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Composite Door Lock Replacement Oxford Repairs Same Day
Composite doors are thicker, heavier and more sensitive to the weather than uPVC. We fit correctly sized cylinders, matched multipoint mechanisms and adjust keeps so your door locks smoothly in summer and winter.
Fix my composite door lock
Tell us what you need and we will call you straight back. Calling is quickest: 07520 644 595. Photos by WhatsApp: 07466 695655
Measured for thick doors
Cylinders sized to a 44mm plus slab so they sit flush, not proud of the handle.
Seasonal stiffness fixed
Keeps and hinges set so a door that swells in the sun still locks easily.
Mechanism matched by strip
We measure backset, centres and faceplate length before ordering a gearbox.
New-build doors welcome
Common on Kingsmere, Great Western Park and similar estates around Oxfordshire.
Our composite door lock replacement service in Oxford covers cylinders, multipoint mechanisms, handles and keeps on GRP-skinned composite doors, usually the same day. A cylinder change costs £65 to £85 plus the lock at £25 to £40, and a full mechanism replacement is £85 to £125 plus the mechanism at £65 to £150. In OX1 to OX4 we usually arrive within 10 to 30 minutes.
Many composite door faults are adjustment rather than failure, so we check that first and only replace parts that are actually broken.
How a composite door differs from uPVC
From the street a composite door can look like painted timber, but inside it is a different construction. A typical slab has a glass reinforced plastic (GRP) skin over a timber frame with an insulating foam core, or in some makes a solid timber core. That gives you a door that is noticeably heavier and thicker than a uPVC panel door.
Composite door
Slab usually around 44mm to 48mm thick. Heavy, so hinges and keeps take more load. Darker colours absorb heat and the skin moves with the temperature.
Needs longer cylinders and careful keep setting
uPVC door
A plastic frame with a thinner infill panel. Lighter, and the typical faults are a dropped door or a worn gearbox.
Covered on our uPVC lock page
Both types usually use a euro cylinder and a multipoint locking strip, which is why they get confused. If your door is the white plastic panel kind, our uPVC door lock replacement page is the better guide.
Composite door won't lock? Common causes
| Symptom | Likely cause | Usual fix |
|---|---|---|
| Handle will not lift fully on hot afternoons, fine at night | Skin expanding in the sun, door bowing slightly | Keep and hinge adjustment |
| Key turns but hooks miss the frame | Keeps out of line after the door settled | Reset keeps, no new parts |
| Handle floppy or springs do not return | Worn gearbox or broken handle spring | Handle or mechanism replacement |
| Key will not go in or turn at all | Cylinder fault or snapped key | Cylinder replacement or extraction |
| Door catches the frame at the top | Hinges worn or dropped under the weight | Hinge adjustment or replacement |
| Lock works only when the door is slammed | Seal compressed or keeps set too tight | Keep adjustment |
Do not force the handle
If the handle will not lift, pushing harder on it is the quickest way to break the gearbox. Try pulling the door tight against the seals as you lift, and if it still resists, leave it and call us.
Cylinder sizes for thick composite doors
The single most common mistake we see on composite doors is a cylinder that is too short or too long. Because the slab is thicker than uPVC, the standard sizes stocked in hardware shops often do not fit properly.
- Too short and the key or thumbturn is buried inside the handle, making it awkward to turn.
- Too long and the cylinder sticks out past the outside handle, which leaves it exposed to snapping attacks.
- Offset sizes such as 40/50 or 45/55 are common on composite doors, because the outside and inside handle positions are not equal.
We measure from the centre of the fixing screw to each face of the door furniture, then fit a cylinder that sits flush or within a couple of millimetres. If you want a rated cylinder while we are there, our anti snap upgrade page explains the TS007 3-star and Sold Secure Diamond options, and a straightforward like for like swap is covered under euro cylinder replacement.
Replacing a composite door multipoint lock
Composite doors usually have a multipoint locking strip running down the edge with a central gearbox, hooks or rollers and sometimes deadbolts. When the gearbox wears out, the handle goes floppy or the key stops throwing the hooks.
- Identify the mechanism. We read the maker and model from the faceplate where it is stamped, then measure backset, centres between the handle and cylinder, and the overall strip length.
- Match or replace the gearbox. On many doors only the centre case needs changing. Where the whole strip is worn, we fit a full replacement with the same hook positions so the existing keeps still line up.
- Set the keeps. The new mechanism is only as good as its alignment, so every hook and roller is checked against the frame.
Some composite door makers use their own mechanism, which may need ordering. We tell you on the first visit if that applies, secure the door in the meantime and agree a return date. More on gearboxes generally is on our multipoint lock replacement page.
Composite doors on Oxfordshire new-build estates
Composite front doors are standard on much of the new housing built around Oxford in recent years. We regularly see them on estates such as these:
On newer homes, two issues come up often. First, the door has had a few seasons to settle and the keeps set on handover no longer suit it. Second, the cylinder supplied with the house may be a basic one, so owners use a lock change as a chance to upgrade. Our local pages for Bicester, Didcot and Witney cover travel times and the other doors we see there.
Check your door warranty before any work
New-build and manufacturer guarantees
If your home or door is new, the developer, the new-build warranty provider or the door manufacturer may cover lock and hinge faults for a period, sometimes with conditions about who carries out repairs. Check your paperwork or contact them before booking any independent work, including ours.
If you are outside any guarantee, or the manufacturer cannot attend quickly and you cannot lock the door, we can make it secure and give you an itemised invoice describing the fault and the parts fitted. That record is useful if you later raise the issue with the installer.
For a composite door that has been forced rather than worn, our emergency boarding up and break-in repair service makes it safe first.
Keeping a composite door lock working smoothly
- Lubricate the strip twice a year. A light spray on the hooks and rollers, and a dry lubricant in the cylinder, not thick grease.
- Lift the handle before turning the key. Turning the key against unlifted hooks wears the gearbox and strains the key.
- Watch for seasonal change. If locking gets harder every summer, a small keep adjustment usually solves it for good.
- Keep one good original key. Copy from it rather than from copies, so new keys stay accurate.
Every home lock service we offer, with prices, is listed under locksmith services in Oxford. For simple habits that cut the risk of a lockout, our guide on avoiding getting locked out again is worth five minutes.
Composite door lock prices in Oxford
Labour and VAT are included, parts are listed separately and the price is agreed before we set off.
| Service | Price | What's included |
|---|---|---|
| Front/back door lock change (euro cylinder) | £65 to £85 + lock £25 to £40 | Cylinder sized to your door, 3 keys |
| Anti-snap cylinder upgrade (TS007 3-star) | £95 to £135 + cylinder £50 to £120 | Rated cylinder for the main entrance |
| uPVC multipoint mechanism replacement | £85 to £125 + mechanism £65 to £150 | Also applies to composite door gearboxes and strips |
| uPVC door adjustment (dropped/misaligned) | £65 to £95 | Keep and hinge setting on composite doors too |
| Door handle replacement | £55 to £85 + handle £25 to £60 | Floppy or broken handles |
| Lock repair | £55 to £85 | No fix, no fee |
Prices include VAT and labour. Parts are listed separately. See the full Oxford locksmith price list.
