The perimeter reveal on a filomuro door: how wide is normal?
The thin line running around a flush door is the only thing that gives it away. When it stays constant on all four sides, the eye reads it as a design detail. When it opens up in one corner and closes in the other, that same line becomes the first thing anyone notices walking into the room. This article covers what reveal width is normal, why it goes uneven, and what can still be corrected after installation.
What the perimeter reveal is and why it cannot be eliminated
The reveal is the clearance between the door edge and the concealed frame, on all four sides. It is not a tolerated imperfection but a design dimension. A door needs clearance to swing without binding, and its materials change size with temperature and humidity. A zero reveal would mean a jammed door at the first change of season.
On conventional doors the reveal is hidden by architrave. Nobody looks at it, because the visible frame absorbs every deviation in the opening. A filomuro door has no architrave, so the reveal is fully exposed. That moves tolerance from the invisible into the permanently visible, and explains why installing an invisible door demands a precision that common installation mistakes expose faster than anything else.
How wide the reveal should be
The usual figure on filomuro doors is around 3 mm on each vertical side and along the top. It is enough for the door to swing freely and absorb material movement, yet small enough that the line stays discreet at normal viewing distance.
Consistency matters more than the number itself. A uniform 3.5 mm reveal all the way round looks right. A reveal drifting between 2 mm and 4 mm on the same side looks wrong, even if the average is exactly 3 mm. The eye is very good at detecting two parallel lines converging, especially vertically and especially under grazing light.
- Below 2 mm: risk of binding as temperature and humidity shift. The door starts catching the frame in summer, or once the heating comes on.
- 2.5–3.5 mm: the normal working range. Silent operation, and the line reads as intentional.
- Above 4.5 mm: the reveal becomes a visual element in its own right. Continuity with the wall is lost and the door reads as an applied panel.
Direct comparison: reveal behaviour by frame material
Installation sets the initial reveal width. How much of it survives the years is set by the material of the door's perimeter frame. A material that absorbs moisture changes size seasonally, and the reveal tightens and widens along with it.
| Frame material | Nominal reveal | Seasonal variation | Binding risk | Long-term stability |
|---|---|---|---|---|
| HDF | 3 mm | ±1–1.5 mm | High | Visibly degrades within 2–3 years |
| Solid timber | 3 mm | ±0.8–1 mm | Medium | Depends on species and indoor humidity |
| Extruded aluminium | 3 mm | under 0.5 mm | Minimal | Constant for the full service life |
The difference is not workmanship, it is physics. Aluminium absorbs no water at all, and its thermal expansion inside a heated home stays under half a millimetre across a door's height. HDF changes dimension with airborne humidity, and that movement accumulates in the reveal. This is why an extruded aluminium frame remains the core technical argument behind the Filomuro Minimal and Signature doors.
Why the reveal goes uneven
In almost every case the cause predates the door. The concealed frame copies the geometry of the opening it sits in, and if the opening is not true, the door cannot fix it.
- Frame out of plumb. A 2 mm deviation over a 2.1 m height produces a reveal that closes progressively towards the top. This is the most common cause by far.
- Opening not square. Unequal diagonals translate directly into a wedge-shaped reveal.
- Substrate that moves. On drywall without adequate noggins, the structure gives a few millimetres under the door's weight and the reveal shifts weeks after installation.
- Hinges never adjusted. The door hangs correctly but final fine-tuning was skipped, leaving the leaf slightly offset in the frame.
- Plaster run over the frame. The finish coat narrows the opening locally and pinches the reveal along a stretch.
What can be corrected after installation, and what cannot
The good news is that most reveal problems are solved without anyone pulling the frame out of the wall. The concealed hinges used on filomuro doors adjust on three axes, which covers the bulk of everyday deviations.
- Lateral adjustment: shifts the leaf left and right, equalising the reveal between the hinge side and the lock side.
- Height adjustment: raises or lowers the door, correcting the top reveal and the floor clearance.
- Depth adjustment: brings the leaf flush with the wall plane, removing any proud or recessed look.
What hinges cannot fix is a frame set crooked. Once the deviation exceeds the adjustment travel, the only real remedy is removing and repositioning the frame. Checking plumb during installation with the door actually hung, rather than on the empty frame alone, saves an entire return visit later.
The floor gap, a separate case
The gap between door and floor follows different logic. It is not about aesthetics but about room ventilation and the final floor build-up. The usual value is 8–10 mm above finished floor level, wider than the perimeter reveal precisely to let air move towards rooms without vents.
Trouble starts when the door is ordered before the final floor level is known. Engineered flooring with acoustic underlay fitted afterwards can raise the level by 12–15 mm and turn a correctly calculated gap into a binding door. On floor-to-ceiling doors, where the leaf is taller and heavier, the margin for error is smaller still.
How wide should the reveal be on a filomuro door?
Around 3 mm on the vertical sides and along the top, plus 8–10 mm above finished floor level. More important than the exact figure is that the reveal stays constant all the way round: a uniform 3.5 mm looks right, while drifting from 2 to 4 mm on the same side is immediately visible.
Why is my reveal wider on one side than the other?
In the vast majority of cases the frame is not perfectly plumb, or the opening's diagonals are unequal. The door simply copies the frame's geometry. If the difference is a millimetre or two, hinge adjustment compensates for it. Beyond that, the frame has to be repositioned.
Can the reveal be adjusted after installation?
Yes. Concealed hinges adjust on three axes: lateral, height and depth. A fitter can equalise the reveal in a few minutes without removing the frame or touching the wall finish. The adjustment is made with the door hung, checking the reveal over the full height rather than only at handle level.
Does the reveal change over time?
That depends entirely on the frame material. With an extruded aluminium frame the reveal stays practically identical year after year, because aluminium absorbs no moisture. HDF frames tighten in summer and widen in winter, and after two or three years the distortion becomes permanent. Checking the adjustment once a year is enough to keep the line constant.
The perimeter reveal is the practical proof of an invisible door's quality: it shows both how precise the installation was and how stable the door's material is. To see the difference on a real leaf, Filomuro Minimal and Signature doors are on display in the showroom at Bulevardul Dacia 153-155, Bucharest, Monday to Friday from 10:00 to 18:00. Sizes and configuration can be calculated directly in the online configurator.
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