Cut and fill is when builders cut into a hillside or slope, remove all the material from that area and then use it as fill. They then lay a concrete slab to build the house on which sits half on a filled area and half on an area below ground level. Builders say that putting a concrete slab on a cut and fill site is cheap. But at what cost to the homeowner?
Cutting and filling land carries risks – particularly when the land being filled is going to be used for house foundations. Whenever earth is moved the natural compaction is disturbed, and soil in this state is often described as ‘fluffed’ or ‘aerated’. In order for the earth to be safe enough for use in foundations it needs to be compacted to avoid settling. If it’s not properly compacted, settling earth can cause disastrous consequences including things like cracked foundations. Many houses built on cut and fill sites end up with a retaining wall or rock face right next to the home causing inadequate protection against flooding during heavy rain. Putting in drainage after completion of the home is very expensive. Often there is no access for machinery to the retaining wall or the back of the house. Excavation work has to be done by hand, sometimes requiring concrete or paving to be lifted and gardens to be disturbed. It is hard to know what parts of the block are soft or deeply filled. A geotech only drills 3 or 4 places on the site and these can vary in depth.
Install screw piles (screw piers) instead of concrete bored piles. Every pile is guaranteed to have the correct Safe Working load (SWL) specified in the engineers’ drawings.A gauge on the installation machinery calibrates the correct pressure and depth of each pile. A better solution may be don’t cut and fill. Use screw piers to create a level building foundation and use the the space created as valuable storage. Screw piers can be used as supports up to 2 metre above the ground level (in some cases even higher).
If our are considering a cut and fill solution to your next home build – thin again. Fill out the contact form instead on this website and let us do a comparative quote. You wll save time, money and future headaches.