How To Get Your Building Started

Getting a Building off the Ground, or into it

To begin a house construction, the starting point is in the ground itself. Plans and approval given, site clearance can start.

It is easiest to employer a digger type machine to clear the site and expose the soil. The nature of the soil will determine the depth of foundations that have to be dug, and a survey drilling bore holes will help indicate it, and the local building inspector will have to be consulted.

If you have sizeable trees to clear, don’t cut them down to ground level, leave two or three feet standing, as this will make it easier for the digger to push out the roots.

Before breaking into the ground, check the site has accessibility to which ever parts you will need to get to, and that deliveries are not going to block you in or out.

The trenches should be marked out, and follow the plan for each trench to correspond with a supporting wall of the building.

The digger must proceed with a measure of caution, as un-charted obstacles may occur. Drainage pipes that have not been entered onto plans, old wells, or even old foundations can appear.

The trenches must be at least 1 metre deep, and be checked by the buildings inspector before proceeding. Different types of soil will determine the depth needed, and the type of foundation to use.

The more traditional type of foundations are strip foundations, which require a minimum or base layer of concrete in the bottom of the trench, a minimum of 250mm, and on this, build up with blockwork until ground level.

Where the ground is considered completely stable, trenchfill foundations are often used. The trench is filled with concrete to within two brick courses off ground level.

To reach stable ground, the digger may have to go deeper, the building inspector will advise, but when it gets to a depth of around 2.5 metres, it becomes both uneconomical or safe to proceed, and engineered foundations could be used

Pile-driving is primarily used where stable sub soil is too deep for conventional digging. In effect, a series of pile are drive down to stable levels, and then filled with concrete. This gives a series of columns to support the ground beams to build off.

Raft foundations are a heavy, solid block of concrete reinforced to resist the effect of ground movement, and an apron edge to prevent slide.