OK then, you have done your site investigation, the outline planning is through and you are ready to start designing your foundations. Here’s what you need to know.
There are five main types of foundation common to low-rise buildings within which category domestic housing falls. What type of ground you are building on will determine what type of foundation you will need to use.
Foundations and how they work.
· Trench Fill
· Strip Foundation
· Wide Strip Foundation
· Raft Foundation
· Piled Foundation
One Important note. When you expose your trench you need to get building control, NHBC or an independent structural engineer to inspect your ground prior to pouring your foundations. Forgetting to do this could mean digging up your foundations as a worst case, especially if the ground is not suitable for the type of foundation you intend to pour.
Stay safe get your inspections done. micropile drilling
Trench fill refers to a technique used to fill up deep foundations trenches. What happens is this, you go to site and dig out for your foundations, but you end up about 1600 or perhaps even 2000mm below ground level. Well obviously you don’t want to fill all of that depth with good strong foundation concrete, so you order a weak concrete mix from your ready mix company and pour that into the trench until you reach the depth at which you propose to lay your foundation concrete.The trench fill needs to be only as strong as a good supporting soil, to provide a suitable base for the strip foundation.
A strip foundation is the simplest form of house foundation. It consists of a Gen 1 grade concrete laid to a width of 650m wide and usually to a depth of 350mm, with reinforced steel to either top or bottom of the foundation or in some cases both. It is preferable to have an engineer design the foundation for you, and provide you with dimensions prior to starting. Strip foundations are being replaced with wide strip foundations and are now relegated to supporting internal walls within the dwelling.
Wide Strip Foundations.
Wide strip foundations are similar to ordinary strip foundations except that they are wider. They are made wider in order to spread the load over more area of soil. The wide strip foundation is usually used in poorer bearing soil conditions.Wide strip foundations are usually 1 m wide x 450 mm deep, with reinforced steel to either top or bottom of the foundation or in some cases both, although an engineer can specify other dimensions depending on ground conditions and the load being imposed onto the foundations.