A lintel beam is an essential structural element used to support and transfer load above an opening to the adjacent masonry, and then down to the foundations below. Lintels are most often made from reinforced concrete (including pre-stressed units) or steel, in a range of configurations suited to different applications.
Lintel beams are used below ground at foundation level to allow services to pass through, or as part of other building elements such as protecting drainage runs or sub-floor vents. Above ground, they are commonly used over doorways and window openings, or below other supporting structures up to roof level.
This guide is intended as general information only and should not be used as a substitute for project-specific structural design or professional advice.
What Does a Lintel Beam Actually Do?
A lintel transfers the load above an opening to the walls on either side. A building may look static, but in reality it is always subject to movement from wind, temperature change, settlement, and day-to-day use.
A lintel has to accommodate these forces over time. Where movement becomes excessive, signs may begin to appear in the surrounding masonry, such as cracking or distortion around openings.
Lintels may also be designed to carry live loads. Where a lintel sits below an upper storey, it may need to support not only masonry and structural elements above, but also the effects of occupation and use.
Learn more about this in our guide How Much Weight Can a Steel Lintel Support?.
What Happens if a Lintel Stops Doing Its Job?
If a lintel is undersized, poorly installed, or has deteriorated over time, the structure may begin to show signs of stress. Masonry joints may crack, and windows or doors may stop operating as smoothly as they once did.
In some cases, particularly in older work, builders may have relied on a window or door frame for support where a proper lintel should have been installed. Where that happens, distortion can develop around the opening over time.
Some steel doors and window systems include structural support within the frame itself, but these are typically specialist products and are less common in domestic construction.
When Do You Need a Lintel Beam?
If you are planning to open up a wall between two rooms, it is important to establish whether that wall supports floor joists, roof structure, or a wall above. If it does, a lintel or another structural solution may be required, along with associated elements such as padstones.
Opening up the rear of a property may also require a new lintel arrangement, particularly where two separate openings are being combined into one larger opening. Any new doorway or window opening will typically require structural support above it.
Do You Need Lintels in a Loft Conversion?
In a loft conversion, roof windows will not usually require lintels unless masonry is involved. In most cases, the timber structure is trimmed around the opening using appropriately sized framing members to support the window and glazing.
The loft floor may also require additional structural support, and the resulting changes in loading can have implications elsewhere in the building. In some situations, existing lintels may need to be reviewed as part of the wider structural design.
Types of Lintel Beams Used in the UK
Steel Lintels
Steel lintels are widely used above ground over window and door openings. Their strength-to-weight ratio makes them well suited to cavity wall construction and to wider openings where a more compact section may be preferred. See our full range of steel lintels for available sizes and types.
A steel cavity lintel can be used to support a soldier course of brickwork above an opening. It may also support a linear bond of facing brick or blockwork that will later be rendered or otherwise finished.
On wider openings, temporary support may be required during installation to help prevent movement while the masonry above is being laid and the mortar is still curing.
Concrete Lintel Beams
The compressive strength of concrete, combined with the tensile strength of steel reinforcement, makes pre-stressed concrete lintels a common choice at foundation level. For some openings up to around three metres, a concrete lintel may also represent better value than steel.
Concrete lintels are commonly used over openings in internal blockwork walls, above garage doors, and in both inner and outer leaves of cavity walls where the face will be rendered, plastered, or otherwise finished. You can view our range of concrete lintels here.
Steel vs Concrete Lintels – Typical Comparison
The table below shows typical characteristics of steel and concrete lintels used in domestic construction. Values are indicative only and will vary depending on manufacturer, span, and loading conditions.
| Characteristic | Steel Lintels | Concrete Lintels |
|---|---|---|
| Typical span range (domestic) | 600mm – 4800mm+ | 600mm – 3000mm |
| Weight (per metre) | 8 – 25 kg/m (depending on section) | 20 – 90 kg/m |
| Typical height / depth | 100 – 215mm | 100 – 215mm+ |
| Load capacity (SWL) | 20 – 100 kN (application dependent) | 10 – 60 kN (application dependent) |
| Bearing (typical) | 100 – 150mm | 100 – 150mm |
| Thermal performance | Often insulated (cavity lintels) | Requires separate insulation detail |
| Installation | Lighter, easier to handle on site | Heavier, may require two-person lift |
| Corrosion resistance | Galvanised coating required | Inherently resistant (with cover) |
| Typical use cases | Cavity walls, wide openings, external leaf support | Internal walls, foundations, solid wall construction |
| Cost (relative) | Higher for larger spans | Generally lower for short spans |
Note: Always refer to manufacturer span tables and structural design where required. Values above are typical ranges for guidance only.
If you're unsure which type or size you need, it's often quicker to speak to someone with experience — we can help point you in the right direction before you order.
Stone and Timber
Stone and timber lintel beams are generally not used in new construction today, but they can still be found in historic or pre-First World War buildings in the UK.
How Are Lintel Beams Sized or Specified?
A lintel span refers to the overall length needed to bridge an opening while also achieving the required bearing at each end. The load above the opening influences the depth and type of lintel required.
As a rule of thumb, many lintels are designed with around 150mm bearing at each end, although this varies depending on lintel type, loading conditions, span, and manufacturer guidance. Bearing requirements should always be checked against the relevant product data before installation.
When Should You Refer to a Lintel Span Table?
Manufacturer span tables are useful for early-stage planning, estimating, and preparing a bill of quantities.
Concrete lintel span tables available here.
For Building Control approval or formal specification, final lintel selection should be based on actual loading conditions and supported by appropriate data and design input.
Common Issues Seen on Site
Insufficient Bearing
Bearing is critical to ensuring load is transferred correctly into the structure below.
Cracking Above Openings
Cracking above an opening can be an indicator that a lintel may not be performing as intended, though proper assessment is usually required to confirm the cause.
Poorly Executed Retrofits
If you're dealing with an existing opening or replacement, our guide on how to fit a fireplace lintel covers the process in more detail.
When Should a Structural Engineer Be Involved?
Structural changes such as removing load-bearing walls or creating larger openings should be properly assessed before work begins.
If you're interested in learning more about lintels, check out our complete guide to lintels in the UK.
Get in Touch
For all your project’s lintel requirements, Wade has the experts on hand to answer your queries. Call or email us today to find out how quickly we can deliver what you need to site.
