Foundation (engineering)
Foundations are designed to have an adequate load capacity depending on the type of subsoil/rock supporting the foundation by a geotechnical engineer, and the footing itself may be designed structurally by a structural engineer. The primary design concerns are settlement and bearing capacity. When considering settlement, total settlement and differential settlement is normally considered. Differential settlement is when one part of a foundation settles more than another part. This can cause problems to the structure which the foundation is supporting. Expansive clay soils can also cause problems.
House-built engine
Such construction was also quicker to build on-site, as a pre-manufactured engine could be supplied by the engine maker in almost completed form. Skilled engine erectors were a rare resource, especially in remote mining areas, and the need to have them working on-site for long periods whilst a large house was constructed around the engine was often a cause of delays to an engine being completed. Even with adequate labour, masonry construction is a slower process than delivery of machinery alone. Where brick foundations were constructed, it was recommended that at least fifteen days were allowed before the weight of the engine was placed onto them.