Domakihub How to Fit an Internal Door Lining — and Get It Plumb
A clear, practical guide to measuring, cutting, and installing a door lining in any home, rental, or hotel room.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
A door lining (also called a door frame or door casing) is the timber box that lines the rough opening in a wall and supports the door itself — get it wrong and the door will never hang or close properly. The video above from Tommy's Trade Secrets walks through the installation process on camera, while this guide breaks every stage into ordered steps with measurements and tips relevant to homes, holiday rentals, and hospitality properties across Greece. Whether you are replacing a damaged lining after replastering or fitting one to a new opening, this is what you need to know before picking up a saw.
What Is a Door Lining and When Do You Need a New One?
A door lining consists of three timber boards — two vertical legs (jambs) and a horizontal head — assembled into a U-shape that fills the gap between the rough masonry or stud opening and the door itself. The architrave is then nailed over the lining to cover the joint with the wall finish. Linings are sold as pre-machined kits (with a groove already routed for the door stop) or can be cut from 32 mm timber to suit non-standard walls.
You need a new lining when the existing one is rotten, split, or so badly damaged by replastering that it has moved out of plumb. In Greek properties — especially older stone-built or brick construction with thick walls — wall depths can vary significantly from one opening to the next, so always measure before ordering material.
When to Call a Licensed Professional
Fitting a door lining in a standard partition or block wall is a task a competent DIYer or carpenter can handle without a permit. However, if the opening sits in a load-bearing or structural wall — identifiable by its thickness, position, or an engineer's drawing — then creating or enlarging it requires a structural engineer's sign-off and, in Greece, a building permit (oikodomiki adeia) under Law 4495/2017. Do not widen or raise an existing structural opening without professional approval.
Damp-proof course issues, fire-door assemblies (required in multi-unit buildings and hotels under Greek fire-safety regulations), and heritage properties under preservation orders all require licensed tradespeople. For everything else, the steps below apply.
How to Fit an Internal Door Lining: 5 Steps
- 1
Measure the Opening and Prepare Your Timber
Measure the height and width of the rough opening at three points each — top, middle, and bottom for width; left, centre, and right for height. Use the smallest reading in each direction as your working dimension. Subtract 10 mm from the width to leave clearance for adjustment, and allow the head to sit 3–5 mm above finished floor level. Measure the wall depth (the distance from face to face of the plaster or board) and select lining boards of matching width — typically 95 mm, 108 mm, or a custom rip. Mark and cut the two leg pieces to length at 90°, then cut the head piece to the exact internal width of the finished opening.
- 2
Assemble the Lining Frame
Lay the three pieces on a flat surface. The head board sits on top of the two legs — butt-jointed or, on a pre-machined kit, slotted together. Drill two clearance holes through the end of the head and into the top of each leg, apply a bead of PVA wood glue, and drive 65 mm screws to pull the joints tight. Check the internal width at the top, middle, and bottom with a tape; it must equal the door width plus 3 mm clearance on each side. Check the diagonals — if they match, the frame is square. Cut a temporary timber spreader to lock the width and tack it across the bottom of the legs.
- 3
Offer Up and Plumb the Frame
Lift the assembled frame into the opening. Wedge the legs so the head is level — check with a spirit level both across the head and down each leg. A plumb leg is more important than a level head if the floor is uneven; prioritise the hinge side first. Once satisfied, push folded timber wedges (offcuts work well) behind each leg at the top, middle, and bottom to hold position without nailing. Re-check plumb after inserting wedges, as they often shift the frame slightly.
- 4
Fix the Lining in Place
With the frame plumb and wedged, drill clearance holes through the leg at each wedge position and into the masonry or stud behind. In concrete or block walls, use a masonry bit and plug with 60 mm No. 10 frame fixings or proprietary frame anchors. In timber stud walls, 65 mm oval nails or screws into the studs are sufficient. Fix the hinge leg first, then the latch leg, checking plumb after each fixing. Remove the temporary spreader once both legs are secured. Fill any gap between the lining and the wall with expanding foam (low-expansion formula inside the building) and allow to cure for the time stated on the tin before trimming flush.
- 5
Fit the Door Stop and Check the Door Swing
If your lining does not have a pre-routed stop groove, nail a 12 mm x 38 mm timber door stop to each leg and the head. The stop sits 3 mm back from the face of the lining on the hinge side to allow the door to close cleanly, and flush with that same face on the strike side. Hang the door temporarily (without ironmongery) to check it swings freely without catching the frame and that the gap around three edges is even at approximately 2–3 mm. Once confirmed, remove the door, paint or seal the lining, then rehang and fix the architrave to cover the joint with the wall finish.
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FAQ
- What width of lining board do I need for a standard Greek brick or block wall?
- Most internal block walls in Greek construction are 10–12 cm wide before plastering on both sides. With a 1.5 cm plaster coat on each face the finished wall depth typically runs 130–150 mm. Standard lining kits come in 95 mm and 108 mm widths — for thicker walls, buy 32 mm timber and rip it to the exact finished wall depth on a table saw, or ask your timber supplier to machine it to width.
- Can I fit a door lining myself or do I need a licensed carpenter in Greece?
- A plain interior door lining in a non-structural partition wall does not require a licensed tradesperson or a permit under Greek law. However, if the opening is in a load-bearing wall, involves a fire-rated assembly (common in apartments and hotels under Greek fire-safety code), or the building is subject to a preservation order, a licensed engineer or certified carpenter must be involved. For holiday rental properties in Greece, fire-door requirements in common areas are strictly enforced — check with your local fire authority before assuming a standard lining is adequate.
- How do I stop the door lining moving after installation in a damp or newly plastered room?
- Allow new plaster to dry fully — at least four weeks in a ventilated room — before fitting timber linings. Fresh plaster transfers moisture into the wood and causes warping. If the room is exposed to humidity (bathrooms, ground-floor rooms in coastal properties), choose moisture-resistant MDF linings rather than softwood, prime all faces including the back before installation, and use low-expansion foam with a vapour barrier behind the lining rather than packing with wood. Fix firmly at close centres — no more than 400 mm between fixings — to resist seasonal movement.