Pocket doors are one of the smartest space-saving upgrades you can make to an internal room, and a good pocket door kit is what makes the job achievable on site. Instead of swinging into the room on hinges, the door slides sideways into a hollow pocket built inside the stud wall, so the floor area a hinged door would sweep through is handed straight back to you. This guide explains how a pocket door kit works, what the new Frelan Hardware range includes, the sizes and weights it suits, and how to choose between a single and a double set-up.

Supplied by Trade Door Handles, trusted UK supplier of architectural ironmongery since 1976, with quick nationwide delivery.

A pocket door kit is a complete concealed sliding system: the cavity frame, track, hangers, soft-close mechanism and fixings needed to hang one internal door so it slides neatly out of sight. Rather than buying the frame, gear and track separately, the pocket door kit brings the whole assembly together in a single box, which keeps specification simple and cuts the risk of mismatched parts on site. The Frelan pocket door gear range is built for standard timber stud construction, so it drops into most partition walls without special detailing.

The door hangs from wheeled hangers that run along a track fixed inside the head of the frame. As the door is pushed open it travels sideways into the wall cavity, disappearing between the two faces of plasterboard. When closed, it fills the opening like any other door. The soft-close and soft-open mechanism fitted to every Frelan pocket door kit takes over in the last few centimetres of travel, drawing the door gently to a stop so there are no bangs, slams or trapped fingers.

Because it reclaims the swing of a hinged door, a pocket door kit is ideal wherever floor space is tight or an opening needs to feel generous. Common uses include:

• Bathrooms and en-suites, where a swinging door clashes with sanitaryware
• Utility rooms, pantries and boot rooms with limited clearance
• Home offices and studies carved out of a larger room
• Tight hallways and landings where a door would block circulation
• Open-plan layouts that need to be divided occasionally but usually stay open

The range from Frelan Hardware is deliberately compact: a single-door kit, a double-door kit and an adaptor that links two singles together. That means one decision to make rather than a catalogue to wade through. You can view the full line-up in our pocket door hardware collection, and every technical figure below comes from the manufacturer's own Frelan pocket door brochure.

The single pocket door kit is the core product and the one most projects need. It carries one internal door of up to 2040mm high, 860mm wide and 44mm thick, and is rated for doors weighing up to 100kg. It arrives with the soft-close and soft-open action fitted as standard, is adjustable on site, and is cycle tested to 100,000 operations. Step-by-step guidance is set out in the single pocket door fitting instructions.

The double pocket door kit handles a pair of doors that meet in the middle of a wide opening, with each leaf sliding into its own cavity. It contains two single kits plus the joining adaptor, so everything needed for the pair is supplied together. Each leaf keeps the same 100kg rating, soft-close action and on-site adjustability as the single. The matching double pocket door fitting instructions cover the extra steps for aligning two leaves.

The adaptor is the joining component that turns two single kits into one coordinated double system. It is the right choice if you have already bought, or are buying, two single kits and simply need the part that links them. If you are starting from scratch, the ready-packaged double pocket door kit is usually the simpler and better-value route, because it already includes the adaptor.

Getting the wall and the door right is the key to a smooth installation, so it pays to check the numbers before you order a pocket door kit. The whole range shares the same core specification.

• Maximum door size: 2040mm high x 860mm wide x 44mm thick (per leaf)
• Maximum door weight: 100kg per leaf
• Suitable door thickness: 30-45mm; 35mm doors with raised beading or mouldings are fine provided the overall thickness stays within 45mm
• Cycle tested: 100,000 opening and closing operations
• Material: anodised aluminium frame with natural pine timber liners
• Guarantee: 5 years against manufacturing defects

Each pocket door kit is designed for standard 4 x 2 (89mm) stud work with 12.5mm plasterboard, which gives a finished wall thickness of 114mm and an internal cavity of 57mm to suit 30-45mm doors. One track size covers every door width in range, and the track is clearly marked to show the fitter where to cut for common sizes. This makes the pocket door kit adaptable on site rather than made-to-measure.

Two points are worth flagging early. First, finishing jambs and brushes are not included: the jambs are made up by the fitter on site, which keeps the kit flexible but means allowing a little joinery time. Second, the Frelan pocket door kit is intended for internal use in residential and light commercial settings and is not suitable for fire-rated door installations. Doors are always sold separately, so you are free to match the pocket door kit to any suitable door you like.

A pocket door kit is not the only way to save space at a doorway, so it helps to see where it wins and where a different approach might suit.

A surface-mounted sliding or barn door runs along the face of the wall on show, which is a strong design statement but still needs a clear stretch of wall beside the opening and offers less sound and privacy separation. A pocket door kit hides the door completely inside the wall, so nothing is on display and the adjacent wall stays usable for furniture, switches or radiators.

A bi-fold folds back on itself and still projects into the room, and the folding leaves reduce the clear opening width. A pocket door kit gives you the full opening with nothing protruding, which is why it is often the tidier answer for bathrooms, utility rooms and other tight spaces.

Use this quick checklist to specify with confidence:

1. Count the leaves. One door means a single kit; two doors meeting in the middle means the double pocket door kit (or two singles plus the adaptor).
2. Check the door. Confirm it falls within 2040 x 860 x 44mm, weighs no more than 100kg and is 30-45mm thick.
3. Check the wall. Make sure you can build a 4 x 2 stud partition to house the cavity, or plan one into the works.
4. Allow for the jambs. Remember the fitter forms the finishing jambs, and order the door separately.
5. Rule out fire doors. If the opening needs a fire-rated door, this pocket door kit is not the right product.

For a project that needs matching handles, hinges and wider ironmongery, the Frelan Hardware and Burlington Hardware collections sit alongside the pocket door gear range at Trade Door Handles.