Hidden / flush-to-wall doors
Concealed hinges and a frame plastered into the wall. The stiff foam core keeps the large flat leaf true so it aligns with the wall surface.
Door materials guide
Aluminium Foam Panels for Door Leaves
An aluminium foam door uses a one-piece slab of cellular aluminium as the leaf core, framed with aluminium edge profiles and faced with a decorative skin. The result is a wood-free leaf that does not swell in humid rooms, has a non-combustible core and damps sound better than a hollow honeycomb door. Metline supplies the aluminium materials, foam core panels, frame and edge profiles and facing sheet, to door manufacturers and fit-out contractors worldwide.
- Core
- Closed-cell aluminium foam
- Leaf thickness
- Commonly 40 – 55 mm
- Frame
- 6063-T5/T6 extruded profiles
- Use
- Interior doors, hidden doors
What is an aluminium foam panel door?
Most interior door leaves are built from a timber or MDF frame around a core of paper honeycomb, particleboard, polyurethane or extruded polystyrene. An aluminium foam door replaces that core with a slab of closed-cell aluminium foam and replaces the timber stiles and rails with extruded aluminium edge profiles. Decorative skins, such as laminate, film, veneer or painted aluminium, are bonded to both faces.
Because every structural layer is metallic or inorganic, the leaf is dimensionally stable in bathrooms, kitchens, basements and coastal apartments, where wood-based doors tend to warp or swell at the edges. The foam core is also rigid enough to hold a flat face over a full-height leaf, which is why the construction suits flush "hidden" doors that must line up with the surrounding wall.
Metline does not make or install finished doors. We supply door makers with the aluminium that goes into them: foam core panels cut to leaf size, aluminium frame and edge profiles, and aluminium facing sheet or coil. This guide explains what those materials must achieve so that you can specify them.
Typical leaf build-up and the role of each layer
| Layer | Typical material | Function |
|---|---|---|
| Decorative face | HPL, PVC or PET film, wood veneer, painted or anodised aluminium sheet | Appearance, wear and cleaning resistance |
| Facing sheet (optional) | 0.3 – 1.0 mm aluminium sheet, e.g. 3003 or 5052 | Spreads point loads, protects the core, gives a flat bonding surface |
| Core | Closed-cell aluminium foam slab, usually 0.25 – 0.6 g/cm³ | Stiffness, flatness, sound damping, non-combustible core |
| Edge profile / frame | Extruded 6063-T5 or T6 profiles around the leaf perimeter | Edge protection, hinge and lock fixing, edge-banding seat |
| Door frame (jamb) | Extruded aluminium jamb profiles, commonly around 1.5 – 2 mm wall | Carries the leaf, holds seals and strike plates |
Leaf thickness for interior doors is commonly between about 40 and 55 mm, with 43 mm and 53 mm builds widely used for slim-frame and concealed-frame doors respectively. The core thickness is the leaf thickness minus the two faces. Hinges and locks should be fixed into the aluminium edge profile or into solid aluminium or hardwood blocks set into the core; screws in bare foam do not hold reliably.
Door styles that use aluminium foam cores
Slim-frame doors
Narrow aluminium sight-lines around a flat leaf. Frame profiles carry the visual design; the core provides flatness.
Flat panel doors
Plain flush leaves with laminate, film or veneer faces for apartments, hotels and offices.
Grooved and grille doors
Decorative grooves or applied aluminium strips. Groove depth must stay within the face layers or be planned into the core thickness.
Glazed doors
Foam-core leaves combined with glass panels held in aluminium glazing beads.
Inward- and outward-opening frames
Frames can be designed flush to one side of the wall or the other; the profile set determines this.
Performance compared with conventional door cores
| Criterion | Aluminium foam core | Paper honeycomb | Particleboard / MDF | PU / XPS foam |
|---|---|---|---|---|
| Moisture stability | Very good; does not swell | Poor if faces are damaged | Swells at edges if wet | Good |
| Core combustibility | Non-combustible | Combustible | Combustible | Combustible |
| Sound damping | Good; porous metal damps knocks | Low; leaves sound hollow | Good (heavy) | Low to moderate |
| Weight | Light to medium | Very light | Heavy | Very light |
| Flatness of tall leaves | Very good | Fair | Good | Fair |
| Formaldehyde | None from the core | Depends on adhesive | Depends on resin | None |
| Recyclability | Metal fully recyclable | Limited | Limited | Limited |
A non-combustible core does not by itself make a fire door. Fire resistance is a property of the complete tested assembly, including leaf, frame, seals, glazing and hardware, rated under standards such as EN 1634-1, BS 476-22 or UL 10C. Aluminium melts at about 600 – 660 °C, so fire-rated designs need tested detailing.
