In drywall construction, a corner bead is used wherever the walls or ceiling meet to form a corner. It gives a crisp edge, hiding any gaps or imperfections for a professional look. They are most commonly found in metal and vinyl, and there are several types for varying designs and uses.
Specifically designed for trims, J-bead covers drywall edging that otherwise would be left unfinished. Similarly, L-bead covers edging that butts up against a material other than drywall. Archways require a special flexible corner bead, while rounded corners need a bullnose corner bead. For large surface areas of drywall, expansion joints are used between drywall seams.
Corner Bead Material
The most common corner bead materials consist of metal and vinyl. You may also find plastic covered in paper or metal covered in paper.
Metal Corner Bead
Galvanized metal corner bead is the DIY-er’s best friend. Not only is it the least expensive option, but it’s also super easy to install. Mount with nails, screws, compound, adhesive, or staples—the choice is yours!
Metal corner bead resists rust. Once installed, it’s just shy of indestructible. However, it tends to twist and bend during transportation, especially when left in longer strips. Take extra care in those instances.
Vinyl Corner Bead
The plastic version of the metal corner bead, vinyl corner bead is just as easy to install. While it may require a special compound or adhesive at times, all the metal installation methods can be used with vinyl corner beads, too.
The slight rigidity of the plastic makes vinyl corners beadless prone to bend or twist during transportation.
If you have an older house, you’ve probably noticed the settlement cracks. Drywall expands and contracts as time goes on which causes cracks and potentially exposes corner beads. The paper-faced bead is more likely to prevent cracking because it’s better able to adhere to the drywall compound.
Available in paper-covered metal or paper-covered plastic, paper-faced bead gives a highly professional, sharp, and crisp edge.
If you’re lucky enough to have a beautiful archway in your home, know that it required extra care in its creation. Think about an archway for a minute. It doesn’t have corners and yet the drywall on either side has to meet. Installing metal or vinyl corner beads seems like such a headache!
Thank goodness there’s a special corner bead designed specifically for archways. They can come in metal, plastic, or composite materials, but the difference is archway corner bead is flexible!
The wire bead has a plastic edge and is installed with nails. It’s available in lengths of up to 10 feet.
The edging of vinyl bead is pre-snipped to allow for flexibility. To install, glue the edge in place and staple over top. In addition to a 90-degree angle, the archway vinyl bead also comes with a bullnose edge.
The composite bead is a type of paper-faced bead, with paper covering a PVC core. It’s installed with a joint compound. This type of beading is available in rolls of up to 100 feet in length. Some even have adhesive backing with reinforced wire edges for easy installation.
Trim Corner Bead
Just as archways require special corner beads, so too do areas with trims. The trim bead comes in two types: J-bead and L-bead. But both are available in metal, plastic, or paper-covered materials. J-bead and L-bead get their names because their respective flanges form the shape of the letter.
The trim bead comes up to 12 feet in length. It’s made for drywall that’s either 1/2-in or 5/8-in thick.
Sometimes, our wall doesn’t end in a corner. For example, a pull-down attic access in the ceiling requires cutting a hole in the drywall. In this instance, you would use J-bead.
J-bead caps the edge of drywall that would otherwise be left unfinished—a window or door jamb, against a shower stall, or that attic opening we mentioned before.
Available in a variety of thicknesses depending on your drywall, J-bead can be installed before the drywall is hung or once it’s loosely attached. Some types need finishing with compound, but others only need nailing or screwing to the wall.
Sometimes, our walls meet up with a different material, like a window. In this instance, you would use L-bead.
L-bead has one flange that’s longer than the other. The shorter edge gets inserted between the drywall and the neighboring material, and the exposed edge gets finished with the compound. In addition to windows, L-bead can be used against a paneled wall, fireplace, or countertop.
Certain brands of L-bead have a strip that protects the non-drywall material from paint or compound. It’s removed after the afore-mentioned applications.
Because it’s attached after the drywall is in place, L-bead is typically easier to install than J-bead.
Bullnose Corner Bead
When your project requires rounded corners, you would use a bullnose corner bead. These offer an elegant look as compared to the sharp angles of regular corner beads. And they’re just as easy to install.
Bullnose corner bead comes in a variety of arc sizes and is available in metal or vinyl. The same manner of installation is used for bullnose corner beads as with 90-degree metal or vinyl corner beads.
Stylistically, bullnose corner bead gives a sense of openness to a room. It smoothes the sharp angles of the walls, reducing the severity and bringing a contemporary feel.
Used especially on large wall surface areas, expansion joints prevent the drywall from cracking or buckling due to normal expansion and contraction. These are placed between drywall panels and are not covered with joint compounds. Rather, they can be filled with flexible caulk.
When installing drywall, leave a 1/4-in gap every 30 feet between panels. Place the expansion joints in these gaps.
Expansion joints can be either U-shaped or V-shaped and come in either metal or vinyl. They run from wall to wall on a ceiling and ceiling to floor on the walls.
Inside Corner Bead vs. Outside Corner Bead
Walls can have either an inside corner or an outside corner and thus require a specific corner bead.
Outside corner bead is used to protect and reinforce the corner of the wall (think, cased opening). It’s raised slightly to ensure a straight edge. Metal is the sought-after material for outside corner beads. However, vinyl can also be used.
Inside corner bead is used in the corner of a room (think, where you got sent as a kid). It replaces folded tape which is the method used to hide the gap where two drywall panels meet. Corner bead is much more structurally sound than tape, making it easier to work with and providing crisp, clean inside corners.
Both inside and outside corner bead can be a bullnose finish or 90-degree angle, depending on your aesthetic.