How deep are ground screws installed?

Our ground screws vary in both length and diameter, with our “everyday” range starting at 76mm diameter and fixed lengths of 1050mm, 1250mm, 1550mm and 2050mm.

We also have 89mm and 114mm diameter screws in fixed lengths, and we have a range of extendable ground screws available in 76mm, 89mm and 114mm diameters, allowing installation to any depth required to reach a load-bearing ground.

To determine what length of ground screws are needed for a project, ground conditions and the load-bearing capacity need to be considered. Ground levels also need to be taken into account, where we will often use a variety of lengths in an installation to bring up ground that is uneven or sloping, ensuring each screw has an equal or greater load-bearing capacity than required.

The surrounding area may also come into consideration when selecting the right ground screw for your project. For example, if the site is subject to potential flooding or if there are trees with underlying roots nearby.

Finally, it is essential to install ground screw foundations to a depth that will not be subject to ground heave – the upward movement of the ground usually associated with the expansion and contraction of soils when wet and drying out.

When required, we can complete a pre-installation site survey, checking the ground conditions for suitability and ensuring the correct size of ground screws are specified for your project.

If you have any more questions about using ground screws for your next project, please contact your local installer, and they'll be happy to help.