What is a door lintel?
A door lintel is a load-bearing element that sits above a door opening in a masonry wall. Lintels above doors are a structural requirement in any load-bearing wall as, without one, the masonry above the opening has nothing to support it. Its job is to carry the structural weight above, whether that is brickwork, blockwork, a floor or a roof, channelling it down to the solid masonry on either side.
A missing or failing lintel above a door frame puts the surrounding structure at risk. Cracks above door openings, a sticking door or visible bowing in the brickwork are all warning signs that the lintel may not be doing its job. If you have the correct product from the outset, you can avoid these problems entirely.
For a full overview, visit our guide to steel lintel solutions for masonry cavity walls.
Types of door lintels
Cavity wall lintels
Cavity wall lintels are built to bridge both leaves of a cavity wall across a door opening. With over 80 products covering cavities from 50mm to 205mm, we have a specification to suit most domestic and commercial door openings.
Browse cavity wall lintels | Buy direct
Single leaf and interior lintels
Single leaf lintels support one leaf of masonry, the outer leaf, above a door opening. Available in standard and light duty options for a variety of applications.
Single leaf lintels | Buy direct
Interior lintels support one leaf of masonry above an internal door opening. Available in standard and heavy duty applications for a variety of loading applications. With its integral plaster key built into the lintel, this allows for finishes to be easily applied.
View interior wall lintels | Buy direct
Thermally broken lintels
A thermally broken lintel is built to reduce heat loss at the door opening. Standard steel lintels can create a cold spot in the wall where heat escapes, known as a cold bridge. The built-in insulation in a thermally broken lintel breaks this path, which helps to keep your home warmer and meet modern energy efficiency standards.
Explore thermally broken lintels
Stainless steel lintels
Some building locations and applications place greater demands on lintel materials over time. A stainless steel lintel resists corrosion where standard galvanised steel may not, which makes it the preferred specification for seafront properties, industrial settings and buildings with long whole-life maintenance requirements.
See stainless steel lintels
Semi-circular arch lintels
For non-standard or decorative door openings, including arched entrances, Catnic offers special arch lintels manufactured to order. These are tailored to your specific project requirements and available on request.
View semi-circular arch lintels | Get a quote
If you’re looking for lintels for window openings, explore our window lintels range.
What size door lintel do I need?
The right door lintel size depends on three factors:
1. The width of the door opening (the span)
2. Whether the wall is cavity, single leaf or solid construction
3. The structural loads the lintel must carry, including any floors or roofing above
The lintel needs to sit on solid masonry on both sides of the opening, at least 150mm on each side. This is called the end bearing. To work out the minimum lintel length you need, take the clear width of the door opening and add 300mm (150mm for each side)
Example: a 900mm wide door opening would typically require a lintel of at least 1200mm.
Wider openings, such as bifold or patio doors, or those carrying heavier loads from floors or roofing above, will need a heavier-duty specification. For these applications, you must carefully consider how the lintel sits within the full wall construction before you select a product.
For further help, read our Which lintel do I need? guide or contact our technical team to discuss your specific requirements.
FAQs about door lintels
A door lintel is a structural element that bridges the gap above a door opening and transfers the weight of the wall above down to the masonry on either side. A missing or undersized lintel leaves the masonry above the door opening unsupported. Over time this can lead to cracking, movement or, in severe cases, structural failure. Every door opening in a load-bearing wall requires a correctly sized lintel.
It doesn’t matter if you are carrying out a door lintel replacement or installing for the first time; always start by assessing the extent of the work. Cracking or movement around the door frame may mean the lintel has failed, but a structural engineer should confirm this before work begins.
The wall above the opening must be fully propped before removing any masonry. Once the old lintel is out, check the bearing surfaces on both sides are sound and level before the new lintel goes in. A minimum end bearing of 150mm on each side is essential. The masonry can be put back once the lintel is correctly positioned, but allow the mortar to cure fully before removing props.
You should install a lintel for a door opening before the door frame goes in, as part of the structural build. The masonry above needs to be adequately supported throughout. Once the lintel is in position (level, with full bearing on both sides), the brickwork or blockwork can be built up. You then fit the door frame into the completed opening beneath. See our guide to installing steel lintels for more details.
Catnic offers a full range of lintels for doors to suit different wall constructions and load requirements, including cavity wall, single leaf, thermally broken, stainless steel lintels and more. Semi-circular arch lintels are also available for non-standard openings. All standard Catnic door lintels are BBA approved and available to buy direct. Special sizes and specifications are available manufactured to order.
The lintel above a front door needs to be specified carefully, as front door openings are usually wider than internal doors and may carry greater loads from the wall above. Normally, the lintel should extend at least 150mm beyond each side of the opening. For most standard front door openings, add 300mm to the clear opening width. If the opening supports significant loads, such as a floor or roof above, contact our technical support for guidance on the correct specification.
Cracking in the masonry above the opening, bowing or bulging brickwork, or the door frame becoming distorted or difficult to open and close are all common signs that a lintel above a door frame may need replacing . If you see any of these, you should get a professional assessment, and always make sure a structural engineer investigates the root cause before any remedial work is carried out.
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