What keeps an internal masonry wall supported?

Internal masonry walls may obtain sideways support from properly connected cross-walls or returns, reinforced piers or cores, designed framing, or concrete roof or floor slabs. A plasterboard ceiling and cornice can also form part of a specific designed support detail. These details are not interchangeable. Establish the actual construction and connections before alteration, even if the wall carries no roof or upper-floor load.

For a building project requiring structural design, explore our structural and foundation design. An article cannot determine the cause or appropriate solution for an individual property.

Diagram comparing five ways to support an internal masonry wall, from cross-walls to designed ceiling details.

An internal masonry wall can need sideways support even where it is not carrying the roof or an upper floor. Carrying vertical load and resisting sideways movement are different functions. Before a wall, ceiling or cornice is altered, the actual support arrangement needs to be established. A non-loadbearing label is not permission to remove it.

Support can come from several places

For interconnected single-leaf masonry, identify the supports and connections specified in the construction documents. A return wall, a reinforced core, framing and a concrete slab provide support in different ways. A plasterboard ceiling with cornices is relevant only where it forms part of the designed arrangement.

The alternatives are not interchangeable. Check the position and connection of any return wall. Roof or ceiling construction can form part of a designed support arrangement, but that does not mean every visible lining provides support. An engineer needs to identify the arrangement actually present.

Check how the roof and ceiling connect

A ceiling joist and wallplate arrangement differs from a detail for non-loadbearing masonry beneath another roof and ceiling system. The roof framing, any battens and the allowance for movement under load all matter when establishing what the wall relies on.

Do not infer cornice fixing or the way a connection should be detached from the visible finish. The clearance and fixing conditions depend on the particular design. If drawings or details appear inconsistent, have the engineer resolve them before altering the wall.

Related: How much head clearance does an internal masonry wall need?

Before altering an internal masonry wall

Show the engineer where the wall sits on a plan, its material if known and what adjoins it. Provide available roof or floor drawings, records of previous alterations and photos taken without opening the construction. State whether anyone proposes to remove a return wall, replace the ceiling, change the cornice or widen an opening.

Ask which elements carry vertical load and which provide lateral restraint, including restraint to another wall. An element can matter even if it does not carry the load you first had in mind. The engineer needs to establish the actual roles and any temporary and permanent work needed.

What a crack can and cannot add

Record when separation or changing contact was noticed. This may help the engineer but does not establish the support arrangement or show that a ceiling connection failed. Photograph the wall and ceiling junction with nearby openings in view as well as any close-up of the crack.

Do not cut the wall top, remove cornices or disturb connections to check whether the wall carries load. Keep away from apparently unstable, leaning or bulging masonry and seek prompt professional assistance. In immediate danger, use the appropriate emergency response.