Hob
A hob is the raised threshold at the entry of a shower or wet area that contains water within the zone. NCC 2022 specifies permitted materials.
Ask Chalkline about this →A hob is the raised threshold at the entry of a shower recess or wet area, built to contain water within the zone and prevent it spreading to the surrounding floor. It is the substrate over which the waterproofing membrane is applied and terminates.
Under NCC 2022 Housing Provisions Part 10.2.16, hobs must be constructed from masonry, concrete, autoclaved aerated concrete, or extruded polyurethane foam. Timber is not permitted. All gaps, joints, and intersections of the hob substrate must be made flush before the membrane is applied, and the hob must be adequately secured to the floor and sealed against the wall.
Regulatory direction (2026): the broader trend in residential wet-area design is toward hobless (level-entry) showers. NCC 2022 Volume Two already mandates a step-free shower entry to at least one bathroom in new Class 1 dwellings under the Livable Housing minimum accessibility provisions. The next NCC review cycle and HIA briefings flag further tightening on hob-and-step thresholds for accessibility, particularly in adaptable housing scope. Confirm the current NCC adoption status in your jurisdiction at design stage.
Also known as: shower hob, shower dam, threshold.
Category: Wet areas.
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Last updated: 2026-05-08. Verified: 2026-05-08. Quarterly review for currency.