What’s the difference between restumping, reblocking and underpinning?

Restumping, reblocking, and underpinning have one thing in common – they are related to the foundations on which the structure of a house rests. The terms refer to the process of replacements and repair of wooden or concrete stumps that support the structure. Although the three processes deal with the foundations of the house, they are not the same.


These two terms can be interchanged while referring to the replacement of foundation stumps. The reason being that both processes have a similar approach. If the concrete or wooden stumps underneath a house start to crack, contractors replace the old stumps with new stumps. Restumping or reblocking involves placing jacks to support the floor as the worn out foundation is dug out and removed. Once the cracked stumps are removed from the base, new concrete stumps are inserted in its place. This process may cause minor damage to the floors and the walls of the house. Our contractors fix these damages after the new foundation has been laid below the house.


This process is used exclusively for homes in Melbourne that have walls of brick veneer and a foundation of concrete slabs. Over the years, the weather and ground elements cause the slabs to crack in certain places or sink in certain spots. When this happens, the brick veneer losses its tight alignment, leading to structural instability. The underpinning process uses jacks to prop up the cracked and slumped slabs, while a new coat of concrete is poured around the jacks. This stabilises the brick alignment and adds more stability to the structure.

The Difference

The major difference between the three processes is that while restumping or reblocking the foundation stumps are completely replaced, but in underpinning, the concrete slabs are not replaced, they are simply reinforced with new material.