Door frame and door lining are two terms the UK trade uses almost interchangeably, and that casual overlap causes real ordering mistakes. They are not quite the same thing, they suit different openings, and choosing the wrong one means either a door that will not close or a job that needs redoing.
This guide explains the difference in plain terms, shows what each costs from our own live range, and walks through how to choose, measure and order. Doors2Floors has supplied doors and flooring to homes and businesses across the UK, and our internal frames and linings collection currently holds over 30 lines.
The Short Answer
A lining is a plain timber casing that lines a structural opening, with a separate planted door stop nailed on afterwards to give the door something to close against. A frame is a casing with the stop already machined into it as a rebate, so the door closes into a solid moulded section rather than against a strip pinned on later.
The practical difference
Linings are the standard for internal doors in UK homes. Frames are the standard for external doors and for internal doors where a rebated section is wanted for strength, sealing or fire performance.
Why the words get mixed up
Manufacturers and merchants often sell a product called a lining frame, which is a lining supplied with a loose stop in the same pack. That single product name contains both words, which is where most of the confusion begins.
What matters when ordering
Not the word on the label, but three measurements: the door size it suits, the depth of your wall, and whether the stop is loose or rebated.
What a Door Lining Actually Is
The basic construction
Two vertical jambs and a head, cut and jointed to form a three sided casing that lines the structural opening. The timber is plain and rectangular in section.
The loose stop
A separate thin strip pinned to the inside faces of the lining once the door is hung. Because it goes on last, it can be positioned to suit the door as it actually hangs rather than as it should theoretically hang.
Why a loose stop is genuinely useful
Older UK openings are rarely perfectly square. A loose stop lets the fitter set the closing line to the door in front of them. A rebated frame gives no such flexibility.
Where linings are used
Almost every internal door in a typical UK house. They are the default and there is nothing second rate about them.
What linings do not do
They provide no weather seal and are not intended for external openings.
Lining set prices
Our white primed softwood door lining sets with loose stop start at £29.25. Oak options sit considerably higher, with a blonde oak curved lining frame at £230.18.
What a Door Frame Actually Is
The basic construction
A jamb and head assembly with the door stop machined into the timber as a rebate rather than pinned on. The section is thicker and more substantial than a plain lining.
Why the rebate matters
A rebated section is stronger, gives a cleaner line, and provides a consistent seat for seals. That matters on external doors and on assemblies where sealing is part of the specification.
Where frames are used
External doors, and internal doors where a rebated section is specified. Our LPD External Hardwood Door Frame and Cill is currently £109.15 and includes the weather cill that no internal lining has.
Frames with cills
An external frame usually includes or accepts a cill, which throws water clear of the threshold. This is the single biggest structural difference from an internal lining.
Frame kits for special door types
Folding doors need a frame kit that carries the track. Our Deanta bifold frame kits start at £345.50 in white primed, £375.75 in unfinished oak, £391.50 in fully finished oak and £406.25 in fully finished walnut, reaching £624 in the widest configurations. Our bifold door costs guide covers the arrangements.
Complete door kits
Our door kits and fitting hardware section holds over 15 lines including complete single door kits with handle and doorjamb from £275.75 and double door kits from £554.25.
Choosing Between a Lining and a Frame
Is the opening internal or external?
External openings need a frame with a cill. This is not a preference, it is what keeps water out.
Is the opening square?
The less square the opening, the more you will appreciate a loose stop.
Is the door heavy?
Heavier leaves benefit from the more substantial section of a frame, and from hinges fixed into something solid. Our over 290 internal oak doors from £87.75 and over 280 glazed doors from £107.25 are both at the heavier end.
Is the door fire rated?
Fire door assemblies are certified as a whole, and the frame or lining is part of that assembly. What you may use is set by the certification, not by preference.
Is sealing important?
A rebated section gives a more consistent seat for seals, which matters where sound, smoke or draughts are a concern. Our draughty doors guide covers the practical side.
What is already there?
If the existing casing is sound, square and the right depth, reuse it. That single decision saves more money than any other on a door project.
What is your budget?
Lining sets from £29.25 against complete kits from £275.75 is a wide gap, and the difference is mostly convenience and completeness rather than quality.
