Bearer and joist repairs under Toowoomba homes

What bearers and joists are, and why they go

Bearers are the heavy timbers that run along the tops of the stumps. Joists run across the bearers, closer together, and the floorboards are fixed to the joists. In a Toowoomba house built before the 1970s the lot is hardwood, and all of it has spent decades above red loam or black clay with whatever air the battens let through. Bearers rot where they sit on a stump that is holding water, where a leaking shower or a downpipe discharging onto the ground has kept one corner wet, and where the end of the bearer is let into a brick pier or buried under a verandah. Joists rot under bathrooms and laundries, at their ends on an outside bearer, and wherever the floor above has been wet for years. Termites, which QBCC says are a problem throughout Queensland, take the rest.

A rotted bearer is why a floor can be bouncy or dipped between two stumps that are themselves fine. It is also why a quote that only counts stumps is only half a quote.

When it is found

Almost always during restumping. The battens are off, the house is on jacks, the crew is under the floor with a torch, and the bearer that looked sound from the side is soft when it is probed. That is the cheapest moment to replace it and the worst moment to argue about price, which is why a restumping quote should say in advance how bearer and joist work is charged: per metre of bearer, per joist, and whether lifting the floor is included. The restumping page covers the sequence.

It is also found by building and pest inspectors before a sale, by pest controllers following termite mud tubes up from a stump, and by renovators lifting a bathroom floor in a Harristown cottage to find there is not much holding it up. In a region where 38.4% of urban households rent, there is a fourth route: a tenant reports a soft spot by the shower, and by the time the property manager has it looked at, a leak that started in the storm season has had a whole year to work on the joists.

Whoever finds it, the same rules apply to fixing it. Over $3,300 the work needs a QBCC licence in a class that covers building work on a house, which is Builder Low Rise or higher; the historical repairs-and-maintenance class cannot alter a loadbearing member, and a bearer is one. Between $3,301 and $19,999 it is a Level 1 contract, at $20,000 or more a Level 2, and the Queensland Home Warranty Scheme applies above $3,300, with structural defects covered for 6 years 6 months. Bearer and joist work is what most often pushes a small partial restump across the $3,300 or the $20,000 line part way through, which is another reason the rate for it belongs in the contract from the start rather than on a variation at the end.

How the repair runs

1. Find the extent. Rot is probed along the bearer until sound timber is reached. Half a metre of soft timber at a stump often means a metre and a half comes out.
2. Support the floor. Jacks and props carry the joists either side of the section being replaced, so the floor above does not drop while the bearer is out.
3. Cut out and replace. The rotten length is cut back to sound timber over a stump, and a new hardwood bearer of the same section is fitted, scarfed and bolted to the old with galvanised bolts and a splice plate, sitting on the ant cap of the stump below.
4. Joists. Rotted joists are cut out and new hardwood joists fitted in galvanised hangers, or sistered alongside the old where the old is sound enough to help. Under wet areas the floor comes up to do it, and the plumber fixes the leak before the new timber goes in.
5. Treat and ventilate. Where termites were the cause, a licensed pest controller treats the house; termite management is a QBCC occupational licence regardless of value. Where damp was the cause, the ground is regraded and the downpipes connected; otherwise the new timber is on the same clock as the old.
6. Approval. A bearer is a structural component, so replacing one is at least a repair affecting a minor structural component, and the certifier decides whether it is accepted development or part of a building development permit. Done together with a full restump it sits under the restump's permit. Done on its own, ask a licensed building certifier; council's duty certifier is at the Toowoomba Service Centre on Tuesdays and Thursdays, 9 to 4.30.

What Toowoomba adds

Wet-area corners after the storm season. The bathroom and laundry corner of a Harristown, Wilsonton or Drayton cottage is almost always the worst. The Bureau's city record puts January at 132.1 mm and the black clay under the flat suburbs holds that water for weeks, so a shower that has leaked for a decade into a subfloor that never dries through summer takes the joists, then the bearer, then the stump, in that order, and the repair goes in the other order.

The enclosed under-house. A high-set Queenslander in Newtown or East Toowoomba that was battened in after the war and used as a laundry, a workshop or a rumpus room has had fifty years of less air under the floor than it was built for. The bearers along the enclosed walls, and over any concrete slab poured under the house later, are the ones to probe hardest. If the under-house is going to be fully enclosed as part of a raise, council's guidance is that it becomes a habitable room needing a 2.4 m ceiling, and the certifier applies the ventilation rules with it.

Verandah and sleep-out bearers. The post-war low-set homes from Harristown round to Rangeville often grew a sleep-out, a laundry or a front verandah on their own short stumps and low bearers, close to the ground, under a deck or a concrete apron that traps water. Those bearers are the first to go and the easiest to miss, because they are not under the main house where the inspector looks.

Hardwood that is still good. The original hardwood in a 1900s cottage in Newtown or a 1950s home in Wilsonton, where it has stayed dry, is as sound as the day it went in. Replacement is done to sound timber, not wholesale, which costs less and keeps the floor the house was built with. Under a listed heritage place or in a mapped character area none of this work is visible from outside; if the base cladding or battens have to change to get at the bearers, ask council's planning team first.

The termite rule. The building code requires a termite management notice in the meter box, QBCC recommends a yearly inspection, and the NCC Queensland variation sets a 50-year design life for termite management in new work. A bearer replacement is a repair rather than new work, but the same logic applies: caps on the stumps, clearance under the floor, and an inspection schedule that a landlord actually keeps.

Managing it as a landlord or a buyer

Bearer and joist work is the part of a restump most likely to change the price after the owner has agreed it, because it is only found once the battens are off. The practical answer is a quote that sets the rate per metre of bearer and per joist in advance, a builder who photographs each soft section before cutting it and sends the photograph with the length, and an agreed limit above which the builder rings before going further. That turns a surprise into a sum. For a house being bought or sold, ask for the before and after photographs to go with the final certificate, because the next building inspector will want to see what was replaced and where, and council's building plan search only holds plans lodged since 1975.