What is the difference between restumping and underpinning?

Restumping and underpinning are two different methods of foundation and footing repair. Restumping is the process of replacing the old or damaged stumps with new ones, while underpinning strengthens the foundation by adding support.

If you are not sure whether your house is built on stumps or a slab, you can contact a reblocking contractor to come and inspect the property. They will be able to tell you which type of foundation your house has and whether restumping or underpinning is necessary.  

What is restumping?

Restumping or Reblocking is a process of strengthening the foundation by replacing damaged stumps with new ones. This is common when the building is on piers and beam foundation, supported by stumps. 

Timber, Concrete, and Steel are the three different types of stumps available in the market to use as stumps.

If you still have questions about what is restumping, check our blog.


What is Underpinning?

The technique of reinforcing a building’s foundation is known as underpinning. Underpinning is the most common method when your footings are on slab or strip footings.

It is also used to add additional support to an existing foundation when new construction, like a new story, is added to a building. 

What are the different types of Underpinning

There are several different types of underpinning that can be used, depending on the specific problem that needs to be addressed. They are-


Piles are driven into the ground to provide additional support for the foundation. It is used when a building is being constructed on unstable soil.

Plate Loading

With this method, metal plates are placed under the foundation to reinforce.

Slab jacking

This method injects concrete under the foundation to raise it back to its original level. It is used to repair cracked or damaged foundations.

Soil stabilization

This method treats the soil around the foundation to stabilize it. This can be done by injecting chemicals into the soil or by compacting the soil with special equipment.

If you are unsure which type of underpinning is right for your project, you should consult with a structural engineer or contractor. They will be able to assess the problem and recommend the best solution.

Underpinning is a complex process that trained professionals should only perform.

Is underpinning the same as Restumping?

No, restumping and underpinning are not the same thing.. Restumping is the process of replacing older or damaged stumps and setting new stumps, whereas underpinning is a process of adding support to the foundation. 

You might be curious about can you restump a house yourself, please check out this blog for more information.

How do I know if my house is built on stumps?

If you walk around the side of your house and find that the floor is raised off the ground or suspended, your house is likely built on stumps. You can also visually inspect below your floor height to see stumps. Stumps are typically made of concrete but can also be made of timber/wood or steel.

How do I know if my house is built on a slab?

If you found access between the floor and the ground below, then the house is built on stumps. If there is no access, then it is built on slabs. 

Another way to find out is that if there is ducted floor heating or cooling, then the house is built on stumps.

If you need to be sure whether your house is built on stumps or a slab, you can contact a professional contractor to come and assess the problem. They will be able to recommend the best course of action.