Composite Door Dropped or Bowed? Fix It Before You Replace It

A composite door that scrapes the frame, needs a shoulder to close in July, or shows daylight at one corner has not failed — it has moved. The slab is heavy, the hinges settle, and dark skins expand in direct sun. Almost all of it is adjustable, and almost none of it means a new door.

Why composite doors drop

A 44–48mm composite slab with glazing is one of the heaviest things hanging in your house. Flag hinges settle under that weight — first a scuff line at the bottom corner, then a door you lift by the handle to lock at night. Left alone, every lift strains the gearbox, and the £0-parts adjustment quietly becomes a £180 mechanism job. The full symptom map is on our composite door repairs page.

The bowing panic — and what’s actually happening

Dark composite doors on south-facing walls reach 60–70°C skin temperature in direct sun. The skin expands, the core doesn’t, and the slab bows away from the frame — locks fine in the morning, sticks by mid-afternoon, behaves again at night. That daily rhythm is the giveaway: it’s thermal movement, not a broken door.

The fix is compression: keeps and hinges adjusted so the locking points still land when the slab is at its summer worst. It’s the same principle as the hinge adjustment on any heavy door — done once, properly, it holds.

What never to do

Never let anyone plane a composite door. A timber door forgives a planer; a composite door’s GRP skin doesn’t — cutting it exposes the core, invites water, and voids the manufacturer’s warranty in one stroke. If a trader suggests it, that’s your cue to close the door (gently) and call someone else.

What it costs

Hinge and keep realignment is an £85 flat visit — most dropped and bowed doors need no parts at all. If the door has been forced for months and the gearbox has paid the price, a genuine replacement runs £20–£180 in parts on the same visit. A new composite door runs £1,100–£2,500 fitted. Full numbers live on the transparent price guide.

When replacement is genuinely right

A slab with long-term water damage in a timber core, or a severe permanent bow that adjustment can’t chase, is a replacement conversation — and if that’s what Max finds, that’s what he’ll say. It’s rare. If the door is jammed shut right now, non-destructive entry comes first, verdicts second.

Quick answers

My composite door has bowed — is it ruined?

Almost never. A slight bow on a dark or south-facing door is thermal movement, managed with keep and compression adjustment. A severe permanent bow on a newer door is a manufacturer warranty matter — and an honest locksmith will tell you which one you have before charging you.

Can a composite door be planed like a timber door?

No. Planing cuts the GRP skin, exposes the core and voids the warranty. All alignment work on a composite door happens at the hinges and keeps.

What does fixing a dropped composite door cost in Nottingham?

Hinge and keep realignment is an £85 flat visit — no parts. Compare that with £1,100–£2,500 for a replacement door and the maths does itself.