What we mean by “dropped”
A commercial aluminium door is “dropped” when it no longer sits true in its frame. The bottom rail drags on the floor or threshold, the top of the door tilts away from the head frame, or the latch and strike no longer meet cleanly. Sometimes you can see it; more often you hear it first — a soft scrape on opening, a clunk on close, a refusal to latch unless lifted.
A dropped door is one of the most common faults across the UK aluminium-shopfront fleet, and the cause is almost always wear in one of three pivot-related components. The door itself, the frame and the glazing are almost never the problem.
The three components that cause a drop
Aluminium doors pivot on three hardware items working together: the bottom pivot bolted into the floor, the top centre bolted into the head of the frame, and the transom closer that controls the door’s closing speed and final latch. Wear in any of these lets the door drift out of alignment.
- Bottom pivot — a hardened spindle bolted into the floor, with a bush in the door’s bottom rail. Carries the full weight of the door. Worn pivots show as scrape marks at the threshold and a drag at the hinge edge.
- Top centre — the upper pivot, usually with a bearing or bushing. Wear shows as the door tilting away from the frame at the top, and a clunk when opening or closing.
- Transom closer — concealed inside the metal transom (the horizontal bar at the top of the frame). When the closer’s internal hydraulic seals fail and fluid leaks out, the door slams or fails to close, putting uneven load on the pivot and accelerating its wear.
How an engineer diagnoses a dropped door
Diagnosis takes a couple of minutes on site, and often it can be done remotely from one decent photograph and a 10-second video of the door opening and closing. We look at four things.
First, where is the door dragging? A scrape mark on the threshold under the bottom rail tells us the pivot has lost height. A scrape on the latch side means the door has rotated about a worn top centre. Second, can we see fluid on the floor under the transom or on top of the door? That’s closer failure — the seals are gone. Third, let the door go from open: does it close at a controlled speed and latch cleanly, or does it slam or stop short? Fourth, with the door at rest, can you rock the top of the door 5–10mm in or out of the frame? Wear in the top centre.
Almost every dropped-door callout is one of these four diagnostics in some combination. From the photo and video we can usually be on site with the right parts on the first visit.
The repair, walk-through
A bottom pivot replacement is the most common job. We support the door open, remove the floor cover plate, undo the pivot fixing bolts, slide the door clear, lift the pivot out, drop in a new one, set the height, refit the cover plate, swing the door back into the bush in the bottom rail, and check the close. Typically 1–2 hours on site for a like-for-like.
A top centre is similar at the head of the door. Undo the cover, swap the pivot insert, re-engage the door, check the rotation. Usually around an hour.
A transom closer replacement is the bigger job — we remove the transom cover, disconnect the closer arm, drop the old closer out, slot a new one in, reconnect the arm, set the closing and latch speed, refit the cover. Typically a half day, and for high-traffic doors we schedule out-of-hours so the door stays in service during business hours.
What it costs and how long it lasts
A bottom pivot or top centre is typically £200–£400 including labour for a single door, depending on the brand, finish and any access constraints. A full transom closer replacement runs higher — closer to £500–£900 — because the closer itself is the most expensive part.
Done correctly, a replacement pivot lasts 5–10 years on a normal-traffic door. High-traffic retail doors burn through pivots faster — 3–5 years is more typical, especially if the closer is set too aggressively and the door slams.
Preventing the next drop
The closer is the single most important component for keeping the pivot alive. A correctly-tuned closer brings the door home with a controlled speed and a definitive latch — no slamming, no bouncing back. The cheapest preventative measure on any commercial aluminium door is a five-minute closer adjustment every six months.
For high-traffic sites — shopping centres, retail parks, hospitality venues — a maintenance contract that covers six-monthly closer adjustment and annual pivot inspection typically pays for itself the first time it catches a worn pivot before the door starts dragging.