Frame and edge profiles: what to specify
- Alloy and temper: 6063-T5 or T6 for a good anodised or powder-coated finish; 6060 is an equivalent European choice.
- Wall thickness: main walls around 1.5 – 2 mm are typical for interior jambs, with local thickening where hinges and strikes screw in.
- Tolerances: precision profiles to EN 12020-2 help leaves and frames align with small, even gaps.
- Finish: anodised, powder coated (Qualicoat or AAMA classes), wood-grain sublimation or film-wrapped; order frames and leaf trims in one batch for colour match.
- Seals and hardware grooves: design grooves for the chosen gasket, magnetic lock and concealed hinge system before die making.
- Thermal or acoustic inserts: where acoustic rating matters, frames can include gasket channels on both stops.
For custom profiles, see aluminium door profiles and the door profile systems page, which cover die design and finishes in detail.
Cutting, bonding and finishing foam door cores
Cutting
Foam slabs cut cleanly with carbide-tipped circular saws or band saws; CNC routers form hinge and lock pockets. Extract the fine chips.
Bonding
Two-component PU or epoxy adhesives, or hot-melt PUR, bond faces to foam. Clean and dry surfaces; the open cut cells give a good mechanical key.
Edge sealing
PUR edge banding or aluminium edge profiles close the leaf so cut cells are not exposed.
Hardware fixing
Use through-bolts, rivet nuts in the edge profile, or solid inserts in the core for hinges, locks and closers.
Pressing
Cold or hot presses with even pressure keep the leaf flat; avoid point pressure that could dent the foam.
Quality checks
Check leaf flatness, diagonal squareness, bond strength by peel test and face appearance before packing.
Where aluminium foam doors are specified
- Residential: bathrooms, kitchens and humid climates where wood-core doors warp.
- Hotels and serviced apartments: durable, quiet leaves that keep their alignment through heavy use.
- Offices: flush meeting-room and partition doors matched to aluminium partition systems.
- Healthcare and laboratories: cleanable faces and wood-free cores.
- Yachts, rail and modular buildings: light, stable doors with a non-combustible core.
References and standards
- ISO 13314 – Mechanical testing of metals: compression test for porous and cellular metals
- M.F. Ashby, A.G. Evans, N.A. Fleck, L.J. Gibson, J.W. Hutchinson, H.N.G. Wadley – Metal Foams: A Design Guide (Butterworth-Heinemann)
- J. Banhart – Manufacture, characterisation and application of cellular metals and metal foams, Progress in Materials Science 46 (2001)
- EN 1634-1 – Fire resistance and smoke control tests for door and shutter assemblies
- EN 13501-1 – Fire classification of construction products and building elements
Aluminium foam door panels: frequently asked questions
Is an aluminium foam door a fire door?
Not automatically. The foam core is non-combustible, but a fire rating applies only to a door assembly tested to a standard such as EN 1634-1 or UL 10C, including frame, seals and hardware.
How thick is an aluminium foam door leaf?
Interior leaves are commonly 40 – 55 mm thick. 43 mm suits slim-frame doors, and around 53 mm is used for larger or concealed-frame doors.
Do aluminium foam doors warp in bathrooms?
They are far more stable than wood-based doors because the core and frame do not absorb water. Faces and edge banding should still be suited to humid rooms.
How are hinges fixed to an aluminium foam core?
Into the aluminium edge profile, through-bolted, or into solid inserts set into the core. Screws driven only into foam do not hold reliably.
Does Metline supply complete doors?
No. Metline supplies the aluminium materials: foam core panels, extruded frame and edge profiles and facing sheet, to door manufacturers and fit-out contractors.
Is aluminum foam heavier than a honeycomb door core?
Yes, a foam core is heavier than paper or aluminium honeycomb, but much lighter than particleboard, and it gives better sound damping and flatness.
Building aluminium foam doors?
Send your leaf sizes, core build and profile drawings. We will quote foam panels, profiles and sheet for your production.
