Groundworks is the trade where Burton Latimer’s history matters most, and it is worth setting out properly rather than gesturing at.
Ironstone was quarried here from about 1872, north of the town first and then west and east, and the last pits closed in 1921 when the ore ran out. Those were shallow opencast workings, so the concern is not underground voids. It is what went back into the hole. Overburden replaced in the 1900s and 1910s was not placed to any modern engineering standard, and a century of consolidation does not make variable fill into uniform ground.
The practical consequence for a foundation is depth to bearing that varies across a single footprint. It is entirely possible to find undisturbed ground at a metre at one end of a trench and to still be in fill at two metres at the other, and a foundation designed to a single assumed depth will then be adequate in one place and not in another.
That is why a trial hole comes before the design here rather than after the quotation. It is the most useful hour anybody spends on a project in this town, and it turns the largest variable in the price into a known figure. Where the fill is deep, the honest answers include a deeper trench fill foundation or a different foundation type altogether, and we would rather price the right one than the cheap one.
Everything is inspected before it is covered. We book the inspections and we do not pour over an unseen trench. Our footings and excavation page explains our approach.