The Decision You're Making
Handrail tactile indicators are widely misunderstood. They are often described as the thing you use "when floor tactiles aren't required", which is not what the National Construction Code says. The allowance is narrower than that, and specifying a handrail button outside it will not satisfy a certifier.
This page sets out what NCC D4D9(3) actually permits.
When can a handrail button replace floor tactiles?
NCC D4D9(3) permits a handrail incorporating a raised dome button, in accordance with AS/NZS 1428.4.1, to be provided as an alternative to tactile ground surface indicators, warning a person who is blind or has a vision impairment that they are approaching a stairway or ramp.
This allowance applies to aged care buildings: Class 9c residential care buildings, and Class 3 and Class 9a residential aged care. It is not a general substitution available across all building classes.
The reason is practical. Ground surface indicators can hinder people using walking frames and similar mobility aids, so in an aged care setting the raised dome on the handrail delivers the warning without putting a raised profile in the path of travel.
Two things specifiers get wrong.
First, this is a permission, not a requirement. D4D9(3) allows the handrail button as an alternative in those buildings. It does not oblige you to use one.
Second, it is not a general rule that a handrail button covers you anywhere TGSIs are absent. Outside the aged care classes, where D4D9 calls for warning TGSIs, warning TGSIs are what is required.
Where are floor tactiles required in the first place?
Under D4D9, warning TGSIs are for specific hazard identification, principally at the top and bottom of stairways, escalators and ramps, and where there is an overhead obstruction less than 2m above the floor without a barrier preventing someone walking into it.
There are also exemptions, including stairways and ramps leading only to areas exempted under D4D5, and enclosed landings between flights where no other entrance or exit leads onto the landing. An exemption means no tactile is required at that location. It does not mean a handrail button is required instead.
What size does the button have to be?
A domed button, 10mm to 12mm in diameter and 4mm to 5mm high, in accordance with AS/NZS 1428.4.1, which is the standard D4D9(3) points to.
Where does it go on the handrail?
On the top face of the handrail, 150mm from the end. Top face matters: a button fixed to the side is not in the path of a hand travelling along the rail and will not be felt. The setback exists so the warning arrives before the hand reaches the terminal, not at the same moment.
Is a handrail button a TGSI?
No, and the distinction changes what evidence a certifier will ask for.
A tactile ground surface indicator is a floor-mounted element with luminance contrast requirements against the adjacent floor surface and a slip resistance classification, because people walk on it. A handrail button is fixed to a handrail. There is no adjacent floor surface to contrast against and nobody walks on it, so neither a luminance contrast figure nor a slip class is meaningful for it.
If a supplier hands you a luminance contrast number or a P5 slip rating for a handrail button, the product has been filed under the wrong category rather than assessed on its own terms.
Materials and fixing
The button is fixed, not adhered. A shaft on the underside of the dome sets into a drilled hole in the handrail so the dome seats flush on the top face. That matters at specification stage: the handrail has to be drillable, and the fixing has to be coordinated with whoever supplies the balustrade.
Stainless steel is the usual choice for the same reason it is used for the handrail itself. It is handled constantly, it lives outdoors as often as not, and a coated finish will not survive that traffic.
Common Non-Compliance on Site
- Used outside the aged care classes, on the assumption that a handrail button is a general substitute for floor tactiles. It is not.
- Fixed to the side of the rail rather than the top face, where a travelling hand will not find it.
- Wrong setback, placed at the very end of the rail instead of 150mm back.
- Adhered rather than fixed, which does not survive handling.
- Specified as a TGSI, which produces the wrong compliance evidence at handover.
This page summarises how D4D9 is applied and is not a substitute for the NCC itself or for advice from a building surveyor or access consultant on a specific project.
Korb supplies this as the Nouvel® Dome. Stainless steel, Infix fixing, domed button 4mm to 5mm high and 10mm to 12mm in diameter, fixed to the top of the handrail 150mm from the end. Five year product warranty.
Its data sheet states plainly that it is not a TGSI, because a document that overstates what a product is creates work for the person relying on it.
View the Nouvel Dome handrail button or talk to us about a project.