Who is fitting it?
A confident fitter will happily work with a lining and a loose stop. A complete kit removes specification risk if you are less certain.
Wall Thickness and Lining Depth
This is where most ordering errors actually happen, and it has nothing to do with the frame versus lining question.
Measure the wall, not the door
Lining depth must match the finished wall thickness, including plaster or plasterboard on both faces.
Common UK wall build ups
Stud walls, blockwork with plaster, and older lath and plaster all give different finished thicknesses. Measure yours rather than assuming a standard.
Too shallow
The lining sits proud on one side and the architrave will not sit flat. It looks wrong and it is difficult to disguise.
Too deep
The lining projects and has to be planed back on site, which wastes time and rarely looks as clean.
Where to measure
At several points around the opening. Walls are rarely a consistent thickness, particularly in older properties.
Allow for the finish
Measure the finished surface, not the bare block or stud.
Check against the product
Our lining sets are supplied in depths to suit common wall build ups. Confirm the depth before ordering rather than after delivery.
Measuring for a Lining or Frame
The structural opening
Measure the width at three heights and the height at three widths, then work to the smallest figures.
Check both diagonals
Equal diagonals mean a square opening. Unequal diagonals tell you how much work is coming.
Check plumb and level
A long spirit level down both reveals and across the head. Note anything out.
Work back to the door size
The opening has to accommodate the lining plus the door plus the fitting gaps. Our internal door sizes guide lists the standard UK sizes.
Follow a proper method
Our door measuring guide walks through the full sequence including lining depth and floor covering allowance.
Allow for the floor
New flooring raises the finished floor level and reduces the gap under the door. Sequence the floor first where you can. Our flooring range of 12 Karndean lines from £14.00 and our notes on flooring mistakes cover it.
Record everything per opening
One line per door. That schedule is what you order from and what you give a fitter to quote against.
Fitting a Lining or Frame
Assemble before installing
Most lining sets arrive as loose components. Assemble them square on a flat surface before offering them into the opening.
Fix plumb, not to the wall
The wall is the wrong reference. Fix the lining plumb and square, then pack the gaps behind it.
Pack behind every fixing
Unpacked fixings pull the jamb into a curve as they tighten. That curve is what makes a door bind halfway through its swing.
Check the diagonals again
After fixing and before hanging. It is much easier to correct now.
Hang the door before fitting the stop
This is the whole advantage of a loose stop. Hang the leaf, let it find its natural closed position, then pin the stop to it.
Leave a consistent gap
Even gaps down both stiles and across the head. Our guide on planing a door covers adjusting the leaf if needed.
Fit the hinges into solid timber
At least one long screw per hinge into the structure behind the lining on heavier doors. Our guide on where to fit door hinges covers positions, and our over 350 hinge lines start at £2.37 for ball bearing patterns.
Then the architrave
Architrave covers the joint between the casing and the plaster. Our architraves guide covers profiles and mitres.
Then decorate
Caulk the architrave joint, fill the pins, and paint. Our painting guide covers the method.
Materials and Finishes for Casings
White primed softwood
The default and the cheapest. It arrives with a base coat and you apply the topcoats, which lets you match the casing to the door and the skirting exactly.
Unfinished softwood
Bare timber that you prime and paint yourself. Cheapest in material terms and the most work.
Oak
Chosen where the casing is meant to be seen as timber rather than painted. It costs considerably more and it needs sealing. Our oak care guide covers maintenance and our over 290 oak doors from £87.75 are the usual partner.
Walnut and darker timbers
Available in kit form, notably in the bifold frame kits at £406.25. Our oak versus walnut guide covers the difference, and we list over 30 walnut doors from £167.45.
Matching casing to door finish
A painted casing with an oak door is a deliberate and very common choice. An oak casing with a painted door is much less common and usually looks accidental.
Matching casing to skirting
Architrave and skirting meet at floor level, so their profiles and finishes should agree. Our architraves guide covers the junction.
Sealing before fitting
Prime or seal the back of a casing before it goes into a masonry opening. It will never be accessible again.
