Structural Openings In Masonry: Why Skill Matters

Creating a structural opening in a masonry wall is one of the most technically demanding tasks in building construction.

Whether it is a new window or door opening in a residential property, a wide vehicular access in a commercial building or a series of openings as part of a large development project, the work requires careful planning, correctly specified materials and a high level of practical skill to execute safely and to the required standard.

What Is A Structural Opening?

A structural opening is any opening created in a load-bearing masonry wall, whether for a door, window, garage door, vehicular access or any other purpose.

Because the wall carries load from the structure above, including floors, roofs and upper storeys, removing masonry to create an opening introduces a gap in the load path that must be bridged by an alternative structural element. This element is the lintel.

The Role Of The Lintel

A lintel is a horizontal structural member, typically made from steel, precast concrete or reinforced concrete, that spans the width of the opening and transfers the load from the wall above down to the masonry on either side.

The lintel must be correctly specified to carry the loads imposed upon it, correctly sized for the width of the opening and correctly bedded into the masonry on both sides to transfer those loads safely.

Choosing the wrong type or size of lintel, or installing it incorrectly, can result in deflection, cracking or, in serious cases, structural failure of the wall above the opening.

The specification of lintels for structural openings should always be confirmed by a structural engineer, particularly where the opening is wide, where the loads above are significant or where the masonry is of an unusual type or construction.

How Are Structural Openings Created In Masonry?

Temporary Support

Before any masonry is removed to create a new opening, the structure above must be temporarily supported to prevent it from moving or settling whilst the permanent lintel is being installed.

This is typically achieved using a system of acrow props and needle beams which transfer the load from the wall above to the floor or ground on either side of the proposed opening. Installing adequate temporary support is a critical safety step that must not be rushed or underestimated.

Cutting & Removing The Masonry

Once temporary support is in place, the masonry within the proposed opening is carefully cut and removed.

This work requires precision to achieve clean, accurate cuts at the correct dimensions and to avoid damaging the surrounding masonry or disturbing the temporary support system.

On older properties, the masonry may be of variable quality or construction, requiring additional care and adaptability from the team carrying out the work.

Installing The Lintel

With the masonry removed, the lintel is lifted into position and carefully bedded onto a full mortar bed on both sides of the opening, making sure it has the correct bearing length on each side as specified by the structural engineer.

The masonry above the lintel is then reinstated or made good as required, and once the mortar has achieved sufficient strength the temporary support can be removed.

Making Good The Opening

Once the lintel is installed and the temporary support removed, the opening is made good to receive the window, door or other fitting.

This involves cleaning up the reveals, checking that the opening is plumb, square and to the correct dimensions and making any adjustments needed before the frame is fixed in place. The quality of this finishing work directly affects how well the window or door fits and performs over its lifetime.

Why Skill & Experience Matter

Creating a structural opening in masonry carries real risks if it is not carried out correctly. Inadequate temporary support can allow the structure above to move before the permanent lintel is installed.

An incorrectly specified or poorly installed lintel can result in cracking, movement or structural failure. Inaccurate cutting can affect the fit and performance of the finished opening for the life of the building.

Experienced bricklayers and masonry contractors who have carried out structural opening work across many projects understand the risks, follow the correct sequence of operations and have the practical skills to deliver a safe, accurate and well-finished result.

On a large development where multiple openings need to be created to a consistent standard and tight programme, having the right team in place is essential.