What Is the Differece Between Self-Adhesive & Joint Tape for Drywall?

Paper Tape Came First

• Paper was the standard drywall tape for many years, although it was fastened with joint compound, not adhesive. Workers spread a layer of joint compound across the seam where two drywall panels meet. They lay the paper tape over the joint compound and secure it with another layer of joint compound. The first innovation in paper tape was putting a crease down the center so it could be folded easily to fit corners as well as cover flat seams. Paper tape typically requires three coats of compound.

Fiberglass Mesh Tape Is Pre-Pasted

• Fiberglass mesh tape is a fairly recent introduction. It works much like paper tape, and it is made of thin fiberglass in a tight mesh pattern. It typically has a self-adhesive, or pre-pasted, backing, which holds it to drywall without a first layer of joint compound. That feature makes its installation faster and finishing easier because it requires only two coats of joint compound. It is sealed with a layer of joint compound and finished with another layer, just like paper tape.

Professionals Use Both Tapes

• Most professional drywall installers use both paper and pre-pasted or self-adhesive fiberglass mesh tape. Paper tape adapts to corners, especially those at angles other than 90 degrees, more easily than fiberglass mesh tape. The adhesive on fiberglass mesh tape tends to dry out over time, and so it may not adhere firmly if it has been sitting for a while. That factor is not a problem with paper tape.

Pre-Pasted Paper Tape Is an Option

• Some paper tape is available pre-pasted, with a self-adhesive backing, but professionals tend to avoid that form. The moisture in drywall compound can affect the adhesive on the pre-pasted paper tape. So it does not adhere securely to the drywall and causes bubbles in the joint. The only cure for bubbling under joint tape is to remove the old tape and replace it with new tape.

Each Kind Has Special Uses

• Fiberglass mesh tape is very good for patching drywall because it provides stronger support for joint compound. It can be used to patch holes up to 3 inches in diameter. It also will not tear, is fire-resistant and is not subject to mold infestation. Paper tape, however, is stronger and more adaptable to tight corners and odd angles because it is less rigid and easier to make conform to those joints.