Should I replace just the slats on my roller garage door, or replace the whole thing? Replacing individual slats is sensible when 1-3 slats are damaged on an otherwise sound curtain less than 8 years old, and total parts cost stays under £150. Replace the whole curtain (or the whole door) when over 4 slats are damaged, the side guides are corroded, the drum bearings are noisy, or the door is older than 12 years. UK replacement slats start at around £15 each (55mm) and £22 each (77mm); a complete made to measure DIY roller door from TWF starts at £620 and includes a 5-year warranty.
The 3 things to check before you buy replacement slats
Most botched slat replacements happen because the buyer ordered the wrong slat size, the wrong end lock type, or the wrong colour run. Run these three checks first.
1. Slat profile size (55mm or 77mm)
UK domestic roller garage doors come in two standard slat profiles, and they are not interchangeable between curtains. If your existing door uses 55mm slats, you cannot swap to 77mm without also changing the side guides, drum, and motor, at which point you are buying a whole new door. Measure the height of one slat (top of one curve to the top of the next) with a steel rule.
2. End lock type
Each slat has a plastic end lock that holds it in the side guide. End locks vary by manufacturer, some are Securoglide pattern, some are Garador, some are TWF, and the wrong end lock will jam in the guide. Pop one slat out at the bottom and take a photo of the end lock from both sides; any reputable UK slat supplier can match it.
3. Colour and finish
A single replacement slat in a slightly different RAL shade is more visible than you would think, especially on dark colours that have weathered. Order the slat in the same RAL number as the original curtain. If the original is more than 5 years old, expect mild colour drift; getting all replacement slats from the same production batch helps.
55mm vs 77mm: how to tell which slat you have
| Feature | 55mm slat | 77mm slat |
|---|---|---|
| Slat height (curve to curve) | 55mm | 77mm |
| Typical use | Doors up to ~3m wide | Doors over 3m wide, larger openings |
| Insulation foam thickness | ~14mm | ~20mm |
| Slat strength rating | Standard | Heavy duty |
| Replacement cost per slat (UK 2026) | From £15 | From £22 |
| Compatible TWF lock | TWF55 auto lock | TWF77 auto lock |
| Compatible TWF curtain | 55mm Silver / Gold | 77mm Silver / Gold |
If your slats are not 55mm or 77mm, you may have a non standard or imported curtain. Measure twice and check with the original installer before ordering UK replacements, the profiles do not match.
Step by step: replacing 1-3 damaged slats yourself
This procedure works for most insulated UK roller doors with plastic end locks. Allow 90 minutes for the first slat, 30 minutes for each subsequent one. You will need: replacement slats, a flat blade screwdriver, soft faced mallet, a friend to hold the curtain, and a step ladder if your door is over 2.4m tall.
Step 1: Wind the door fully down and disconnect power
Bring the curtain to its fully closed position so the damaged slats are at the bottom and reachable. Cut power at the consumer unit. If you cannot wind it down because the motor has failed, use the external manual override kit, never work on a roller curtain that is partly wound around the drum.
Step 2: Identify the slats to replace
Mark the damaged slats with chalk or low tack tape. Count their position from the bottom (slat 1 is the bottom rail, slat 2 is above it, etc) so you can order matching replacements without dismantling the whole curtain.
Step 3: Remove the bottom rail (T section)
The bottom rail screws into the lowest slat at each end. Undo the two end screws and slide the bottom rail out sideways. Keep the screws, they are usually a non standard size and replacements are awkward to source.
Step 4: Push out the end locks
With the bottom rail removed, the lowest slat can slide sideways out of the guide. Push the end locks inward (towards the centre of the curtain) using a flat screwdriver, then slide the slat out. Repeat for each damaged slat. The end locks usually come away with the slat, keep them; you may be able to reuse them on the new slat.
Step 5: Fit the replacement slats
Slide the new slat in from the side, with end locks loose. Align it with the slat above (the curve profiles must mate cleanly). Once positioned, push the end locks outward into the side guides. The slat should now hang in the curtain naturally.
Step 6: Refit the bottom rail
Slide the bottom rail back across the lowest slat and refit the two end screws. Check the rail is square, if it is twisted, the door will catch as it closes.
Step 7: Test before powering up
Wind the door up by hand half a turn and let it back down. Check the new slats engage cleanly in the guides. If anything snags, do not power on, diagnose first. Once the manual test is clean, restore power and run the door once up and once down.
