Span
The width of the opening the lintel has to bridge.
The Lintel Superstore guide
Lintel Superstore. The plain-English guide to lintels.
What a lintel is, why every opening needs one, which type to use and where to buy it, written for homeowners, self-builders and trades.
Last reviewed September 202601 · The basics
What is a lintel?
A lintel is a beam that sits above an opening in a wall, such as a window or door, and carries the weight of everything built above it. It rests on the wall at each end and spans the gap between, passing the load from the masonry above safely into the wall on either side.
Without one, the bricks or blocks over the opening would have nothing to rest on. Most lintels today are galvanised steel or concrete, made to carry a known load over a known width, and in a cavity wall they also carry a tray that keeps water out of the inside of the wall.
- 1Opening
- 2Lintel
- 3Bearing (each end)
- 4Load from above
- 5Cavity tray
Glossary
Five words worth knowing
You'll see these terms on load tables, product pages and in conversations with your builder.
Bearing
The length of lintel that rests on the wall at each end.
Load
The weight the lintel carries: masonry, floor joists, roof and anything else above it.
Leaf
One skin of a wall. A cavity wall has an outer leaf and an inner leaf.
Cavity
The gap between the two leaves of a cavity wall.
02 · Why it matters
Why you need a lintel
It carries the wall above.
The masonry over an opening cannot support itself. A lintel carries that weight, plus anything bearing on the wall higher up, such as floor joists, a roof or another storey, and passes it into the wall on either side of the opening.
What happens without one
When a lintel is missing, undersized or has failed, the signs appear slowly and then all at once.
- Stepped or diagonal cracks spread from the corners of windows and doors.
- Frames go out of square, so windows stick and doors jam.
- Brickwork sags in the middle of the opening or bows outward.
In a cavity wall, an old lintel without a proper tray can let damp through to the inside. Fitting the right lintel from the start is far cheaper than putting any of this right.
Common jobs
When you'll need one
Creating a new opening for a window or door
Building an extension
Knocking through between two rooms
Converting a garage
Replacing a rotten timber lintel in an older property
Regulations
The rules
In England and Wales, creating or widening a structural opening is controlled work under the Building Regulations. Approved Document A covers structure and expects every opening to be properly supported, so you will usually need to notify Building Control, and for larger openings or unusual loads, a structural engineer's calculation.
Lintels themselves are made to BS EN 845-2, the British and European standard for lintels, so a lintel from a reputable manufacturer comes with published load tables you can rely on.
Approved Document ABuilding Regulations — structure
BS EN 845-2The British and European standard for lintels
03 · Types
The different types of lintel
By material
Section · steel profile
Galvanised steel
The most common choice for external walls in new work. Steel is pressed into a profile that is light to handle but very strong for its weight, then hot-dip galvanised to protect it from rust. Many cavity-wall versions have insulation and a damp-proof course built in.
Browse steel lintels →Section · stainless profile
Stainless steel
The same profiles as galvanised steel, made from stainless steel for sites where corrosion is a real risk: near the coast, around swimming pools or in industrial atmospheres. It costs more, so it is specified only where it is needed.
Browse stainless lintels →Section · tensioned wires
Prestressed concrete
Concrete lintels with steel wires tensioned inside them, making them far stronger than plain concrete. Cheap, fireproof and rust-proof, they are mostly used for internal walls, garages, outbuildings and the inner leaf of cavity walls. They need propping until the masonry above has cured, typically around a week.
Browse prestressed lintels →Section · bars + links
Reinforced concrete
A heavier concrete lintel with steel bars cast inside. Strong on its own without relying on the masonry above, so it suits heavier loads and longer spans where a prestressed lintel would not do. Longer lengths often need lifting equipment.
Browse reinforced lintels →Elevation · timber beam
Timber
Common in houses built before the twentieth century. In an old brick or stone house you may well find a timber lintel behind the plaster above a window or door. Timber works until it rots, which is why it is so often the reason for a replacement job.
Find a replacement →Elevation · dressed stone
Stone
Found in period and heritage properties, where a single dressed stone spans the opening. Stone is limited to short spans, and on listed buildings you may be required to repair or replace like for like.
Heritage options →By application
Pick by where it goes
The wall a lintel sits in decides its shape as much as the load does. Start here, then check the load class.
Cavity wall lintel ↗
For external walls with an outer leaf, a cavity and an inner leaf. The standard choice for most house openings, made in standard, heavy-duty and extra-heavy-duty versions and for different cavity widths.
Solid wall lintel ↗
For older solid brick or stone walls with no cavity. Wide enough to carry the full thickness of the wall.
Single leaf lintel ↗
For walls made of one skin, such as internal walls, garages and garden walls.
Eaves lintel ↗
For openings that sit right under the roof line, shaped so the roof can bear on the wall at eaves level.
Box lintel ↗
A closed rectangular steel section for internal walls.
Angle lintel ↗
An L-shaped steel section that supports the outer leaf only, where a separate beam carries the inner leaf.
Insulated or thermally broken lintel ↗
Reduces the cold bridge a plain steel lintel creates across a cavity and helps meet Part L of the Building Regulations on energy.
