A joint is the seam between two bricks, natural stones, or tiles that is filled with mortar or jointing material. Joints provide the bond between the stones, distribute forces, and make the wall watertight. The finish of the joint also contributes to the appearance of the brickwork.
Types of joints
Bed joint (horizontal)
The horizontal seam between two courses of bricks. Standard thickness: 10-12 mm.
Perpend joint (vertical)
The vertical seam between two bricks in the same course. Standard thickness: 10 mm.
Joint finishes
The way the joint is finished determines the appearance and water resistance:
| Type | Description | Water resistance |
|---|---|---|
| Flush joint | Finished flush with the brickwork | Good |
| Recessed joint | Slightly recessed (2-3 mm) | Moderate (water can pool) |
| Concave joint (bucket handle) | Rounded out with a jointing tool | Good (water runs off) |
| Weathered joint | Recessed at the top, flush at the bottom | Good, decorative |
| Struck joint | Mortar protrudes slightly | Less good (breaks off easily) |
Joints and mortar
The joint is filled with mortar — a mix of cement, sand, and water. The mortar strength must match the brick type:
- Soft bricks (handmade) → soft mortar
- Hard bricks (machine-made) → hard mortar
Mortar that is too hard for soft bricks causes cracks in the bricks instead of in the joint.
Repointing (replacing joints)
On older walls, joints wear out over time. Repointing involves:
1. Remove old mortar — With a joint raker or angle grinder, at least 15-20 mm deep
2. Blow out/rinse — Remove dust and loose debris
3. Dampen — Dry brickwork absorbs moisture from the new mortar
4. Apply jointing mortar — With a pointing trowel or mortar gun
5. Finish — Shape the desired joint profile
Related terms
- Bond pattern
- Mortar
- Half-brick wall
- Single-brick wall