Underpinning vs Reblocking: What’s the Difference? (And Which One Do You Actually Need?)
If you’re a homeowner in Geelong, Melbourne, or anywhere across regional Victoria, chances are you’ve come across the terms underpinning and reblocking — especially if you’ve noticed cracks in your walls, sloping floors, or doors that no longer close properly. But what do these terms actually mean? And more importantly: which one applies to your home?
At Fred R. Heimann Co. Pty. Ltd., we’ve spent decades repairing foundations the right way, and one of the most common questions we get is:
“Do I need an underpinner, or is this a job for a reblocker?”
Let’s clear that up.
what is underpinning?
Underpinning is a method of strengthening and stabilising the existing foundations of a home. It’s usually needed when part of a building has sunk due to soil movement, poor drainage, tree roots, or natural settling over time.
You might need underpinning if you notice:
Large or widening cracks in brickwork
Doors and windows that stick
Uneven floors or visible sloping
Gaps appearing between skirting boards and floors
An experienced underpinner will install new footings (called underpins) beneath the existing foundation to support and re-level the structure. At Fred R. Heimann Co., we’ve been helping families across Geelong, Melbourne, and surrounding areas with exactly this kind of work since 1983.
What is Reblocking (or Restumping)?
Reblocking (also called restumping) is a different process altogether. It involves replacing the stumps that support homes built on timber or concrete stumps, usually older weatherboard homes.
Signs you might need reblocking include:
Timber floors that bounce or sag
Loose or rotted stumps under the house
Difficulty opening doors or windows
General unevenness in the structure
A reblocker will go underneath your house, jack it up, and replace each stump — typically with new concrete stumps.
So… What’s the Difference?
Do You Need an Underpinner or a Reblocker?
While both underpinning and reblocking help to stabilise homes, they’re not interchangeable. Here’s a quick comparison:
| Underpinning | Reblocking | |
|---|---|---|
| Used for | Strengthening existing concrete footings | Replacing timber or concrete stumps |
| Applies to | Homes with concrete slab or strip footings | Homes on stumps (usually older weatherboards) |
| Trade | Underpinner / Foundation repair specialist | Reblocker / Restumping specialist |
| Cause | Soil movement, subsidence, tree roots | Rotten stumps, pest damage, old age |
If you’re not sure what’s going on under your house, don’t stress — you’re not alone. A lot of people mix up these two terms. The important thing is knowing what signs to look for, and getting someone experienced to take a look.
We don’t do reblocking, but we can usually tell straight away if a job falls into that category — and we’ll always let you know honestly. Our focus is strictly underpinning and foundation repair work, and we’re proud to say we’ve helped thousands of homeowners across Melbourne, Geelong, the western suburbs, and regional Victoria.
Why Choose Fred R. Heimann Co. Pty. Ltd.?
Over 40 years of experience in foundation repairs
Fully licensed, with HIA membership and a rock-solid reputation
Local knowledge of Geelong and Melbourne soil conditions
Old-school integrity with modern methods
Whether you’re looking for an underpinning expert, a second opinion, or just want to know what’s going on under your floors, we’re here to help.
Not Sure What You Need? Let’s Talk.
Feel free to reach out by filling our Contact Form and we’ll get back to you with our thoughts – no pressure, no sales pitch. Just straight answers from a company that’s been doing this for generations.