One of the most common forms of groundworks we handle for clients in and around the Guildford area is foundation installation. Quality foundations are essential for any building project, and without them a property would either gradually or rapidly sink into the ground, or collapse due to a lack of support. Not ideal. On this page, our groundwork contractors have provided some insight into the age old question: “but how far down should our foundations go?”
Should you be more interested in the reinforced basements we build, or the maintenance and repair work we tackle as Guildford and wider Surrey’s go-to drainage contractors, don’t feel obliged to read on! Instead, pick up the phone and call us.
There are a number of things that groundwork contractors consider when planning the depth of foundation installation.
The Nature of the Load – As a general rule, the heavier the load the deeper the foundation installation should go. To delve a little further, we can split foundations into two categories – shallow and deep. The shallow variety is used when loads are relatively low compared with the bearing capacity of the ground beneath. Deeper foundations are required when said ground cannot support the load safely. It’s our groundwork contractors job to transfer this load by providing foundation installation with a much higher bearing capacity.
Ground Conditions – On Guildford sites with stony ground, foundation installation can be fairly shallow, and either of the pad, strip, trench fill or raft variety. These are explained in detail on our foundation installation page. Clay sites require a slightly deeper foundation, in the 1m area (due to the points outlined in the moisture/water presence section).
If ground conditions are suboptimal, then we will keep digging to around a depth of 2.5m. At this point and beyond, our groundwork contractors will most likely shy away from shallow foundations. Instead, they’ll look to use piling or concrete rafts.
Moisture / Water Presence – It’s important to note the moisture presence within the soil/ground when approach all types of groundworks. Moisture can result in expansion/contraction which will effect a foundation installation, as well as reinforced basements installations for that matter. The rule of thumb is to dig down until the moisture content of the soil is considered stable.
Nearby Foliage – If there are trees close by where your foundation installation will sit, we will either need to dig a lot deeper or use steel to prevent tree roots from encroaching over time and causing damage to the foundations. As drainage contractors, and installers of reinforced basements, trees are truly our foil. They can get everywhere and compromise our hard work. So over the years, Lucas Groundworks Ltd has learned how to deal with them effectively, and ensure our Guildford clients won’t have to experience them trespassing in places they shouldn’t be!
Sewers & Drainage – Another angle to consider is how close underground drainage systems are. Foundation installation should run to at least to the depth of the sewer, if it sits within a 45-degree area of where the foundations will be. This is because of how load is spread and transferred. As drainage contractors as well as groundwork contractors, we’re uniquely qualified in this area, and will ensure no issues arise.
As you can see, when carrying out a foundation installation or building reinforced basements for a Guildford homeowner or company, or indeed tackling any other type of groundworks, there’s a lot that we need to think about. This is why it’s essential you choose the right team of groundwork contractors and drainage contractors for the job, and not opt for an inexperienced or general building services firm that might not get it right.