Ultra-slim sliding doors.

The ultra-slim variant is a different extrusion to the standard sliding system, not a tighter version of the same one. The interlock profile is reworked to reduce the visible aluminium at the meeting rail; the perimeter extrusions are adjusted to match. Glass build-up, hardware sizing, and weather sealing follow the same engineering principles as the standard range — what changes is the visible frame.

It is competitive with steel-look minimal-frame sliding doors on sightline alone, with the substantial advantage that the frame is properly thermally broken aluminium. Steel-look systems achieve their thinness by accepting a higher U-value (because steel is thermally conductive); ultra-slim aluminium hits a similar visible result without the thermal compromise.

There is a real trade-off in the other direction. The ultra-slim profile has slightly less stiffness against wind load on the largest panel sizes, which means our maximum panel size on the ultra-slim variant is smaller than on the standard system. For openings that need both maximum size and minimum sightline, we sometimes recommend a hybrid — ultra-slim profile on the visible interlocks, standard profile on the perimeter — to balance the two requirements.

Specifying the ultra-slim variant is a deliberate decision against a particular elevation. The standard Maxlight sliding system is slim enough for most projects; the ultra-slim variant is for projects where the brief calls for as little aluminium as possible at the meeting rail, and the panel sizes work within the variant's engineering envelope.

When ultra-slim makes sense: a project asks for the meeting-rail aluminium to read as a hairline rather than a frame, the elevation is between three and five metres wide where the engineering envelope is comfortable, and the budget can absorb the uplift over the standard slim system. Where the brief is for the largest possible panel rather than the thinnest possible frame, the standard sliding range is the better answer; ultra-slim trades a small slice of structural envelope for the visible reduction at the interlock.

Detail considerations. The threshold detail integrates a primary aluminium track and a recessed cavity drained to outside per BS EN 12208 Class E1200; the head profile carries the carrier rail and a seal interface that pairs with the structural beam above the opening — coordinated with the project structural engineer at design stage. Junction detailing matters as much as the headline sightline: a 20 mm meeting rail in a poorly resolved threshold reads worse than a 28 mm meeting rail in a properly engineered one.

Regulatory context. The whole-window U-value is rated at 1.2 W/m²K against BS EN 14351-1 (Windows and doors product standard) and meets Approved Document L 2025 limiting U-values for replacement and new-build dwellings. Air permeability is Class 4 to BS EN 12207, water tightness Class E1200 to BS EN 12208, wind load Class C5 to BS EN 12210 — the suite of European product-standard certifications that an architect specifying for the UK market should expect. The rated figure is the BFRC whole-window value, not the centre-pane number.