Lintel end bearing length

100 mm for spans up to 1200 mm; 150 mm for longer spans

Masonry openings — confirm against the lintel manufacturer's schedule for the specific span and load

The minimum length of masonry each end of a lintel must bear onto.

Basis in regulation

Part A
Approved Document A
Read the source

How to check it on site

Measure the bearing at both ends before the opening is closed up, and check the bearing masonry is solid, level and fully bedded.

Common failure

Lintels cut short or slid across after delivery, leaving one end with reduced bearing onto a perp joint.

Effective from 20 August 2026. Last updated 23 August 2026. This is our editorial summary of publicly available regulation, not building control approval or a warranty determination.

Related dimensions at this stage

Maximum

Wall tie spacing at reveals and movement joints

Additional ties at 300 mm vertical centres within 225 mm of the opening

Within 225 mm of an unbonded vertical edge — reveals, movement joints, wall ends

Maximum

Cavity wall tie vertical spacing

450 mm

vertical spacing of cavity wall ties does not exceed 450mm.

Maximum

Cavity wall tie horizontal spacing (partial-fill insulation)

600 mm

horizontal tie spacing for partial-fill insulated cavities does not exceed 600mm.

Maximum

Cavity wall tie horizontal spacing (full-fill insulation)

900 mm

For cavity walls incorporating full-fill insulation, wall ties must be placed at maximum 900mm horizontal centres

Maximum

Lowest fixing position for straps

150 mm

For any structural strap, the lowest fixing into the masonry or supporting structure must be positioned no more than 150mm from the bottom of the strap

Minimum

Chimney wall thickness and construction

100 mm

The minimum wall thickness for block, brick, or stone chimneys, excluding flue lining, is typically 100mm