A note on older homes
UK homes decorated before 1992 may carry lead paint on existing casings and architraves. Do not dry sand and do not burn off. Take advice on safe removal first.
Room by Room Casing Decisions
Front entrance
Frame with cill, fixed properly into masonry, with the security of the whole assembly in mind.
Hallway and landing
Highest traffic and most visible architrave in the house. Worth getting the profile right.
Living room
Often a wider opening or a pair. Consider whether a divider or french pair suits better than a single leaf.
Kitchen
Steam and cleaning. A wipeable painted finish beats bare timber here.
Bathroom
Humidity is hard on casings. Seal all faces including the back, and expect to redecorate sooner.
Bedrooms
Standard linings with loose stops. Nothing exotic needed.
Home office
If sound matters, a rebated section with seals does more than a heavier leaf alone.
Utility and understairs
Often non standard openings. Measure these first, not last.
Garage to house
Frequently a fire separation opening. Confirm what the assembly must be with your local building control body before ordering anything.
Loft and attic
Compact openings where our 2 ladder door lines and simple linings usually suffice.
Conservatory
Big temperature swings, so seal thoroughly and expect more movement. Our conservatory flooring notes cover the same issue underfoot.
Rental properties
Durability over appearance, and check fire separation obligations for the property type with a competent professional.
Consents and When to Ask
Structural openings
Forming or widening an opening is structural work and needs structural advice before anything is cut.
Listed buildings and conservation areas
Listed building consent, conservation area rules, Article 4 directions, covenants and leasehold terms can all restrict changes to internal joinery. Ask your local planning authority, freeholder or management company first.
Fire separation
Confirm requirements with your local building control body or a competent fire risk assessor rather than any published summary.
Damp and rot
Rot at the foot of a jamb usually means a damp problem behind it. That is a job for a qualified surveyor or damp specialist before a new casing goes in.
Ventilation
Never block ventilation serving a gas or solid fuel appliance and never block underfloor airbricks.
Electrical
Moving a switch to clear a new architrave is work for a qualified electrician.
Fire Doors: Frames and Linings Are Part of the Assembly
The assembly is certified, not the leaf
A fire door performs as a complete assembly. The leaf, the frame or lining, the hinges, the intumescent and smoke seals, the latch, the closer and any glazing were all tested together.
You cannot mix and match
Fitting a certified leaf into an ordinary lining does not give you a certified assembly. The casing is not an accessory.
Seals
Intumescent and smoke seals sit in a groove in either the leaf or the casing depending on the specification. Never paint or fill that groove.
What we will not tell you
We will not tell you what your specific building requires or that any particular product satisfies any particular regulation. We are a supplier, not your fire risk assessor.
Who to ask
Your local building control body, a competent fire risk assessor or a suitably qualified professional, working from the door manufacturer instructions.
Our fire door range
We list over 240 fire doors from £87.39, including over 150 FD30, 8 FD60 and over 50 glazed fire door lines. Our guides on what fire doors are and where they go, fire door materials and stopping a fire door slamming are background rather than compliance advice.
Never do these things
Never wedge or prop a fire door open. Never block the threshold gap. Never remove the closer. Never plane the leaf beyond the certified allowance, including to clear a new floor.
Casings for Other Door Types
Bifold doors
Need a frame kit that carries the track. Our 15 bi fold door lines from £131.35 pair with kits from £345.50, and our explainer on how bifolds work covers the mechanism.
Pocket doors
The casing goes inside the wall as a cassette. Our 4 pocket door systems start at £298.99, with a fire rated single system at £849.99.
Sliding doors
Surface mounted track rather than a rebated casing. We list 16 sliding door kit systems.
French pairs
Rebated pairs meet each other rather than a stop, so the casing detail differs. Our 3 french door pairs start at £407.44 and our french doors guide covers the opening.
Room dividers
Large multi panel assemblies that need a properly prepared structural opening. Ours run from £498.06 to £1,392.15 across 17 room divider configurations.
Stable doors
Two independently hung halves in one casing. Our stable doors guide covers the detail.
External doors
Frame with cill, every time. Our over 90 external doors from £86.79, 18 composite sets from £725.00 and over 30 glazed external doors from £274.81 all need one. Our front door costs guide covers it.
