Choosing the right pool structure for your site

Soil, water table and access decide more about your pool than the shape you had in mind. Every site we survey tells us what it will and will not accept, and the drawings follow from that rather than the other way round.

Start with the soil. Black cotton soil moves with moisture and will crack a shell that was designed for firm ground. Rocky ground is stable but expensive to excavate, and it changes the programme more than the budget. Loose fill needs either compaction or a deeper foundation, and the only way to know which is a proper test.

The water table matters just as much. A high table pushes up against an empty pool, and an empty pool is a boat. Where the table is high we design for it, with a hydrostatic relief valve and a drainage layer, so the pool can be emptied for service without lifting.

Access is the constraint people forget. If a mixer cannot reach the excavation, concrete has to be barrowed, and that changes both the method and the cost. We would rather know on the first visit than on the first pour.

None of this is exotic. It is the ordinary work of building something heavy that holds water, on ground that was not chosen for the purpose. Get it right at the survey and the rest of the project is mostly craft.