Standard (in-line) sliding door
Two or more sashes on parallel tracks, the most economical system. Brush or EPDM seals and adjustable rollers. Suits apartments, balconies and interior partitions with panels up to about 100 – 150 kg.
Door systems
Aluminium Sliding Door Systems
An aluminium sliding door system is a set of extruded frame and sash profiles, tracks, rollers, locks, seals and glazing that lets large glass panels slide past each other instead of swinging open. Types range from simple two-panel balcony doors to heavy lift-and-slide and multi-track stacker doors spanning a whole façade. Metline supplies sliding door profiles, thermal-break sections, tracks and hardware to door fabricators for residential and commercial projects worldwide.
- Profile alloy
- 6063-T5 / T6, 6061-T6 for heavy parts
- Types
- Standard, lift-and-slide, stacker, slim
- Sash weight
- Up to about 400 kg (lift-and-slide)
- Standards
- EN 14351-1 · AAMA/WDMA/CSA 101
How an aluminium sliding door works
A sliding door has a fixed outer frame with two or more tracks. Sashes (the moving glazed panels) ride on rollers in the bottom track and are guided at the head. Because the panels never swing into the room or onto a balcony, sliding doors save floor space and can be made far larger than hinged doors, which is why they dominate patios, balconies and wide openings.
Aluminium is the material of choice for this job because its strength and stiffness let the frame stay narrow while carrying heavy double or triple glazing. A 6063-T5 or T6 extrusion can include the roller channel, screw ports, seal grooves, glazing pockets and a polyamide thermal break in one profile, which timber and uPVC cannot match at the same sightlines.
The quality of a sliding door depends less on the glass than on four parts: the frame and sash profiles, the rollers and track, the interlock and seals where the panels meet, and the locking hardware. Get those right and the door slides with a light push for decades; get them wrong and it leaks, whistles in the wind and drags on worn rollers.
Types of aluminium sliding door
Lift-and-slide door
Turning the handle lifts the sash off its compressed seals onto heavy rollers; lowering it clamps the seals back. That gives far better air and water tightness than a standard slider and allows sashes of around 300 – 400 kg on heavy-duty hardware.
Multi-track stacker door
Three to six tracks so all moving panels stack behind one fixed panel, opening two-thirds or more of the width. Common in villas, hotels and restaurants.
Pocket sliding door
Panels slide into a cavity in the wall, leaving the opening fully clear. Needs the wall to be designed around the pocket and good drainage of the concealed track.
Slim-frame sliding door
Interlock sightlines of around 20 – 40 mm and concealed outer frames for a nearly all-glass look. Uses stiffer profiles, often steel-reinforced interlocks, and precise hardware. See slimline doors.
Commercial and automatic sliders
Heavier sections, safety glazing and motor operators for shop entrances, offices and public buildings. See commercial doors.
Common opening layouts
| Layout code | Panels | Opening | Typical use |
|---|---|---|---|
| XO / OX | 1 sliding + 1 fixed | About 50 % | Apartment balconies, small patios |
| XX | 2 sliding | About 50 %, either side | Interior partitions, wardrobes |
| OXXO | 2 sliding centre + 2 fixed | About 50 % in the middle | Wide living rooms with a central opening |
| XXX (3-track) | 3 sliding on 3 tracks | About 67 % | Villas, terraces |
| XXXX / 4-track | 4 or more stacking panels | 75 % or more | Hotels, restaurants, large terraces |
| Corner (90°) slider | Two runs meeting with no corner post | Opens the corner completely | Premium homes and resorts |
X = sliding panel, O = fixed panel, viewed from outside by North American convention. Confirm the viewing side on drawings, because conventions differ by country.
Typical profile and performance parameters
Figures below are typical ranges for current residential and light-commercial systems. Actual values depend on the specific system, panel size and test report, so always check the declared performance for the size you are ordering.
| Parameter | Standard slider | Lift-and-slide / premium |
|---|---|---|
| Profile alloy and temper | 6063-T5 | 6063-T6; 6061-T6 or steel for reinforcing interlocks |
| Frame depth | 70 – 120 mm | 116 – 200 mm (thermally broken) |
| Profile wall thickness | 1.4 – 2.0 mm | 2.0 – 2.5 mm on load-bearing parts |
| Thermal break | Optional | Polyamide strips 15 – 35 mm |
| Maximum sash weight | About 80 – 150 kg | About 250 – 400 kg, higher with special hardware |
| Glazing | 5 – 24 mm single or double | 24 – 52 mm double or triple |
| Frame U-value (Uf) | About 5 – 7 W/m²K without break | About 2.0 – 3.5 W/m²K |
| Air permeability (EN 12207) | Class 2 – 3 | Class 3 – 4 |
| Water tightness (EN 12208) | Class 3A – 5A | Class 7A – E750 and above |
| Wind resistance (EN 12210) | Class B2 – C3 | Class C3 – C5 |
Whole-door U-value (Ud) is calculated per EN ISO 10077 or NFRC 100 and depends mainly on the glass; a thermally broken frame with Low-E double glazing typically reaches roughly 1.4 – 2.0 W/m²K.
