Taking a wall out to open up a kitchen or living space is one of the most common renovation jobs, and one of the most misunderstood. Here is what actually has to happen when the wall is holding something up.
First: is it actually load-bearing?
A load-bearing wall carries weight from above, the roof, the ceiling, or a floor over it, down to the footings. A non-load-bearing wall just divides the space. You cannot always tell from inside the room: walls that run at right angles to the ceiling joists or trusses above, walls that sit over a beam or a thickened footing, and walls in the middle of the span are the usual suspects.
Getting this wrong is expensive and dangerous, so the honest answer is that a wall gets confirmed by looking at the structure above it and, where there is any doubt, by an engineer, not by a guess.
The engineer and the beam
Once a wall is confirmed as load-bearing, a structural engineer works out what replaces it. That is almost always a beam, an LVL, a hardwood member or a steel beam, sized for the load and the span, sitting on posts or piers that carry the load down to something solid.
The engineer provides a detail: the beam size, what it bears onto, and how it is fixed. That detail is what the carpentry is built to, and it is also what a certifier or council will want to see.
Temporary support comes first
Before the wall comes out, the load it carries has to go somewhere. That means temporary propping, acrow props and bearers set up to take the weight while the wall is removed and the new beam goes in. Skipping or under-doing the temporary support is where these jobs go wrong.
Approvals and sign-off
Structural work like this usually needs approval. In NSW that is often a Complying Development Certificate or a Development Application, with a private certifier or council involved, and the engineer’s detail forms part of it. The exact path depends on the property and the scope.
Typical sequence:
- Engineer’s structural detail for the beam and supports
- Approval pathway confirmed (certifier or council) before work starts
- Temporary propping in place before the wall is touched
- Beam installed, packed and fixed to the engineer’s spec
- The opening lined, and the rest of the reno tied back in
The framing and the beam install is the carpentry. The load path, the beam size and the approval are things worked through with your engineer and certifier, so the job is done to the detail and signed off, not just done quickly.