Foundation experts often get asked about how deep piles need to be. We wish the answer was an easy one, but it’s not that simple. The thing about bored piers and screw piles is that their depth depends on a couple of different factors. In this post, we take a look at the different factors that influence how deep your piles need to be. We’ll also tell you who to speak with if you want the best foundation construction service in Melbourne!

Soil conditions

Soil conditions are one of the first things that are considered when figuring out how deep your foundation piles need to be. Some soils are more sturdy than others. Sand, clay and peat, for example, are far less stable than other types of soil, like gravel of bedrock. For these less sturdy soils, your piles need to be deeper in the ground than if you were building on gravel or bedrock.

What type of pile foundation are you using?

Another big factor is the type of pile foundation you’re intending to use on your development.

Driven piles

Driven piles are used to support tall structures, buildings, walls and bridges. They can be made from timber, concrete and steel and their ideal depth varies from material to material. Where steel driven piles can reach around the 30m depth mark, timber can only reach up to 12m deep.

Screw piles

Screw piles can reach depths of 36m and beyond making them very effective if you’re building on a reactive soil of some sort. Screw piles also cause less soil displacement because of their screwing technique, rather than drilling out the soil which is what happens with bored piers. Screw piles need to be at least 3m deep.

Bored piers

As said above, bored piers involve drilling out soil and filling it with concrete to create a very stable pile foundation. Bored piers can be drilled up to 40m deep, but this is only required for high buildings with heavy vertical loads; they usually only need to be at least 3m deep.

Mini piles

These piles are small, but they pack a punch! They have the ability to be driven up to 50m deep in the ground, but you’d rarely need to drive them this deep for a residential or light commercial building.

The minimum depth of piles tends to be around the 3-4m mark, but you should always leave this decision to the experts in foundation construction. Techniblock are Melbourne’s leading team in foundation construction and repairs, specialising in screw piles, bored piers, underpinning, basement construction and much more. Their technology allows them to reach depths of up to 26m, ensuring that your building has the sturdiest foundation possible. Get in touch with the team at Techniblock for a quote today.