Profiles, alloys and thermal breaks
| Component | Material | Why |
|---|---|---|
| Outer frame and sash | 6063-T5 or T6 extrusion | Smooth surface for coating, accurate thin-walled sections |
| Interlock and meeting stiles | 6063-T6 or 6061-T6, sometimes steel-reinforced | Must resist wind bending over the full door height |
| Bottom track | 6063-T6 with stainless steel or aluminium running rail | Wear resistance under rollers |
| Thermal break | Glass-fibre reinforced polyamide PA66 GF25 | Low conductivity, expansion close to aluminium |
| Rollers | Stainless steel or sealed bearing tandem rollers | Carries sash weight; must be adjustable |
| Seals | EPDM gaskets, silicone-treated brush pile with fin | Air and water tightness |
6063 dominates door profiles because it extrudes at high speed into complex hollow sections with a fine surface finish. Its typical T6 yield strength of about 214 MPa (specified minimum around 170 MPa) is ample for frames. For very tall doors the governing check is stiffness, not strength: the interlock must not deflect more than about L/175 under design wind load, so section depth matters more than alloy choice. See 6063 extrusions.
Glass, locks and seals
Safety glass
Glass in doors must be safety glazing: toughened or laminated to EN 12600 in Europe, 16 CFR 1201 / ANSI Z97.1 in the US, AS 1288 in Australia.
Insulating glass units
Typical double units are 5 + 12 to 16 mm cavity + 5 mm with a Low-E coating and argon fill; triple units are used in cold climates.
Acoustic and security glass
Laminated glass with acoustic interlayer cuts traffic noise; laminated inner panes also resist forced entry.
Locking
Hook locks engage the interlock; multi-point locks add security on large panels. Lift-and-slide handles lock automatically when lowered.
Low threshold
Recessed or flush tracks give step-free access but need careful drainage design to keep water out.
Insect screens
Sliding or pleated screens can run on an extra track. See screen doors.
Performance standards and codes
| Region | Product standard | What it covers |
|---|---|---|
| Europe / UK | EN 14351-1 with EN 12207, EN 12208, EN 12210 | CE / UKCA declaration: air, water, wind, thermal, acoustic, safety |
| North America | AAMA/WDMA/CSA 101/I.S.2/A440 (NAFS); NFRC 100/200 | Performance class (R, LC, CW, AW) and grade; U-factor and SHGC labels |
| Hurricane zones | ASTM E1886 / E1996, Florida Building Code | Impact and cyclic pressure tests |
| Australia | AS 2047 | Windows and external glazed doors, water and wind ratings |
| Profiles | EN 755-2, EN 12020, ASTM B221 | Mechanical properties and tolerances of the extrusions |
| Coatings | Qualicoat, AAMA 2603/2604/2605, EN ISO 7599 | Powder coating and anodising quality |
How sliding doors are typically specified
- Coastal villa patio: four-track lift-and-slide door around 6 m wide, thermally broken frame, Low-E laminated double glazing and marine-grade pre-treated powder coat.
- Apartment balcony: two-panel OX standard slider with a low threshold, toughened double glazing and an integrated insect screen.
- Hotel guest rooms: repeated lift-and-slide units with acoustic glass, child-safe restrictors and one finish across all floors.
- Office meeting rooms: slim-frame interior sliders with single laminated glass for flexible partitions.
- Restaurant frontage: multi-track stacker opening most of the façade to a terrace in good weather.
How to order sliding door profiles from Metline
- Door scheduleOpening sizes, layout code, quantity, location (ground floor, high-rise, coast) and any code or test requirement.
- System selectionStandard, lift-and-slide, stacker or slim; thermal break; glass make-up; threshold type; hardware and colour.
- Shop drawingsElevations, sections and cutting lists for approval, or supply to your own system drawings.
- InspectionProfile dimensions, coating thickness and hardware checks; EN 10204 3.1 mill certificates for extrusions.
- DeliveryProfiles in bundles or cut to size, with hardware boxed by door, export-packed, on EXW, FOB, CIF or DAP terms.
References and standards
- EN 14351-1 – Windows and doors: product standard, performance characteristics
- AAMA/WDMA/CSA 101/I.S.2/A440 – North American Fenestration Standard
- NFRC 100 – Procedure for determining fenestration product U-factors
- EN 755-2 – Extruded rod/bar, tube and profiles: mechanical properties
- ASTM B221 – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
Aluminium (aluminum) sliding doors: FAQ
What is the difference between a sliding door and a lift-and-slide door?
A standard slider runs on rollers with brush or light gasket seals at all times. A lift-and-slide door lifts the sash off compressed seals when the handle is turned and clamps it down when closed, giving much better air and water tightness and allowing far heavier panels.
How large can an aluminium sliding door panel be?
Standard sliders usually carry panels of up to about 100 – 150 kg. Heavy lift-and-slide systems are commonly rated to about 400 kg per sash, which allows glass panels around 3 m high and 3 m wide depending on glass thickness.
Are aluminum sliding doors energy-efficient?
With a polyamide thermal break, Low-E insulating glass and good seals, whole-door U-values of about 1.4 – 2.0 W/m²K are typical. Non-thermally broken frames are suitable only for mild climates or interior use.
Which alloy is used for sliding door profiles?
6063 in T5 or T6 temper for almost all frames and sashes, because it extrudes cleanly and coats well. 6061-T6 or steel inserts are sometimes used in interlocks of tall doors that need extra stiffness.
Can sliding doors have a flush threshold?
Yes, many systems offer recessed tracks for step-free access. The track must drain to the outside or into a channel, and exposed locations usually need a canopy or a slightly raised sill to keep water tightness.
What do you need for a sliding door quotation?
Opening sizes, layout, quantity, door type, glass specification, finish, required performance or code, and delivery destination. Architectural drawings make pricing faster and more accurate.
Specifying sliding doors?
Send your door schedule, glazing and finish requirements to sales@metline.in. We will return a profile proposal and a delivered price.
