A sliding door frees up the floor space a hinged door needs to swing. That makes it a popular choice for small hallways, ensuites, utility rooms and open-plan spaces. But “sliding door” covers several quite different systems, and the right one depends on your walls, how much privacy you need and how much building work you’re happy to take on.
This guide compares the main internal sliding door systems used in UK homes, so you can narrow down your options before you buy.
The main types of internal sliding door system
1. Pocket door systems
A pocket door slides into a steel or timber cassette built inside the wall. When it’s open, the door disappears completely, leaving a clear opening and both wall faces free for furniture, radiators or artwork.
Good for: small rooms, ensuites, accessibility, and anywhere you want the door to vanish.
Things to know:
- The pocket needs a length of wall roughly equal to the door width beside the opening, and that section can’t contain pipes, cables or sockets that would cross the cavity.
- The kit has to suit your finished wall thickness. Our pocket door wall thickness guide explains 100mm, 115mm and 145mm builds.
- Fitting into an existing wall means opening it up or building a new stud wall, so it’s usually best done during a renovation.
- Fire-rated (FD30) pocket door systems are available, tested as complete assemblies.
Pocket doors come with standard architrave-finished frames or frameless, flush-to-wall versions. Our guide to pocket door frames explains the difference.
2. Surface-mounted sliding doors
A surface-mounted (or face-fixed) system hangs the door from a track fixed to the wall above the opening, so the door slides along the face of the wall. Exposed “barn door” tracks are the best-known style, but there are also discreet systems with a slim aluminium track and cover.
Good for: quick upgrades without structural work, rental properties, and openings where the wall can’t be opened up.
Things to know:
- You need clear wall beside the opening for the door to slide across. Häfele advises that the track should be at least twice the width of the door so the door can slide fully clear of the opening.
- The door overlaps the opening rather than sitting inside it. Häfele recommends an overlap of at least 50mm on each side, so the door is about 100mm wider than the opening.
- Allow space above the doorway for the track. Häfele suggests at least 50mm of wall clearance above the opening for the track and brackets.
- The track carries the full weight of the door, so it must be fixed into studs, a backing batten or solid masonry.
- Because the door hangs in front of the wall, there will be small gaps around it. It won’t seal an opening as well as a hinged door with stops.
- Handles on the wall side need to clear the wall as the door passes. Flush pulls are often used there.
3. Bypass sliding doors
Bypass systems have two or more doors on parallel tracks that slide past each other. You see them on wardrobes and large room dividers. They don’t need a wall pocket or spare wall to one side, but one door always covers part of the opening, so you never get the full width.
Good for: wardrobes, storage, and wide openings where you don’t need a completely clear passage.
4. Telescopic and synchronised systems
For wider openings there are a few specialist variations:
- Telescopic systems have two door panels that slide in the same direction, one behind the other. Eclisse makes telescopic pocket frames that house both panels in a single pocket, which gives a wide opening from one side.
- Synchronised systems link two doors so they move at the same time. Eclisse, for example, offers a synchronisation accessory for its telescopic frames, so both panels move together.
- Double (bi-parting) doors use two doors that meet in the middle, either in two pockets or on a surface track.
5. Glass sliding doors
Glass doors can be used with pocket, surface-mounted and ceiling-mounted systems, usually in toughened glass held by clamps or brackets. They need glass-specific hardware, and you’ll need to think about safety glazing and privacy. Our glass pocket doors guide covers this in more detail.
Side-by-side comparison
| Surface-mounted | Bypass | ||
|---|---|---|---|
| Where the door goes when open | Inside the wall | Across the wall face | Behind the other door |
| Wall space needed | About one door width, inside the wall | About one door width, on the wall face | None beyond the opening |
| Clear opening | Full width | Full width | Partial |
| Building work | Wall must be built or opened up | Track fixed to the wall | Track fixed to the head or ceiling |
| Privacy and sound | Fair, with small gaps | Lower, door sits proud of the opening | Lower, gaps between panels |
| Fire-rated options | Tested FD30 kits are available | Specialist only | Specialist only |
| Hides the hardware | Yes | Track visible unless covered | Partly |
How to choose the right system
Start with the wall
Ask what’s next to the opening. If the wall beside it is a stud wall you can rebuild, or you’re building a new partition, a pocket door is usually the neatest result. If it’s a solid wall you don’t want to open up, a surface-mounted system is the practical route. If there’s no free wall either side, look at bypass doors or a hinged door.
Think about privacy
For a bathroom or bedroom, a pocket door is generally the better sliding option, because it sits within the opening and can take a proper privacy lock. Our guide to pocket doors for bathrooms and ensuites explains locks, gaps and ventilation. Surface-mounted doors work best for kitchens, utility rooms, studies and walk-in wardrobes where a perfect seal doesn’t matter.
Check the door weight
Every track and kit has a maximum door weight. Solid, glazed and oversized doors can be heavy, so check the door spec against the system before ordering. Our pocket door kits list the maximum door size and weight for each kit.
Decide whether you need fire rating
If the door is on a protected escape route, for example after a loft conversion, it may need to be a fire door. A standard sliding door can’t simply be upgraded. You’d need a tested system, such as an FD30 pocket door kit used with a compatible FD30 door. Our guide to FD30 door requirements explains when fire doors are needed at home, and our FD30 pocket doors guide covers the sliding options.
Plan the hardware early
Sliding doors need sliding-door handles. Flush pulls, edge pulls and sliding privacy locks are the usual choice, and soft close stops the door slamming into the frame or pocket. See our pocket door hardware, and our guides to choosing pocket door handles and soft close pocket doors.
Fitting tips for any sliding door
- Measure the finished opening, not the rough one. Account for plaster, linings and flooring.
- Fix the track into something solid. Find the studs or add a backing batten on stud walls, and use the right plugs in masonry.
- Fit the floor guide. It keeps the door running straight and stops it swinging away from the wall.
- Check it’s level. A track that isn’t level can let the door drift open or closed.
- Leave access for maintenance. Choose systems where the track or runners can be adjusted or removed later. Our pocket door installation guide covers this for pocket kits.
Frequently asked questions
Which internal sliding door system saves the most space?
A pocket door, because it disappears into the wall and leaves both wall faces free. A surface-mounted door saves floor space too, but it uses wall space next to the opening.
Can I fit a pocket door without rebuilding the wall?
Not usually. The pocket sits inside the wall, so the section beside the opening has to be built or opened up to take the kit. If that isn’t practical, a surface-mounted system is the usual alternative.
Are sliding doors good for bathrooms?
Pocket doors can work well in bathrooms and ensuites when fitted with a sliding privacy lock. Surface-mounted doors leave larger gaps, so they offer less privacy and sound reduction.
How much wall do I need for a surface-mounted sliding door?
Enough clear wall beside the opening for the door to slide fully clear. Häfele advises a track at least twice the door width, and a door that overlaps the opening by at least 50mm each side.
Can a sliding door be a fire door?
Yes, but only as part of a system tested and certified as a whole, such as an FD30 pocket door kit used with a compatible FD30 door. You can’t make a standard sliding door fire rated by changing the door alone.
Find the right sliding system
Browse our pocket door kits and pocket door hardware, or contact our team for help choosing a system for your opening.
