The key is carpet-seam tape with adhesive on one side. Double-sided tape is for anchoring a rug to a floor. You want your patch to float above the carpet pad like the surrounding carpet.
The easiest type of carpet-seam tape is pressure-activated, such as Roberts Indoor Pressure Sensitive Carpet Seaming Tape Roll ($4.97 at Home Depot). But a better bond comes from using tape with heat-activated adhesive, such as Roberts Heat-Loc Heat Bond Carpet Seaming Tape Roll ($6.99 at Home Depot).
The heat-set tape is designed to be used with a dedicated carpet iron, such as the TruePower 10-Inch Carpet Seaming Iron ($48.11 on Amazon). This tool slips under a seam and applies heat directly to the tape. A good YouTube video showing how to patch like a professional is at bit.ly/2uBBSdn. There are also videos showing how to patch with an iron and a damp towel. But first test the process on extra scraps to determine how long you need to leave the iron in place to get a good bond and to make sure you won’t be melting the carpet fibers.
The main steps of patching are the same with either type of seam tape.
First, cut out the damaged area of your carpet, using a utility knife or a carpet knife with a sharp blade. Rather than trying to follow the irregular edges around the hole, go for a rectangle or other tidy shape that includes the damaged area. Because the damage is near a doorway, include the full width of that space and even a bit more, assuming you have a remnant big enough. For a tidy cut, run a pen (with the tip retracted) along each line you need to cut to separate rows of carpet fibers, and then run the knife along a metal straightedge, such as a ruler or framing square.
Use the piece of carpet you removed as a template for cutting the patch. Carpet is easier to cut from the back, so flip over your template piece and place it on the back of the patch material. But take care first to match the nap direction of the carpet and patch. (Run your hand over the carpet and determine which direction feels smoother, as if you were petting a cat.)
Next, cut pieces of seam tape to ring and underlie the opening in the floor, with about half the tape’s width visible and half tucked under the carpet. Then fit the patch into the opening. “Match it up like a puzzle,” says Jamal Jones, owner of Everette Carpet Care & Restoration in Fairfax (877-783-3606; everettecarpet.com), who has been doing carpet repairs for about 20 years.
If you are using pressure-sensitive tape, check to make sure the edges fit well and that no fibers are trapped in the seams. Then simply push down the patch to secure it. With a brush, work the fibers back and forth to blend in edges of the patch.
For heat-set tape, dampen a terry-cloth towel and place it over the patch, or a section of a large patch. With the iron set on high (or cotton), press through the cloth to set the adhesive. Several YouTube videos recommend leaving the iron in place for about 60 seconds. But Jones goes for only five to 10 seconds and repeats that several times, as one would when ironing clothes that need more than a simple swipe of an iron. Any longer, he says, and you risk melting the carpet fibers. Brandi Long, technical service and claims manager for QEP, which owns the Roberts seam-tape brand, cringed at the idea of using an iron on the fibers, rather than heating the adhesive with an iron and then slipping it underneath the carpet seam. “You do run the risk of ruining your carpet,” she says.
So, who is right? Do a test yourself with scraps of your own carpet. On a remnant, patch in a small square, say 2-by-4 inches. Do this where you don’t have to worry about damaging the underlying surface — perhaps on scrap board or on a paved outdoor surface.
Or just call a pro and leave the worries to someone else. Jones said he charges $150 for a patch when a customer has matching carpet pieces. When there is no carpet to use for a patch, many carpet companies harvest a piece from an out-of-the-way place, usually a closet. Jones sometimes resorts to that, but he said he’s often able to get enough patch material by restretching the carpet and then cutting off a piece of the new excess. For that, the cost goes up by about $75.
More from Lifestyle: