The building inspector came today to inspect the trenches. He only stayed a few minutes, as he was happy with what he saw, and we were cleared to pour the foundations.
Making the most of the digger
With the digger already on site, we asked the contractors to remove more soil from the extension’s floor area. Even after taking up the block paving and sand, the ground was still about 30cm too high for us to prepare the floor slab.
By my calculations, they shifted around 24 tonnes of soil—a job we had planned to do by hand. It cost a little extra, but it was well worth it.
Concrete day
The concrete lorry arrived early in the afternoon. We chose a company that mixes the concrete on the back of the lorry as it’s needed, rather than delivering a fixed quantity mixed at the plant. That meant we could take the amount we needed without worrying about running short or dealing with an unwanted surplus.
Some of the team wheelbarrowed the concrete into the trenches while others tamped it down and checked the levels.
The rain made things messy. As the ground turned to mud and the wheelbarrows began getting stuck, we laid wooden boards to keep them moving. Despite that, the pour went smoothly, and we’re pleased to have the foundations in place.
We used 5.3 cubic metres of concrete.
Preparing for the next stage
Next comes the concrete blockwork for the footings, bringing us up to damp course and floor level. We also need to order 15 tonnes of hardcore for the floor slab base.
Our planned floor build-up, from the ground upwards, is:
- 150mm of compacted hardcore
- A layer of sand
- A damp-proof membrane
- 100mm of insulation
- A second damp-proof membrane
- 100mm of concrete
- A sand-and-cement screed to finish
There’s plenty still to do, but getting the foundations poured feels like a big step forward.