Preparing the site for foundations

Abstract

The area of site to be used for building must first be cleared of all vegetation, with particular attention to tree roots and stumps. Such is the force behind living vegetation, that even grass can force its way through concrete. Although tree roots are dangerous under buildings and some trees such as poplars with wide spreading surface roots should not be allowed to grow within 5 m of foundations, as they dry out the soil and cause differential settlement and cracking; a plea is made for the retention of existing trees and shrubs on the plot whenever possible. Some builders will bulldoze the lot indiscriminately. Good quality turf can be stored for re-use later, and also the loam, or top spit as it is called, which must be removed, usually by mechanical means, to get to firm undisturbed soil. Existing drains must also be removed and diverted.