Lintels and BeamsLintels and Beams

The term to bridge an opening is a wide The term to bridge an opening is a wide ranging expressions to describe many ranging expressions to describe many methods by which a wall is supported methods by which a wall is supported across a window opening such as a across a window opening such as a windows or door. windows or door.

No opening must be bridged without No opening must be bridged without support. support.

Neither brick or stone is capable of Neither brick or stone is capable of spanning any distance unsupported. The spanning any distance unsupported. The most common method of providing this most common method of providing this support is the lintel. support is the lintel.

Lets now look at the main types of Lets now look at the main types of lintels used in construction todaylintels used in construction today

Steel LintelsSteel LintelsMinimum seating of 150mm

Perforations to form a key for plaster.

Domestic properties nowadays almost always use pre-fabricated steel lintels.

These are manufactured into a great variety of shapes and sizes to suit the different designs of the building.

This type of lintel has great advantages in terms of lightness, strength and ease of use.

There are lintels designed for heavy loads, eaves lintels and custom lintels to suit a variety of design considerations

You can also use a combination of different materials if you want, the external leaf may be a steel lintel and the internal a concrete type.

Pressed Steel LintelsPressed Steel Lintels

Examples of box lintels in use. All this internal work will later be plastered

Cavity lintel used for the external and internal walling

Section through a steel cavity Lintel

Note the cavity tray and insulation

Steel Cavity LintelsSteel Cavity LintelsNote the insulation material and also the different thicknesses

The use of insulation helps maintain the required ‘U’ values

Pressed Steel Cavity Lintel. Only the underside of the lintel is visible on completion

Minimum seating 150mm

Cavity wall lintel are suitable for most domestic and small commercial developments and framed structures

They come supplied with insulation and have perforations to provide a plaster key. Housing lintel require a separate DPC.

Steel Cavity LintelsSteel Cavity Lintels

Reinforced Concrete LintelsReinforced Concrete LintelsThe use of reinforced concrete lintels is very common. They have many advantages over other forms of lintels, the main one being the adaptability to suit any size or shape.

Concrete though strong in compression, is very weak in tension and for this reason reinforcing rods are placed in the lower part of the lintel in order to absorb the tension and provide the needed strength.

All concrete lintels are made by placing wet concrete into a timber or metal mould of the required size, the sides are removed when the concrete has set.

This process is known as casting, and lintels can be either pre-cast which means they are delivered to site ready to use or cast- in situ where the lintel is cast into the position they are to take in the building.

Lintels in storage on wooden pallets

These are pre-stressed lintel cut to length exposing the reinforcement cables

Lintel in position

Concrete LintelsConcrete Lintels

Storing concrete lintels should be done safely due to the weight of the lintels. They should be stored on battens, banded to ensure safe removal and transport

Boot Type Lintel:

Note the position of the reinforcement in the lintel and the position of the DPC

Welsh ArchWelsh Arch

Used for small spans the adhesive and the shear properties of a good mortar will often provide the necessary strength, the welsh arch being a good example.

Mainly used when pipes have to run through the walling

An alternative arrangement for small openings using a slate bridge

Line of cut

Specified Lintel for vertical Slate hangingSpecified Lintel for vertical Slate hanging

Custom LintelsCustom Lintels

These lintels can be supplied for complex features such as corbels and other architectural details.

Bay, Corner and cantilevered corners are available in addition to such shapes as shown opposite.

Apex arch, Corner and Radius lintels.

Most manufactures will offer advise on the most appropriate lintel or alternative method of support.

Radius Corner

Apex

Examples of Lintel ProfilesExamples of Lintel Profiles

Good Site PracticeGood Site Practice

Lintel being InstalledLintel being Installed

Ensure lintel is level along its length

Ensure a nominal 150mm bearing at each end

Check lintel for damage

Ensure lintel is fully bedded on mortar

Opening or clear span

Good Site PracticeGood Site Practice

Cross section of walling in preparation for beddingCross section of walling in preparation for bedding

Ensure the blockwork overhang does not exceed 25mm.

Ensure lintel is level along its width

Masonry above lintel should be allowed to cure before applying loads

Outer leaf Inner leaf

Ensure wall dimensions are correct

Where possible build inner and outer leaves together

Ensure you have selected the correct lintel according to the loadings you are placing upon it.

And that no more than half

The safe working load (SWL) is carried by the outer leaf where the lintel carries an external cavity wall.

Selecting a LintelSelecting a Lintel

Selecting a LintelSelecting a Lintel