Broom finish (concrete)

A broom finish is the linear-textured concrete surface produced by dragging a stiff-bristled concrete broom across the surface of freshly screeded and floated concrete, after the bleed water has dissipated but before the concrete has set hard. The broom creates parallel grooves typically 1-3 mm deep that substantially improve slip resistance when the surface is wet. It is the default external concrete finish in Australian residential construction for driveways, paths, pool surrounds, and ramps, and meets AS 4586:2013 P-class slip resistance for typical external applications. Verified per AS 4586:2013 and standard concretor practice (2026-05-16).

When to use a broom finish:

Application	Reason
Driveways	Tyre traction; AS 4586 slip resistance for foot traffic
External paths and footpaths	Pedestrian slip resistance in wet weather
Pool surrounds and patios	Wet-foot slip resistance (P3 or P4 typically)
External ramps	DDA / Premises Standards slip resistance
Carport floors	Slip resistance + adequate drainage when wet
Building approach paths	Compliance with the Building Code accessibility provisions

(Internal surfaces typically use a steel-trowel finish for smoothness; broom finish is rarely seen internally except in service areas and garages.)

Application sequence:

Place the concrete to the desired slope (typically 1:80 fall on driveways, 1:50 on pool surrounds for drainage).
Screed with a straight edge to the planned finish level.
Float with a wood or magnesium float to consolidate the surface and bring up some cream.
Wait for the bleed water to dissipate (15-45 minutes depending on weather; the surface should be sheen-free but still workable).
Edge with an edging tool around the perimeter and any expansion joints.
Joint to create control joints at maximum 1.5x the slab thickness spacing typically (e.g. 100 mm slab → 1.5 m joint spacing).
Broom with a stiff concrete broom (not a household broom), pulling in straight lines perpendicular to the direction of foot traffic.
Cure with a curing compound or water spray for at least 7 days.

Broom direction matters:

Direction	Effect
Perpendicular to traffic	Maximum grip; the standard direction
Parallel to traffic	Less grip; reserved for decorative effect; not for slip-critical surfaces
Curved or pattern	Decorative; rare for residential

AS 4586 slip resistance classes for broom finish (typical):

Test condition	Typical broom finish rating
Wet pendulum (BPN)	35-50 BPN, suitable for P3 (most external residential)
Dry oil pendulum	50+ BPN, P5 (high traffic external)
Wet ramp	R10 typical, suitable for most residential external

Higher slip resistance can be achieved with deeper brooming, sandblasting, or surface aggregate exposure.

Common defects:

Brooming too early (concrete still bleeding): the broom tears the surface and creates an open, weak texture that erodes.
Brooming too late (concrete starting to set): the broom skids and creates inconsistent groove depth.
Inconsistent groove depth across the slab: visual defect and inconsistent slip resistance.
Different broom directions across one slab (left-to-right on half, right-to-left on the other): visible at low sun angles, aesthetic defect.
No curing compound applied: dust and surface scaling within months as the surface dehydrates.
Broom finish applied to inadequate concrete cover: the broom exposes aggregate or reduces the slab’s wear depth.

Alternative external finishes:

Finish	When used
Broom finish (this)	Most external applications
Stamped concrete	Decorative driveways and patios; mimics paving
Exposed aggregate	Decorative external; better slip resistance than broom but more expensive
Sandblasted	Heritage-style, premium
Stencil-stamped concrete	Mimics paver patterns
Honed concrete	Premium internal-feel external; less slip-resistant

Also known as: brushed finish; concrete broom finish; broom texture; pulled-broom finish.

Category: Materials.

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