Threshold & Transition Calculator — Strips & Profiles

T-bar profiles suit floors at the same level. Reducer profiles handle height differences up to 12mm. Ramp/end profiles cover the edge where flooring meets bare subfloor. Stair nosing covers step edges.

Standard UK internal doors are 762mm wide, so a 900mm strip covers the full doorway with trim overlap. For double doors, use an 1800mm strip. Strips can be cut to exact width.

Screw-down strips are most secure and suitable for high-traffic areas. Self-adhesive strips are easier to fit but less durable. For underfloor heating zones, adhesive avoids screwing into pipe zones.

Aluminium is the most durable and suits any height difference. PVC/plastic strips are cheaper but only suit small height differences. Brass and stainless steel offer premium finishes.

Approved Document M (access to and use of buildings) requires accessible thresholds to be level or, where a raised threshold is unavoidable, no more than 15mm total height — with any upstand higher than 5mm chamfered or rounded to ease wheelchair and mobility access. It does not mandate a strip over every join; the rule is about keeping the threshold low and its edges eased on accessible routes.