Why do store doorways need threshold ramps at all?
Most retail doorways were never built dead level. A sliding entry sits on a track, a click and collect door sits behind a roller shutter with a lip, and a back of house door steps down to a loading apron. Each one leaves a small rise that a customer with a trolley, a parent with a pram or a person in a wheelchair has to get over.
On a single store that is a maintenance job. Across a fleet it becomes a standards problem, because every doorway is a slightly different height and every local contractor fixes it a slightly different way.
What are the limits in AS 1428.1?
AS 1428.1 sets out several kinds of ramp, and the kind you are allowed to use depends on how big the rise is. These are the figures the standard gives, as published in its access guidance and repeated by suppliers who test to it:
| Type | Maximum gradient | Maximum rise | Maximum length |
|---|---|---|---|
| Threshold ramp | 1:8 | 35 mm | 280 mm |
| Step ramp | 1:10 | 190 mm | 1900 mm |
| Kerb ramp | 1:8 | see the standard | see the standard |
| Ramp longer than 1900 mm | 1:14 | see the standard | landings at set intervals |
Every one of these also needs a firm, slip resistant surface that does not flex under a wheel. A soft mat that curls at the edge fails that test even if its gradient is right.
The edition of the standard that applies to a particular building, and whether a particular doorway has to meet it, is set by the National Construction Code and the Premises Standards at the time of the work. That decision belongs to your building certifier or access consultant, not to the person installing the ramp.
What if the rise is more than 35 mm?
Then a threshold ramp is the wrong product, however well it is made. A rise above 35 mm pushes the job into step ramp territory, which allows a longer run at a shallower 1:10, or into a kerb ramp or full ramp. Each of those needs more floor space in front of the door, and that space is often the thing a store does not have.
This is where most fleet problems start. The rise is measured at one store, a ramp is chosen to suit it, and the same ramp is ordered for every other store without anyone measuring their doors.
How much room does a full ramp actually need?
The section above says a full ramp needs more floor space than a doorway usually has. This is how much, and it is the part worth checking before anyone orders anything:
| What | The limit |
|---|---|
| Kerb ramp | 1:8, up to a 190 mm rise over 1520 mm |
| Anything longer than 1900 mm | 1:14, so 14 mm of run for every 1 mm of rise |
| Landings | At the top and bottom, then every 9 m on a 1:14 ramp |
| Landing size | 1200 mm long, or 1500 mm by 1500 mm where the ramp turns |
| Clear width | 1000 mm minimum between the handrails |
| Handrails | Both sides, 865 mm to 1000 mm above the ramp surface |
Work it through on a real doorway and the problem becomes obvious. A 150 mm step is past the 35 mm threshold limit, so at 1:14 it needs 2.1 metres of run, plus a landing at each end. That is most of a footpath, which is why the answer at many doors is a step ramp at 1:10 rather than a full ramp, and why a few doors cannot be solved with a ramp at all.
Whether a given door complies is still the building certifier's or access consultant's call, not a contractor's. The figures are here so the question gets asked at the right time, which is before the fleet order goes in.
Rubber, aluminium or concrete?
- Recycled rubber ramps are quiet, grip well and can be cut to a measured opening. They suit most threshold and small step situations.
- Aluminium ramps are light and strong, and suit longer runs or places where a ramp has to be lifted away, but they need a slip resistant finish.
- Concrete or built up work is permanent and suits larger rises, but it is a building change, with drainage and approvals to think about.
None of these is right everywhere. The useful decision is which one is right for each type of door in your fleet, written down once so it stops changing.
How do you fix thresholds across a whole store fleet?
- Measure every door that is in scope. A drawing does not show a worn track or a slab that has moved.
- Group the doors by type and by rise, so the fleet becomes a handful of cases instead of hundreds of one offs.
- Freeze one kit per case: material, dimensions, finish and fixing method.
- Price each store, so the work can be staged against the capital cycle.
- Photograph each door before and after, so the budget owner can close the site out without visiting it.
That is the way Nextage runs click and collect and drive up ramp programs: each door measured, the ramp fabricated to that opening, commonly in Tyrex rubber or an equivalent specified pack, installed by induction ready crews and reported per site. We do not certify compliance. Where a doorway needs a compliance view, that comes from your certifier, and we build to what they set.
