How to Install a Concealed Door: A Step-by-Step Guide

A concealed door is one of the few doors where the installation is the finish. There’s no architrave to hide a wobbly frame or a rough plaster edge, so whatever you build is exactly what you’ll see. Get it right and the door reads as a clean line in the wall. Get it wrong and you’ll be looking at uneven gaps and hairline cracks for years.

This guide explains how a concealed door is installed in a plasterboard stud wall and in a masonry wall, in the order the work actually happens. Every system is slightly different, so treat this as an overview and always follow the instructions for the frame you’re fitting.

Before you start: the key thing to understand

The most important point is timing. On most concealed systems, the frame is built into the wall before the wall is finished.

Italian door maker FIP Porte puts it simply in its installation guide: the aluminium frame is fixed into the wall and disappears under the finish, so the door is installed while the wall is being built, not afterwards. Concealed frame manufacturer Dorsis gives the same order of work: fix the frame after the rough opening is ready but before final plastering, screeding, tiling and floor finishes.

So a concealed door is really a job for the build or renovation stage, with the frame on site before the plasterer. If your walls are already finished, it’s still possible, but expect to cut back and make good the plaster around the opening.

What you’ll need to decide first

Settle these points before anything is fixed in place.

Push or pull

A concealed hinged door is flush on one face of the wall only. The face it opens away from is usually the flush side. Manufacturers sell push and pull versions, and some sets are reversible. Our Concealed Omega Primed Door Set and Frameless Hidden Door, for example, can be installed left or right, push or pull. Our guide to concealed door frame details explains how to choose.

The finished wall thickness

The frame has to suit the finished wall, including boards and plaster on both sides, not just the studs. Minimums vary between systems, so check the data sheet for yours.

The finished floor level

Concealed doors are set from the finished floor, not the subfloor. If the floor isn’t down yet, you need to know its final height. FIP Porte’s instructions, for instance, set the door 6mm off the floor using a wedge during installation. Other systems give their own figure.

The opening size

Each frame needs an opening prepared to a specific size. Use the manufacturer’s table. If you’re having a door made to your opening, our guide on how to measure for a concealed door walks through it.

How to install a concealed door in a stud wall

This is the most common situation in UK renovations and extensions. The steps below follow the general sequence in FIP Porte’s plasterboard instructions and Invisible Door’s guide for hinged flush doors.

1. Build the opening

Build the studwork around the opening to the size the frame needs, with the head and both sides straight and square. A frame can only be as good as the opening it goes into, and there’s no trim to hide errors later.

2. Set the frame in the opening

Place the frame in the opening, with the door in it if the system is designed to be fitted that way. Wedge the door to the correct height above the finished floor.

3. Plumb, level and square it

This is the step that makes or breaks the job. Check both jambs are plumb and the head is level, and that the frame isn’t twisted. Invisible Door’s instructions say to check the frame with a plumb line before securing it. Open and close the door as you go to make sure it swings freely and the gaps look even.

4. Fix the frame to the studs

Screw the frame to the structure using the brackets or fixing points provided. FIP Porte uses self-drilling screws into the metal stud structure. Follow your system’s fixing positions, and pay particular attention to the hinge side, which takes the weight of the door. Australian frame maker EzyJamb, for example, specifies extra screws both above and below each hinge position.

5. Board up to the frame

Fix the plasterboard so it meets the frame exactly as the instructions show. On some systems, the boards are screwed directly onto the edge of the frame. On others, an aluminium profile overlaps the board. Don’t improvise this detail, because it’s what controls cracking.

6. Tape, fill and plaster to the frame line

Reinforce the joint between frame and board using the tape or mesh specified. Invisible Door says to carefully tape and reinforce the wall joints between the plasterboard and the aluminium frame. Then fill and plaster, using the frame edge as your finished line. FIP Porte describes the frame as setting the line that the boards and skim coat follow.

Brief your plasterer before they start. Dorsis stresses that the plasterer needs to know the final surface thickness, the front plane and how the transition between frame and wall will be finished.

How to install a concealed door in a masonry wall

In block or brick walls, the frame is anchored into the wall and then skimmed in. FIP Porte’s masonry sequence looks like this:

1. Position the frame with its stiffening spacers in place, and plumb it.
2. Set the door at the right height off the floor using a wedge.
3. Fix the anchors into the wall, testing that the door works as you go.
4. Apply the mesh supplied so it overlaps between the frame and the masonry. FIP Porte notes this is the stage to make small adjustments.
5. Fill between frame and masonry.
6. Leave the spacers in until the cement has fully dried. FIP Porte specifies 12 hours for its system.
7. Skim the walls following the plaster line set by the frame.

If you’re working with an existing masonry opening, check it’s big enough and square before ordering. Cutting or widening an opening in a loadbearing wall is structural work and may need a lintel and Building Regulations approval, so get professional advice first.

Hanging the door and adjusting the hinges

On many systems, the door is hung or re-hung once wet trades have finished and the plaster has dried. If the door comes out during plastering, keep plaster and dust out of the hinge pockets. Some manufacturers supply or sell protection plugs for exactly this.

Concealed hinges are usually adjustable, often with an Allen key, so you can fine-tune the gaps once the door is hung. Invisible Door recommends shimming under the bottom of the door while you adjust the hinges, so they aren’t carrying the door’s weight. Remove the shims afterwards. Aim for consistent gaps along the top and both sides, and a door that closes onto the latch without rubbing.

Our guide to concealed door hinges covers the main hinge types and what they can adjust.

Finishing: painting and hardware

Concealed doors are usually painted to match the wall. FIP Porte recommends painting both sides of the door at the same time. Paint the door, frame edge and wall together for a seamless look. For more detail, see our guide on how to paint a concealed door.

Then fit the latch and any handle. Magnetic latches and flush or push-to-open options keep the look minimal. Browse our concealed door hinges, latches and handles.

Common mistakes to avoid

• Fitting the frame after plastering on a system designed to be plastered in.
• Setting the height from the subfloor instead of the finished floor.
• Skipping the plumb and level checks or relying on a short spirit level over a tall frame.
• Too few fixings on the hinge side, which can lead to a dropped door.
• Improvising the plaster junction instead of using the specified tape, mesh and filler.
• Hanging the door too early, before the plaster has dried.

Frequently asked questions

Can I install a concealed door in an existing wall?

Yes, but most concealed frames are designed to be fitted before the wall is finished, so expect to cut back the plaster around the opening, fit the frame and then make good. Check the opening is the right size and square before ordering.

Is a concealed door a DIY job?

A confident DIYer with plastering skills can fit some systems, but the tolerances are tight and there’s no architrave to hide mistakes. Many people use a carpenter for the frame and an experienced plasterer for the finish.

When should the door be hung?

Follow your system’s instructions. On many systems, the door is hung or re-hung once the plaster has dried, then the hinges are adjusted.

Why does plaster crack around concealed door frames?

Usually because the frame wasn’t fixed rigidly enough, or the junction between frame and wall wasn’t reinforced as the manufacturer specifies. A door opening and closing thousands of times puts movement into that joint.

Can a concealed door be a fire door?

Yes, if you use a tested and certified FD30 concealed system, installed exactly as specified. See our guide to FD30 concealed doors.

Ready to choose your concealed door?

Browse our concealed doors, or ask about a door made to your opening through our made-to-measure service. If you’d like help choosing a frame for your wall, contact our team.