Common Mistakes
Ordering the wrong depth
The single most common error. Measure the finished wall thickness at several points.
Fixing to the wall instead of plumb
The wall is not the reference. Plumb and square are.
Not packing behind fixings
Causes a bowed jamb and a binding door.
Pinning the stop before hanging the door
Throws away the main advantage of a lining.
Replacing a sound casing out of habit
A straight, firmly fixed lining does not need replacing because the door is new.
Using an internal lining externally
No cill, no weather protection, and a problem within a season.
Assuming a certified leaf makes a certified assembly
It does not. The casing is part of the certification.
Forgetting the architrave
New casing almost always means new architrave and some making good.
Buying in three separate orders
Door, casing and ironmongery in one delivery. Our over 700 internal doors from £30.84, over 280 handle packs from £8.99 and lining sets from £29.25 can all travel together. Our internal door fitting costs guide covers the whole budget.
Frequently Asked Questions
What is the difference between a door frame and a door lining?
A frame has the door stop machined into it as a rebate. A lining is plain, with a separate stop pinned on after the door is hung.
Which do I need for an internal door?
A lining in almost every case. It is the UK standard for internal openings.
Which do I need for an external door?
A frame with a cill. An internal lining will not keep weather out.
What is a lining set?
The jambs, head and loose stop supplied together as one product. Ours start at £29.25 in white primed softwood.
What depth lining do I need?
One that matches your finished wall thickness including the plaster on both faces. Measure at several points.
Can I reuse my existing lining?
Yes, if it is straight, sound, firmly fixed and the right depth for your wall and door.
Do I fit the stop before or after the door?
After. Hang the door, let it find its closed position, then pin the stop to it.
Why does my door bind halfway through its swing?
Usually a bowed jamb caused by fixings tightened without packing behind them.
What is a door kit?
A complete package of casing, doorjamb and handle in one order. Ours start at £275.75 for a single door.
Do fire doors need special linings?
They need whatever the certified assembly specifies. Confirm with your local building control body or a competent fire risk assessor.
What about bifold and pocket doors?
Both need their own purpose made kits rather than a conventional lining.
Is oak available?
Yes. Oak lining frames sit considerably above softwood, with a blonde oak curved lining frame at £230.18.
Do I need architrave?
Almost always, to cover the joint between the casing and the plaster.
How many linings will I need?
One per opening where the existing casing is being replaced. Walk the house and mark each one keep or replace.
Can I fit a lining myself?
Yes, if the opening is reasonably square and you are patient with packing and checking.
What if my opening is badly out of square?
A lining with a loose stop is your friend, because you can set the closing line to the door as it actually hangs.
Buying Linings and Frames From Doors2Floors
We have supplied doors and flooring to homes and businesses across the UK. Our internal frames and linings collection holds over 30 lines, with white primed softwood lining sets from £29.25 through to oak curved lining frames at £230.18, plus bifold frame kits from £345.50 and complete door kits from £275.75.
Order the casing with the door and the ironmongery in one go. Our over 700 internal doors from £30.84, over 80 white primed doors, over 350 fully finished doors from £75.00 and over 20 clearance doors from £53.00 all ship together, and our advice centre covers the rest of the job.
What about door pairs and openings wider than one leaf?
Two leaves hung in a single lining meet on a pair maker, which closes the joint between them and gives the doors something to shut against. If the opening is wider than a pair, an internal side panel fills the extra width in the same face and finish, and the outside equivalent is a side panel for external doors.
Outside the house the rules change
Everything above concerns internal openings. An external opening needs a heavier rebated section with a cill that throws water clear of the threshold, which is a different component entirely, and fitting a new external leaf into a tired existing frame is the most common reason a good door fails early. Specify from external frames and treat the frame, the threshold and the seals as one assembly.
Prices and product counts are correct at the time of writing and are subject to change. Manufacturer fitting instructions always take precedence over general guidance, particularly on fire rated assemblies. Regulatory requirements vary by building, use and location. Confirm your specific obligations with your local building control body, a competent fire risk assessor or a suitably qualified professional before ordering or carrying out work.