Concrete Stumps & Steel Stumps — Stump Replacement in Melbourne's North

Reinforced concrete stumps

Concrete stumps are the most common choice for restumping in Melbourne. They are precast with steel reinforcing through the middle and come in standard lengths. Each one stands in a hole on a poured concrete footing, and the bearer is tied down to it with a galvanised strap or bolt.

Where concrete works well:

• Low to moderate crawl spaces, which describes most inter-war weatherboards in Brunswick, Coburg, Northcote and Thornbury.
• Sites where the ground is reasonably stable once footings are taken down to the level shown on the permit drawings.
• Owners who want a fit-and-forget stump that does not need adjustment.

The limitation is height adjustment. A concrete stump is set at a fixed height. If the ground moves later, the floor is brought back by changing packers between the stump and the bearer.

Galvanised steel stumps

Steel stumps are made from galvanised square or round section with a welded foot plate and, on adjustable types, a threaded head for fine height changes. The foot is bolted to, or set into, a concrete pad.

Where steel works well:

• Reactive clay sites across Reservoir, Fawkner, Thomastown, Lalor and Craigieburn, where some future movement is likely and easy adjustment is useful.
• Taller crawl spaces on sloping blocks around Ivanhoe, Heidelberg, Rosanna and Greensborough, where long stumps are needed and bracing matters.
• Houses where access is tight. A steel post weighs far less than a concrete one, so it is easier to get down a narrow side path or through a small access hatch.

Steel needs the right conditions. It should be kept clear of soil and standing water at the top, and it does best where subfloor ventilation is good. Where the ground stays damp, we will talk you through how the base and footing detail protects the steel.

Bracing, tie-downs and ant caps

A stump is only as good as its connections. Every new stump is tied to the bearer above with a galvanised strap, bolt or bracket, so the house cannot lift or slide off in a strong wind. Where stumps are taller than the limits in the building standards, diagonal bracing is fitted between them to stop the subfloor racking sideways. Ant caps go on top of each stump to force termites into the open where they can be seen during a pest inspection. None of this is visible once the job is done, which is exactly why it is worth asking about before you sign a quote.

Can you mix the two?

Yes, and it is common. A house may have concrete stumps under most of the floor and steel stumps in a tall section at the back where the block falls away. Both types can sit happily under the same bearer line if the heights and bracing are designed properly.

Partial restump or re-pack instead

Sometimes the answer is neither new concrete nor new steel throughout. If an earlier owner has already replaced most stumps and only some have failed, a partial restump of the bad ones, plus re-packing of the rest, can be the sensible option. We will not push a full set of new stumps where it is not needed.

Stump replacement on its own

Occasionally only a handful of stumps need replacing: under a bathroom where a slow leak has rotted them, or under a heavy fireplace hearth. Individual stump replacement is still building work, and the replacement stumps must be installed to the same standard as a full restump. We can scope single-stump or small-group replacements just as carefully as a full house.

Footings matter as much as the stump

Whatever goes on top, the footing underneath does the real work. Footing size and depth are set by the building surveyor, sometimes with input from an engineer, based on the soil classification and the load. On the basalt plains that often means digging through heavy clay, and in some streets the crew will hit floater rock or solid basalt. That can slow digging but gives a good bearing surface once reached.

What we recommend

There is no single best stump for every house. We look at:

• Crawl-space height and how many long stumps are needed.
• Soil type and drainage on your block.
• Access for carrying stumps and concrete in.
• How much movement the ground is likely to throw at the house in future.

Then we give you a recommendation and, if you want it, a price for both options so you can compare. Book a free inspection and we will look underneath before suggesting anything.