The most common advice in this market is also the worst: buy the heaviest door. Adding steel to a leaf is cheap. Fitting hinges that will carry that weight for a decade, bolts that travel deep into the frame, and a frame properly anchored into masonry is the expensive part. There are specific things to inspect, and none of them is a scale.
Leaf stiffness beats leaf thickness
A leaf can be 70 mm or 90 mm deep; what matters is the structure inside it. Depth of the edge fold, the number of vertical and horizontal reinforcement profiles, and extra sheet backing behind the lock case. Test it by hand: close the door and press your palm 20 cm above the lock line. If the face gives, the cavity behind it is empty.
Locking: points and penetration
A three-point system ties the leaf to the frame at top, centre and bottom so no single line takes the whole load. Bolt penetration depth matters as much as point count, because shallow bolts release when a wedge is driven between leaf and frame. Also check for a steel escutcheon over the cylinder, a hardened plate in front of the lock case, fixed security pins on the hinge side, and a cylinder that does not protrude beyond the plate.
Hinges and adjustment
Bearing hinges adjustable in three axes are what keep a heavy leaf from dropping. Buildings settle and openings move; the difference between turning a hinge screw and dismounting the door is whether that adjustment exists. Above roughly 100 kg of leaf weight, expect three hinges rather than two.
Gasket line
Acoustic performance gets credited to the core, but most leakage happens around the leaf perimeter. Two rows of EPDM gasket cut corridor noise noticeably more than one. An automatic drop seal handles the bottom gap where no threshold is wanted. Check that the gasket runs unbroken around the corners; one gap defeats the whole line.
How the surface ages
Judge a finish by year five, not day one. In damp stairwells, membrane edges must stay down. In full sun, colour must hold. For exposed openings, high-pressure laminate surfaces such as our ultralam steel doors and composite panels outlast interior-grade coverings. Electrostatic powder coating carries no laminate layer at all, which is why it is standard on pressed sheet panel doors and fire doors.
Frame and installation
A good leaf in a badly fixed frame is a bad door. Frames are anchored into the structure and the void packed with mortar or proper backing rather than left to expanding foam alone. Frame depth has to match wall thickness or the architrave sits in air; adjustable 20-24 cm depth is standard on our lobby and villa frames for that reason.
Dimensions for export orders
State which figure you are quoting. Apartment doors: 90×200 cm clear frame opening, 108×210 cm at the architrave edge. Lobby and villa doors: 145×215 cm clear, 165×223 cm at the architrave. Fire doors: 90×200 cm clear, 104×208 cm at the architrave. Non-standard openings are made to order and priced on the measurements, so send us the wall opening in centimetres with the hand of the door. Orders are crated and loaded in Istanbul for road freight to Europe or containers to overseas markets.
