Access & mobility · 9 min read
Access & mobility
Threshold Ramps for Doorways: When They Help, When They Don't
10 March 2026 · 6 min read
AI overview
A threshold ramp bridges a small door sill or step - typically 20 mm to 75 mm high - to allow a wheelchair or walking frame to cross without lifting. The right ramp type depends on the height of the threshold and how much floor run is available: rubber ramps suit steps under 30 mm, aluminium suit 30 - 75 mm, and a built-in tapered screed is the best permanent answer for any height that allows a 1:8 gradient within the available space. Above 75 mm, a threshold ramp becomes a trip hazard in its own right and a structural ramp is needed instead.
Key highlights
- Rubber threshold ramps suit door sills from about 20 mm up to 120 mm - quick and weatherproof
- Aluminium modular threshold ramps handle 30 - 75 mm and are more stable
- A tapered concrete or screed ramp is the most durable permanent answer
- Maximum gradient for an accessible threshold ramp is 1:8 (very short ramps only)
- Wheelchair clear width at a doorway should be at least 810 mm - the ramp must not reduce this
- Weather sealing matters: an aluminium ramp with a raised lip creates a new trap for water
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What is a threshold ramp and when is one the right call?
A threshold ramp is a wedge - rubber, aluminium or cast concrete - that bridges a small step at a doorway so that a wheelchair, walking frame or wheeled trolley can cross it without the front wheels dropping off the edge or the user having to lift and step over.
They work well for door sills in the 20 mm to 75 mm range where the floor run on each side is enough to achieve a safe gradient. The maximum gradient for a threshold ramp under AS 1428.1 is 1:8 - steep but acceptable for a very short ramp where a carer is present or the user has good upper-arm strength. A gentler gradient of 1:14 is recommended wherever the run allows.
Below 20 mm, a threshold ramp often creates more hazard than it solves. A thin rubber wedge on a smooth floor becomes a tripping hazard for anyone walking over it - particularly on the way back when attention is elsewhere. Above 75 mm, the ramp becomes too steep for independent wheelchair use unless there is a lot of floor run available.
Rubber ramps - the quick option
Rubber threshold ramps are the easiest to install and the least expensive. They come in a wide range of sizes, and rubber works up to about 120 mm high before the weight and the cost start to count against it. Inside the door, for a sill of 20 mm to 50 mm, expect $200 - $350 supplied and installed. Outside the door, for 60 mm to 120 mm, expect $400 - $790. They are heavy enough for their size that they usually stay put, though some floors need a little glue or silicone.
The disadvantage is stability. An unfixed ramp shifts underfoot, particularly when the wheelchair or frame pushes it on the approach. Most people use a double-sided adhesive mat or a thin bead of silicone to hold the ramp in position - but in a doorway with a weather seal, the ramp then becomes a permanent fixture that compresses the seal.
For outdoor use, rubber degrades in UV over three to five years. Perth's sun accelerates this. A rubber ramp that has started to crack or compress at its thinnest edge is less safe than no ramp at all, because the edge becomes unpredictable underfoot.
Aluminium ramps - the more stable temporary solution
Aluminium threshold ramps are more substantial and handle heights of 30 mm to 75 mm more reliably. They come as single-piece extrusions or as two-piece flip ramps with a hinge at the apex. Priced by doorway, a threshold ramp runs $200 - $350 inside the door for a 20 mm to 50 mm sill, $400 - $790 outside the door for 60 mm to 120 mm, and $1,500 - $2,000 for aluminium checker plate out in the weather at 130 mm to 180 mm.
Fixed aluminium ramps are secured with screws into the floor on each side of the threshold. This prevents movement but makes them permanent - removing them later leaves fixings in the floor. For a door that is used as the main entry for a wheelchair user, that is an acceptable trade-off.
The risk with aluminium ramps is a raised lip at the edges. Some cheaper models have a lip of 5 - 10 mm at the top of each side where the ramp meets the door threshold - that lip is itself a trip hazard for anyone who walks over it rather than rolling over it. Look for a ramp with a tapered, bevelled edge on all four sides, not a box section.
A built-in tapered screed - the best permanent answer
Where the threshold height is within a range that allows a 1:8 or gentler gradient using the available floor space on each side, a tapered concrete or tile-over screed is the most durable and most usable answer. It costs more than a modular ramp - typically $800 - $2,500 supplied and installed - but it is fixed, invisible, and does not create a separate object to trip over.
