Risks of DIY Load-Bearing Wall Removal

If you remove a load-bearing wall without proper support, the floor or roof it carried has nowhere to go but down: sometimes suddenly during demolition, more often as a slow sag that cracks ceilings, tilts floors and shifts load onto framing that was never designed for it. The physical risk is only part of it. A DIY removal without a design and a building permit can also mean stop-work orders, an order to uncover finished work, and problems when you sell or insure the house. None of that means a homeowner can't be involved. It means the design, shoring, load path and permit can't be skipped.

This post covers what actually goes wrong when a load-bearing wall comes out the wrong way, what "removal kits" do and don't do, and the legal and resale side in Ontario. If you're planning a removal, our step-by-step guide to removing a load-bearing wall and installing a beam shows how it's done properly.

What happens when the support comes out

A load-bearing wall carries joists, and through them floors, walls, roof and snow above. Take it out and that load looks for another path.

Immediate failures. With no temporary shoring, joists that bore on the wall can drop as soon as the studs and top plate are cut. In the best case, it's a few centimetres and a lot of cracked plaster. In the worst case, a floor or ceiling comes down on whoever is underneath. Upper-floor walls carrying roof struts or point loads can release a lot of load at once.

Slow failures. More common is a removal where something holds, just not well enough:

• The joists sag along the old wall line, and the floor above dips.
• Drywall and plaster crack at the ends of the opening and across the ceiling.
• Doors and windows on the floor above start to stick or swing on their own.
• Tile floors above crack, and countertops or cabinets pull away from walls.
• The load shifts to whatever is nearest: a header that was never sized for it, a partition wall that wasn't load-bearing, or the ends of the joists themselves.

Undersized replacements. Sometimes a beam goes in, but it's guessed rather than designed. A beam that's too small deflects too much, and the floor above feels bouncy or sags. Our post on how much weight a steel beam can hold explains why beam size can't be read off a span alone.

The load path is where DIY jobs fail

The beam is the visible part. The common DIY failure is everything under it.

• Posts with no footing. A post at the end of a new beam is set on the basement slab. A basement slab can be as thin as 75 mm under the Ontario Building Code (Article 9.16.4.3) and isn't designed as a footing. Under a concentrated load, it cracks and the post sinks, taking the beam with it.
• Posts that don't line up. On a main-floor or second-floor removal, the post has to continue down through every floor to a footing. A post that stops on a floor joist crushes or bends it. Our post on removing a load-bearing wall in a two-storey or split-level covers how the load path changes by floor.
• No blocking or squash blocks. Point loads passing through a floor need solid wood or steel under them. Without it, the floor framing and subfloor crush.
• Poor connections. A beam that isn't fastened to its posts, or joists that aren't properly hung on a flush beam, can shift sideways or slip off.

What "load-bearing wall removal kits" cover

Searches for a "load bearing wall removal kit" usually lead to sets of adjustable steel shores with top and bottom plates. They are useful, and our post on temporary shoring and renting steel jack posts explains how shores are used. But a kit only addresses the temporary stage. It doesn't tell you:

• How big the permanent beam needs to be.
• How many posts it needs and what size.
• What footings go under the posts.
• How the beam connects to the posts and to the joists.
• Whether the floor under the shores can carry the shoring load.

Those come from a design. Shores set in the wrong place, on a thin slab or at the wrong height can cause the same damage as no shoring at all.

Hidden hazards inside the wall

Load-bearing walls are often where a house's services run, because they line up floor to floor. Opening one can uncover:

• Plumbing stacks and vents, which can't just be cut and capped.
• Gas lines, which only a licensed gas technician should reroute.
• Electrical circuits and junction boxes that need an electrician.
• Heating and return-air ducts.
• Hazardous materials in older homes, such as asbestos in some plasters, joint compounds and pipe insulation, or vermiculite insulation in the attic or walls. In an older house, have suspect materials tested before demolition.

Physical work brings its own risks too: lifting a steel beam into place, working on ladders under a partly supported ceiling, and dust from demolition.

The permit side in Ontario

Under section 8 of Ontario's Building Code Act, no one may construct or demolish a building without a permit from the chief building official, and the Act defines "construct" to include the material alteration or repair of a building. Removing a load-bearing wall falls squarely in that. What happens if the work is done without one:

• Order not to cover, or to uncover. Under section 13 of the Act, an inspector can prohibit covering work pending inspection, and the chief building official can order work that was covered without a permit to be uncovered for inspection, at the owner's expense. That can mean opening a finished ceiling.
• Stop-work order. If an order isn't complied with, section 14 allows an order stopping all or part of the work.
• Unsafe building orders. Under section 15.9, a building that is structurally inadequate can be the subject of an order setting out repairs.
• Offences and fines. Contravening the Act or failing to comply with an order is an offence under section 36.
• Orders on title. Some orders can be registered in the land registry office, so a later buyer is deemed to have been served with them.

Beyond the Act, unpermitted structural work tends to come up at sale, when a buyer's home inspector or lawyer asks for permits, and can complicate insurance claims. Ask your insurer how they treat unpermitted renovations before you start.

The permit process itself, including what drawings the municipality expects, is covered in permits for load-bearing wall removal in the GTA. Who can prepare those drawings, and when it has to be an engineer, is in do you need a structural engineer to remove a wall.

What a homeowner can safely take on

A DIY-minded homeowner can still save effort and stay safe by splitting the job sensibly:

• Get the design and permit first. That fixes the beam, posts, footings and connections before anything comes down.
• Leave shoring, removal and beam setting to people who do it regularly, or follow the design exactly if you do it yourself, and book inspections at each stage.
• Handle the non-structural work: clearing the room, protecting floors, finishing, painting and trim.
• Use licensed trades for gas, electrical and plumbing changes.

Steel for a wall removal done right

We fabricate steel beams and HSS posts with welded plates, drilled to your designer's or engineer's drawings, and we supply and install basement beams and posts across the GTA and Ontario. Send us your drawings for a quote, or see the beams and posts we fabricate.