Side by side
Comparison
| Material | Typical use | Strengths | Drawbacks |
|---|---|---|---|
| Galvanised steel | External cavity walls and most new-build openings | Light, strong, widest range, damp-proofing and insulation built into many profiles | Cold bridge unless insulated. Coating can be damaged by rough handling |
| Stainless steel | Coastal, exposed and high-corrosion sites | Longest life, no maintenance | Highest cost |
| Prestressed concrete | Internal walls, inner leaves, garages and outbuildings | Cheap, fireproof, cannot rust | Heavy. Needs propping while the masonry cures |
| Reinforced concrete | Heavier loads and longer spans in concrete | Strong without relying on the masonry above | Very heavy. May need lifting gear |
| Timber | Older houses | Easy to cut and fix | Rots and sags over time. Not for new masonry walls |
| Stone | Period and heritage buildings | Matches the original fabric | Short spans only. Costly and needs a specialist |
04 · How to choose
How to choose the right lintel
Six checks, in order. Work through them and you'll know exactly what to ask for.
- 01
Measure the opening
Measure the structural opening, not the window or door frame. This is the span.
- 02
Add the bearing at each end
The lintel must rest on solid masonry at both ends. The usual minimum is 150mm each end, so lintel length is the span plus 300mm, rounded up to the next standard length.
- 03
Work out the load class
Is it a few courses of brick under a window, or a full storey with floor joists and a roof? Standard-duty suits many domestic openings; heavy-duty and extra-heavy-duty cover the rest.
- 04
Match the wall build-up
Cavity, solid or single leaf? Note the leaf thicknesses and measure the cavity width carefully, because steel cavity lintels are made for specific widths and the wrong one will not fit.
- 05
Decide internal or external
External lintels have to manage damp as well as load, so a steel cavity lintel with a built-in damp-proof course is standard. Internal openings can often use a simpler prestressed concrete lintel.
- 06
Check the load tables, or ask an engineer
Every reputable manufacturer publishes the safe load for each lintel at each span. Where a floor or roof bears on the wall, or anything about the opening is unusual, have a structural engineer confirm it.
Worked example
A new window is going into an external cavity wall: 100mm brick outer leaf, 100mm cavity, 100mm block inner leaf. The structural opening is 1,800mm wide. Above it are three courses of brick, then the first-floor joists bearing on the inner leaf, then another storey and the roof.
- Span
- 1,800mm.
- Length
- 1,800mm plus 150mm bearing each end is 2,100mm, a standard length.
- Load class
- The floor joists bear on the inner leaf so must be considered. Check the manufacturer's load tables SWL (safe working load) and consult a structural engineer to calculate the load of your opening.
- Wall build-up
- A cavity lintel made for a 100mm cavity.
- External
- So a steel cavity lintel with a built-in damp-proof course.
Result
A 2,100mm standard duty insulated steel cavity lintel for a 100mm cavity, confirmed against the manufacturer's load table. Building Control is notified before work starts and the lintel is checked by a structural engineer.
05 · FAQs
Common questions about lintels
Straight answers to the questions homeowners and self-builders ask most.
Fitting a lintel is structural work. The wall above has to be temporarily propped, the opening cut, the lintel bedded level on mortar at both ends and the masonry made good, in the right order. A competent builder does this routinely. Unless you have done it before, it is a job to hire out.
If you are creating a new opening or making one wider, yes in most cases. Replacing a failed lintel like for like in the same opening may not need an application, but a quick call to your local Building Control team will confirm.
A galvanised steel lintel installed correctly is designed to last the life of the building, and concrete lintels are just as long-lived. Timber lintels in older homes are the exception, because they rot where damp gets in.
Neither is better in every case. Steel is lighter, easier to handle, has insulation and damp-proofing built in, and is the standard for external cavity walls. Concrete is cheaper, fireproof and ideal for internal walls, garages and outbuildings. Many houses use both.
Almost always. Even in a wall carrying no load from above, the blocks over the door need supporting, and a small prestressed concrete lintel is the usual answer. In a timber stud wall, the head of the door frame does the job instead.
Weep holes are small gaps in the mortar joints in the brick course sitting on a cavity lintel. Water running down inside the cavity lands on the lintel's damp-proof course and drains back out through them. Never block or fill them.
A stepped or diagonal crack from the corner of an opening is the classic sign of a lintel problem: a timber lintel that has rotted, a steel one that has corroded, or an opening that never had a proper lintel. Have it looked at by a surveyor or structural engineer before deciding on a fix.
06 · Where to buy
Where to buy lintels in the UK
Lintels are sold by specialist online suppliers, manufacturers, national builders' merchants and DIY chains. Here is where to look, and what each is good for.
UK Lintels
Specialist online supplierOver 1,500 lintels online, next-day delivery available, and guaranteed delivery dates shown at checkout before you buy.
Visit site →Homebase
DIY chainAround 500 lintels online with free delivery, supplied through a trusted partner. Standard delivery 2 to 8 working days.
Visit site →B&Q
DIY chainAround 500 lintels online with free delivery, most through a verified seller. Standard delivery 3 to 5 working days.
Visit site →MKM
Builders' merchantLarge online range, though the products available depend heavily on which local branch you select. Standard delivery 5 to 10 working days.
Visit site →Catnic
ManufacturerManufacturer selling direct. A small range of profiles in various lengths, delivered through a third party.
Visit site →Travis Perkins
Builders' merchantAround 100 lintels online, made to order through your local branch, which will contact you with a delivery date.
Visit site →Jewson
Builders' merchantAround 90 lintels online. Minimum spend for delivery and you can select a preferred delivery date at checkout.
Visit site →Lintels.co.uk
Specialist online supplierOver 1,000 lintels online. Longer lead times of 10 to 18 working days depending on brand, and the sales office asks you to call before ordering.
Visit site →Local builders' merchants
IndependentMost independent merchants stock common sizes of steel and concrete lintel for collection, and can order others in.
Find one near you →Information checked September 2026. Delivery times and stock vary by location and product.
Lintel Superstore is operated by UKLintels Ltd.
Last reviewed September 2026