Sliding Patio Doors

Sliding doors use large panels running on rollers within a multi-track frame. A two-panel door has one fixed and one sliding panel, while three or four-track systems let several panels stack behind each other for a wider opening. Panels can also slide into a wall pocket on some systems.

Because sliding panels are bigger and have fewer frames than bifold doors, they show fewer and slimmer sightlines when closed. Slimline aluminium systems can have very narrow interlocks between panels, which keeps the view across a garden as clear as possible. The trade-off is that one panel always remains in the opening.

Lift-and-slide doors raise the panel off its seals when the handle is turned, so it glides easily, then lower it back onto the gaskets when closed. This allows very large, heavy panels with good weather sealing. Standard in-line sliders are lighter, simpler and usually cost less.

Older patio doors with worn rollers often feel heavy and grind along the track. Modern sliding doors use adjustable stainless or sealed bearing rollers designed for heavy glass, but they still need a clean, level track. Grit in the bottom track is the main reason a sliding door becomes stiff.

Sliding door panes reach near the floor, so they need safety glass. In England, Approved Document K treats glass in doors, and in side panels within 300mm of a door's edge, up to 1500mm from the floor as critical. Toughened glass is standard; laminated adds security and holds together if broken.

In England, a replacement door with more than 60% of its internal face glazed should achieve a U-value of 1.4 W/m²K or a Doorset Energy Rating of band C under Approved Document L. Large sliding doors in new extensions are assessed within the extension's energy calculations.

Security on sliding doors depends on multi-point hook locks that grip the frame, anti-lift blocks that stop panels being lifted off the track, internally glazed beads and an anti-snap cylinder. Older patio doors without anti-lift protection can sometimes be lifted out, so ask whether the system is tested to PAS 24.

Sliding doors can have a raised sill for weather resistance or a low, flush track for near level access between floor and patio. Flush tracks need good drainage outside and some shelter, and on exposed elevations a slightly raised threshold usually keeps water out more reliably.

The cost of sliding patio doors depends on the opening size, the number of panels and tracks, aluminium or uPVC, standard or lift-and-slide hardware, colour, glass and threshold. Very large panels may need lifting equipment. See the guide prices for typical ranges; the written quote fixes your figure.

Replacing patio doors in the same opening usually takes about a day on site, longer for wide multi-panel systems or where heavy glass needs extra hands or lifting gear. The doors are made to the survey sizes first, and the lead time is confirmed in writing with the quote.

Keep sliding doors running smoothly by vacuuming the bottom track and drainage slots regularly, wiping the tracks with a damp cloth and checking the brush seals. Avoid oil on the track itself, which attracts grit. Rollers can be adjusted when a panel starts to drag or the lock no longer lines up.

Making an opening wider for new sliding doors is structural work that needs building control approval and a correctly sized lintel or steel. Replacing doors in the existing opening is simpler. Flats, listed buildings and conservation areas may also need planning or other consent for the change.