A tapered screed is built up from the lower floor level to match the higher threshold, then feathered back at a gradient of 1:8 or less. On the high side, the floor comes to meet the threshold rather than leaving a step. Tiled over in a matching or complementary tile, the transition looks intentional rather than retrofitted.
This approach is particularly effective at back door thresholds where the indoor floor and the outdoor paving are at slightly different levels - a common situation in Perth homes where patios have been laid over time without matching the internal floor height.
Wheelchair and walker clearance through the doorway
A threshold ramp solves the vertical transition but does nothing about the clear width of the door opening. A standard 820 mm internal door in a Perth home provides about 780 mm of clear width when open - narrower than the 820 mm minimum for a manual wheelchair and well below the 900 mm preferred for comfort.
The threshold ramp must not narrow the opening further. Some ramp designs have side flanges that extend across the door sill - if these flanges reduce the clear width below 810 mm, the ramp creates a new access problem while solving an old one. Measure the clear width with the ramp in position before accepting the installation.
For walking frames (wheelie walkers), the clear width requirement is 760 mm. Most standard doorways can accommodate a walking frame with a ramp in place, but it is worth checking. A frame with a wide wheel base may catch the flanges of a ramp that has not been positioned accurately.
Weather sealing and outdoor thresholds
External door thresholds need to keep rain out. The threshold sill typically creates the weathered joint between the interior floor and the exterior, with a rubber or brush seal under the door. A threshold ramp placed over this seal compresses it and can prevent the door from closing fully - which defeats the weather protection.
For external thresholds, a door sill ramp with a channel milled into its base to sit over the existing sill, without compressing the seal, is the right specification. These are more expensive than a flat ramp and not all suppliers stock them - ask specifically for a ramp with a weather-seal channel.
The alternative is a structural ramp to the door that brings the external paving level up to the threshold height, eliminating the need for a portable ramp entirely. This also solves the drainage question: a properly graded external ramp directs water away from the door rather than pooling at the threshold.
Related services
- Ramps & level entry - Rubber, timber, aluminium and concrete ramps built to the right gradient, from a door threshold to a full exterior ramp.
- Doorway widening - Wider clear openings for wheelchair and walker access.
Questions about this topic
What is the maximum height for a threshold ramp at a doorway?
In practice, threshold ramps work best for steps up to 75 mm. Above that height, the ramp gradient at 1:8 requires more floor run than most doorways have, and an aluminium or rubber ramp at steep angles becomes difficult to wheel over independently. A structural ramp is the better answer for anything over 75 mm.
Will a threshold ramp damage my door seal?
A flat ramp placed over an existing weather seal can compress and damage it over time. Look for a ramp with a channel milled into its base that sits around the seal rather than on top of it. For external doors, having the ramp fabricated to fit the specific sill profile avoids this problem.
How much does a threshold ramp cost in Perth?
A rubber threshold ramp inside the door, for a sill of 20 mm to 50 mm, costs $200 - $350 supplied and installed. Outside the door, for 60 mm to 120 mm, rubber is $400 - $790. Aluminium checker plate outside the door, for 130 mm to 180 mm, is $1,500 - $2,000. A built-in tapered screed, which is the most permanent solution, costs $800 - $2,500 installed.
Can a threshold ramp be used at the front door?
Yes. The front door is one of the most common locations. The key checks are that the ramp does not reduce clear door width below 810 mm, does not compress the weather seal, and has bevelled edges on all sides so it does not create a new tripping hazard for people walking over it.
Is a threshold ramp a building modification requiring a permit?
A removable rubber or aluminium threshold ramp generally does not require a building permit in WA - it is classified as furniture rather than a structural modification. A permanent built-in tapered screed may require notification depending on the local authority's interpretation. Your contractor can confirm what applies in your situation.
When is a threshold ramp a trip hazard rather than a help?
A threshold ramp becomes a hazard when it is too thin to be visible, has square rather than bevelled edges, shifts underfoot because it is not fixed, or is placed on a smooth floor where it can slide. A ramp for steps under 20 mm often creates more hazard than it removes - a built-in screed or level-entry conversion is safer for very small sills.
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