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Movement Joint Spacing — Masonry Reference
Maximum spacing for movement joints in clay brick, concrete block, and calcium silicate masonry. Width calculations, sealant requirements and joint profiles.
Movement Joint Spacing by Material
Reference: BS EN 1996-2, PD 6697, BS 5628-3 (withdrawn but still referenced).
| Masonry Material | Max Spacing (m) | Max from Corner (m) | Movement Type |
|---|---|---|---|
| Clay bricks (external) | 12 | 6 (max 7.5) | Expansion |
| Clay bricks (internal) | 15 | 7.5 | Expansion |
| Concrete blocks (external) | 6 | 3 | Contraction |
| Concrete blocks (internal) | 9 | 4.5 | Contraction |
| Calcium silicate bricks | 7.5 – 9 | 3.75 – 4.5 | Contraction |
| Natural stone (ashlar) | 12 – 15 | 6 | Expansion |
Additional Locations for Movement Joints
- At changes in wall height or thickness
- At setbacks or returns in plan
- Adjacent to columns or structural frames
- At each side of window and door openings in long walls (if near the maximum spacing)
- Where different masonry materials meet (e.g., clay over concrete block)
- At junctions between new and existing construction
- At every floor level change in multi-storey construction
Joint Construction Details
| Component | Specification |
|---|---|
| Joint width | 10-13mm for brickwork, 10mm for blockwork |
| Backer rod | Closed-cell polyethylene foam, 25% larger than joint width |
| Sealant depth | Half the joint width (min 6mm, max 12mm) |
| Sealant type | Low modulus silicone or polysulphide to BS EN ISO 11600 |
| Compressible filler | Flexible foam strip (for expansion joints in cavity) |
| Wall ties at joints | Debonding sleeves or sliding ties to allow movement |
Note: Spacings shown are general guidance. Actual spacing depends on exposure, restraint conditions, and the specific coefficient of thermal and moisture expansion for the product used. Refer to BS EN 1996-2 and PD 6697 for definitive guidance.
Related Pages
See the Brick Bond Patterns, the Mortar Suction Rates, and the Weep Hole Spacing guide.
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Last updated: April 2026
Verified against UK standards · estimates only, confirm with your supplier.