue it.