It’s a word we hear all the time, but we don’t always understand what it means: underpinning. Nope, it’s not a wrestling move that caused an annoying knee injury that you’ve never fully recovered from. It’s actually a way of repair for building foundations. There are a few methods of underpinning. The method in which your remedial builder chooses to underpin your building depends on what the issue is and the extent of the issue. In this post, we’ll walk you through a few different underpinning methods and their applications.

Pit method
One of the oldest forms of underpinning is the mass concrete underpinning method, also known as the pit method. It’s centuries-old and it involves extending the pre-existing foundation until the stratum is stable. Underneath the existing foundation, the soil is dug out carefully using pins. Then, the excavation is filled with concrete. This method is suitable for shallow foundations, so talk to your remedial builder to find out more.

Pier and beam method
The pier and beam method is another common way of underpinning. Reinforced concrete beams are used to transfer the load to piers, which allow the concrete to be poured. This method came about when the pit method wasn’t proving effective on deeper foundations. The pier and beam method is more suitable for deep foundations and basement retention systems.

Mini piled underpinning
Mini piled underpinning is a method of underpinning that’s commonly used when loads from the foundation must be transferred to strata that is more than 2m in distance. This method may be used if your soil is variable in nature, if access is restricted or if there are environmental concerns. The piles used are typically 450mm diameter bored pier in the base of the underpin. They are also used where the soils are below par or where large trees are in close proximity and we need to get down below their zone of influence.

Screw Pile method of underpinning
This method also involves screw piles being installed in the base of the underpin as the name might suggest. For this method, your remedial builder will screw piles in the base of the underpin which supports the weak foundation. This method is usually applied when water clogging or clay-ey soil has caused settlement in the soil and where a bored pier wont hold up and collapses. The screw pile overcomes this problem.

Underpinning may seem like a big task at first, but when you place your trust in the hands of specialists like Techniblock, your underpinning job will seem easy. Sure, your building may look like it’s being completely turned inside out, but its structural integrity will be stronger than ever. Techniblock are Melbourne’s expert foundation construction company, putting their years of experience in foundation construction and repair into making your foundation as good as new. With the right work ethic, equipment and expertise, Techniblock will get your home or building back up to scratch.