Slat replacement vs full door replacement: cost comparison
| Scenario | Slat replacement cost | Full door replacement cost | Better value? |
|---|---|---|---|
| 1-3 damaged slats, door under 8 years | £45-£90 parts + DIY | £620+ DIY / £1,100+ fitted | Slat replacement |
| 4-6 damaged slats, door under 8 years | £90-£180 parts + DIY | £620+ DIY / £1,100+ fitted | Slat replacement (just) |
| 4+ damaged slats, door 8-12 years | £90-£180 parts + DIY | £620+ DIY / £1,100+ fitted | Borderline, assess corrosion |
| Any slats, door over 12 years | £45-£180 parts | £620+ DIY / £1,100+ fitted | Full replacement |
| Slats damaged + corroded side guides | £45+ parts + £150+ guides | £620+ DIY / £1,100+ fitted | Full replacement |
| Slats damaged + noisy drum bearing | £45+ parts + £200+ motor labour | £620+ DIY / £1,100+ fitted | Full replacement |
If your numbers are within £150 of a full DIY door, replace the whole thing. You get a fresh 5-year warranty, current insulation standards, and a known good motor, none of which a slat repair gives you.
When to replace the whole door instead
Four scenarios where a slat repair is false economy:
- Side guides are corroded or pitted. New slats will run rough in worn guides and wear faster. Replace the door.
- The motor has been making noises for over a month. A failing tubular motor is £140-£260 to replace plus 1-2 hours labour. Bundling that with new slats often costs more than a full DIY door.
- The door is over 12 years old. UK insulation standards have moved on (current TWF doors achieve thermal performance the 2014 generation does not). The whole door payback in heating savings is real if your garage is integral.
- You can see daylight along the side guides when the door is closed. The curtain has lost its seal, slats will not fix that.
If you are on the fence, work through the repair or replace decision guide, then get an instant made to measure DIY price from the configurator to compare against your slat repair total.
Frequently asked questions
How much does it cost to replace a slat on a roller garage door in the UK?
Individual replacement slats cost from £15 (55mm profile) or £22 (77mm profile) each in 2026. Add £5-£10 per slat for new end locks if the originals are damaged. A typical 2-3 slat repair comes in under £100 in parts. If you are paying a fitter, expect £80-£120 callout plus parts.
Can I replace just one slat, or do I have to replace the whole curtain?
You can replace any number of individual slats provided they are the same profile (55mm or 77mm) and end lock pattern as the rest of the curtain. The slats slide in and out of the side guides individually, so a single slat replacement is genuinely a single slat job.
Are 55mm and 77mm slats interchangeable?
No. The profiles are different and they ride in different size guides. If your door has 55mm slats, you must replace with 55mm. Switching profile size means replacing the whole curtain, both side guides, and (usually) the drum and motor as well, at which point a new door is cheaper.
How long do roller garage door slats last?
UK slats typically last 15-20 years with normal use, longer if you avoid hitting the door with a vehicle. The most common failure modes are crash damage (immediate), bottom slat corrosion from puddle water (5-10 years for cheap doors, 10-15 for premium), and end lock fatigue (10+ years).
Do I need to lubricate new replacement slats?
The slats themselves do not need lubricating, but the side guides do. After fitting new slats, run a light bead of white lithium grease down each guide. This is also the ideal moment to do an annual service, refer to the maintenance section in the TWF roller door repair team’s standard schedule.
Can I replace slats on a Securoglide, Alluguard, Garador or Hörmann roller door?
Yes, provided you order slats with the matching profile (55mm or 77mm) and end lock pattern. UK slat profiles are standardised by size, so a 55mm slat from one supplier fits a 55mm door from any other manufacturer if the end locks match. Take a photo of your existing slat and end lock when you order.
What if my door has been wound unevenly inside the drum?
Stop trying to operate it. Unwinding a tangled curtain requires the housing to come off and is not a DIY job, slats will buckle or kink permanently if you force the motor against them. The TWF roller door repair team can untangle a drum and assess any slat damage in the same visit, typically £150-£250.
How do I know if my slats are insulated?
Cut into a damaged section if you have one (or look at the cross section of the slat from the side). Insulated slats are filled with closed cell PU foam, typically white or off white. Non insulated slats are hollow aluminium. Most UK roller doors sold since 2015 are insulated as standard.
Sources and further reading
- MoneySavingExpert forum thread Replacing Slats in Roller Garage Door (forums.moneysavingexpert.com)
- BS EN 13241, Industrial, commercial and garage doors specification
- BS EN 12453, Safety in use of power operated doors
- Door & Hardware Federation (DHF) UK Code of Practice TS 011
- Garage Door Parts UK and AvosDim slat compatibility specifications
This guide was reviewed by the TWF roller door specialist team. Last updated April 2026. If you are unsure of your slat profile or end lock pattern, send a photo of one slat and one end lock to the TWF roller door repair team for a free identification.
