Concrete Prestressed Lintels are heavy-duty structural beams engineered with internal high-tensile steel wires that are put under tension (prestressed) before the concrete sets.

They are primarily used for:

• Supporting Masonry Over Openings: Spanning the gap above doors, windows, and garage openings in internal or external brick and blockwork walls to carry the heavy load of the structure above.

• Carrying Heavy Floor & Roof Loads: Supporting floor joists, concrete floor planks, and roof trusses that sit directly above door or window openings.

• Preventing Wall Cracking & Structural Failure: Distributing vertical weight evenly down into the surrounding load-bearing walls on either side of an opening, preventing sag, masonry cracking, or wall collapse.

• Fire-Resistant Structural Support: Providing high fire resistance in structural wall openings for residential, commercial, and industrial buildings.

Available for collection from our Rugby branch or local delivery using our own fleet.

Delivery is kerbside and the final offloading position is always subject to safe access and the driver’s discretion.

Please tell us before delivery about:

• Narrow roads or restricted entrances
• Parked vehicles or limited turning space
• Overhead cables, trees or other obstructions
• Soft, sloping or unsuitable ground
• Any other access concerns

Enter your postcode on the product page to check your delivery area. We’ll confirm the delivery date after your order is placed.

How much end bearing is required for a prestressed concrete lintel?

Under UK Building Regulations (Approved Document A), the minimum end bearing on solid masonry depends on the opening size:

• Openings up to 1.2m: Minimum 100mm bearing at each end.

• Openings over 1.2m to 3m: Minimum 150mm bearing at each end.

• Openings over 3m: Minimum 200mm bearing at each end (or as specified by a structural engineer).

Which way up should a prestressed concrete lintel be installed?

Prestressed lintels must be installed with the high-tensile steel tension wires situated near the bottom edge of the unit. Most manufacturers stamp the word "TOP" onto the upper surface. Ensure this mark faces upwards during installation so the internal steel properly resists downward bending forces.

Can prestressed concrete lintels be cut to length on site?

Yes. They can be cut to required sizes using a high-speed angle grinder equipped with a diamond cutting disc. Always wear appropriate PPE (dust mask, eye protection, ear defenders) as cutting concrete releases fine silica dust and can spark if the blade contacts the high-tensile steel wire inside.

Is temporary propping required during installation?

For spans exceeding 1.2m, temporary vertical timber or steel props should be placed underneath the lintel (spaced at maximum 1.2m intervals) until the wet mortar and masonry laid above have fully cured. This prevents deflection while the composite wall structure gains strength.

Do concrete lintels need a damp-proof course (DPC)?

When used in external cavity walls, a flexible DPC tray (or cavity tray with weep holes) must be installed above the concrete lintel. This ensures any moisture penetrating the outer brickwork leaf is safely directed outward away from the internal wall.

The choice between a concrete and steel lintel depends on whether you are building an internal single-leaf wall or an external cavity wall, as well as your budget, load requirements, and site handling preferences.

• Choose a Concrete Lintel if you need a cost-effective solution for internal walls or single-leaf masonry. Prestressed concrete lintels are significantly cheaper than steel, offer high fire resistance without extra treatment, and will never rust or corrode. They match the density of blockwork walls perfectly, though they are heavy to handle manually.

• Choose a Steel Lintel if you are building an external cavity wall or need to support high structural loads. Galvanized steel cavity lintels (like box or catnic lintels) bridge both leaves of a cavity wall in a single, lightweight unit, reducing thermal bridging and simplifying installation. They are also ideal for wide openings where low profile height is required.