Despite the fact that you won’t even see them once the house is finished, the foundations are a crucial part of any new build and getting them wrong could lead to disaster.
If you are building your own home for the first time, or extending, then you can never have too much information to hand, especially if you are planning to be quite hands on throughout the process.
Here are five important things you need to know about foundations.
1) Soil Surveys Make Sense
Your choice of foundation system will depend on the kind of ground you are working with, and unfortunately a cursory glance around your chosen plot will not give an accurate representation of what lurks beneath. This is where soil surveys are a very good idea.
Samples are taken from various spots around your plot, and give you a good indication of what you are working with (and assuming that the results reflect the make up of the whole plot), enabling your engineer to choose the right foundation system for the project.
2) Plans May Change When You Break Ground
Even with soil surveys, the plan for your foundations may change once you break ground.
Ground conditions can vary and it is only when you break ground that you can see if you have soft spots or bad ground that will require you to dig deeper than planned, or in more extreme circumstances, call on your structural engineer to redesign your foundations.
3) Building Foundations does not Always Involve Digging Trenches
When it comes to your foundations, there is no one-size-fits-all approach. Your site and soil type will dictate your foundation system, but it is worth knowing that not all foundation systems require the digging of trenches.
A raft foundation, for example, is a single reinforced concrete slab on which the building sits, allowing it to ‘float’ on or in the soil.
4) Don’t Forget the Spoil
It can be all too easy to focus on soil surveys, measuring out the site and choosing the right foundation system, but you also need to consider what you are going to do with the earth you excavate from the trenches.
You’ll either need to arrange for its removal from site, or you’ll need to find a suitable on-site location where you can store it (usually with a view to using it at a later date in the landscaping).
5) Correct Measurements are Crucial
Anyone who has undertaken any DIY projects has probably heard the phrase ‘measure twice, cut once’. In the case of foundations, this could not be more essential.
Foundations which have ‘wandered’ by a few mm can often be rectified in the first couple of courses by the bricklayers (this can be more difficult to achieve with timber frame). However, getting foundations professionally set out can be a very good idea.