A corner bead is a metal, vinyl or paper-faced trim installed on outside corners of drywall to protect the edge from damage and create a straight, clean line. It is fastened or adhered to the corner, then covered with joint compound and sanded as part of the drywall finishing process.
Types of corner bead
| Type | How it’s attached | Best for |
|---|---|---|
| Metal (galvanized steel) | Nails, screws or a crimping tool | Low cost, general use; can rust if damaged in wet areas |
| Paper-faced metal or composite | Set in a bed of compound or spray adhesive | Resists edge cracking; common on commercial work |
| Vinyl (PVC) | Spray adhesive and staples, or compound | Dent-resistant, won’t rust; humid areas |
| Bullnose | Metal, vinyl or paper-faced | Rounded corners in several radii |
| Flexible or arch bead | Vinyl or paper-faced, bends to shape | Arches and curved walls |
| Off-angle (splay) bead | Paper-faced or adjustable | Corners other than 90 degrees |
The same family includes L-bead and J-bead, which finish exposed drywall edges at windows, ceilings and other materials, and expanded-metal corner beads for plaster and stucco. In North America, drywall accessories are generally covered by ASTM C1047.
How to install drywall corner bead
- Check the corner. Board edges should be tight and fastened, and the corner straight.
- Cut the bead to length, in one piece floor to ceiling where you can, leaving a small gap at the floor.
- Fasten metal bead along both flanges per the manufacturer, or press paper-faced bead into a thin bed of compound and wipe out the excess.
- Apply the first coat, feathered several inches past the flange.
- Apply wider second and third coats, letting each dry.
- Sand lightly without cutting into the bead’s nose, then prime.
The finish level the spec calls for (Level 4, Level 5 and so on) affects how many coats you need; see our drywall finishing guide.
Common problems
- Cracks along the flange edge: loose bead or too little compound under paper-faced bead.
- Wavy or rolling corners: out-of-plumb framing or bead installed off line.
- Rust spots: metal bead in a damp area or nicked during sanding.
- Dents: high-traffic corners; consider heavier or vinyl bead.
What beading means in construction
“Beading” is used loosely on site. It can mean:
- Plaster and drywall beads: corner beads (called angle beads by UK and Australian plasterers), stop beads at edges and render beads on exterior walls.
- Glazing beads: the strips that hold glass in a window or door frame.
- Timber beading: small trim mouldings used to cover joints or finish edges.
Related terms
Related templates and guides
- Levels of Drywall Finish Whitepaper
- Wallboard Finished Appearance Best Practices
- QA/QC Checklist: Drywall Partitions
- Drywall Project Cost Estimate Template
Frequently asked questions
What is corner bead used for?
Corner bead protects outside drywall corners from dents and chips and gives the finisher a straight, crisp edge to run compound against. Without it, the exposed gypsum and paper at a corner crumble easily and are almost impossible to finish straight.
Is metal or vinyl corner bead better?
Neither is better everywhere. Metal is cheap and rigid but can rust or dent. Vinyl doesn’t rust and resists dents, which suits humid or high-traffic areas. Paper-faced bead is often preferred for crack resistance because the compound bonds well to the paper.
What does beading mean in construction?
It usually means the trims plasterers and drywallers use on corners and edges, such as corner (angle) beads and stop beads. It can also mean the glazing beads that hold glass in a frame or small timber trim mouldings, so check the context.
Can you install corner bead with screws?
Yes, metal corner bead can be screwed or nailed through the flanges into the framing, as long as fastener heads sit below the bead’s surface so they can be covered. Paper-faced and vinyl beads are normally bedded in compound or adhesive instead.
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