Subfloor Repairs in Melbourne — Bearers, Joists & Floor Framing

What sits under your floor

A typical Melbourne timber-floored house has three layers of structure below the floorboards. The stumps carry the load down into the ground. Sitting across the stumps are the bearers, heavy timbers that span from stump to stump. On top of the bearers run the joists, smaller timbers spaced closely together that the floorboards are nailed to. If any of those three layers fails, the floor above suffers.

Many people assume a soft or sagging floor means the stumps have gone. Sometimes they have. Just as often the stumps are fine and the problem is in the bearers or joists above them.

Signs of subfloor framing problems

Framing problems tend to feel different from stump problems. Common signs include:

• A floor that bounces when you walk across it, especially in the middle of a room.
• Soft patches that give slightly underfoot, often near bathrooms, laundries and kitchens.
• Squeaks and creaks that have become noticeably worse.
• A dip between two points that are otherwise level, which can point to a sagging joist or bearer span.
• Visible rot, mould or crumbling timber when you look through the subfloor hatch.
• Old repairs such as loose offcuts, wedges or bricks jammed under framing.

What causes bearers and joists to fail

Moisture is the main culprit. Leaking shower bases, dripping pipes, blocked weep holes and gardens built up against the house all let water reach the subfloor. Timber that stays damp for long periods eventually rots, beginning at the points where it touches the stumps.

Poor ventilation makes moisture problems worse. Many older Melbourne homes have had vents blocked by later extensions, paths or decks, and the trapped air under the floor stays humid year-round. This is common in the inner north, where tight lots and later rear additions often leave little room for airflow.

Pests can also be involved. Borers attack certain timbers over time, and termites are active in many parts of Melbourne. Damage from either can weaken framing from the inside, so it is not always obvious from a quick look.

Undersized or poorly built framing shows up too, particularly in additions or older renovations where spans were stretched or timber was reused.

How we repair subfloor framing

The approach depends on what we find. Typical repairs include:

• Replacing sections of bearer that have rotted at the stump contact points or along their length.
• Sistering joists, which means fixing a new length of timber alongside a damaged or sagging one to restore its strength.
• Replacing joists outright where they are too far gone to strengthen.
• Adding support under long or undersized spans.
• Refixing loose connections and removing makeshift packing left by earlier repairs.
• Fitting damp-proof barriers between stump tops and bearers where appropriate.

Where we see evidence of termites, we recommend an inspection and any treatment by a licensed pest controller before new framing goes in, so the problem is not simply handed new timber.

Fixing the cause, not just the damage

New bearers and joists will fail the same way if the subfloor stays wet. During every repair we look for the source of the moisture and explain what we find. That might be a plumbing leak to be fixed, a vent that needs clearing, a downpipe that needs extending or garden soil that needs pulling back from the wall. Some of these are simple jobs owners can arrange themselves. Others need a plumber or drainer, and we will tell you which.

Subfloor repairs alongside restumping

Restumping is the best time to repair framing, because the house is already propped and the subfloor is open. Many restumps across Melbourne uncover at least some bearer damage, particularly in older weatherboards where the original timbers have been in contact with damp stumps for decades. Fixing them in the same job avoids paying twice for access and means the new stumps are carrying sound timber.

Subfloor repairs can also stand alone. If your stumps test sound but the floor is soft or bouncy, framing repairs may be all the house needs.

Getting a real figure

The cost of subfloor work depends on how much framing is damaged, the crawl-space height, access and whether the work is part of a larger restump. An on-site inspection gives a real figure based on what is actually under your floor.