July 2009

A Floor – and Some Walls!

Our groundworks team are consummate professionals who take everything in their stride. So the trench which
had collapsed at the end of the last update was soon filled in, and by next morning the concrete retaining wall
was in place, ready for work to continue.

After levelling the ground, the next job is to lay a concrete 'blinding' layer, onto which everything
else is subsequently set. This is a special mortar which incorporates pulverised fly ash and granulated
blast furnace slag to reduce the amount of freshly quarried materials needed in the mix.

Tim uses a levelling tool to finish the surface of the concrete.....

...which, when set, is ready for the waterproofing membrane. This is a clever material incorporating a layer
of bentonite clay , which when it gets wet can find its way into tiny gaps and seal them automatically.
This means we should always have a dry basement.

With all of the waterproofing membrane in place, the painstaking job of installing the steel reinforcements got underway.

The weight of the entire house will be borne by the basement floor slab, so it needs to be very heavily reinforced.
Because of the heat-storing high thermal mass design, it will be at least twice as heavy as a conventional house.

All ready to pour the concrete for the basement floor slab the next day......

.......in torrential rain.

But our ground workers soldiered stoically on – pouring concrete.....

....levelling off.....

.....and finally power-floating to a perfect finish.

With the floor completed, the pace didn't slacken, and immediately the shuttering, which would be filled with
concrete to form the outer basement walls, began to go up.

Again waterproofing material was installed, plus the steel reinforcements to strengthen the concrete against the
pressure of the earth which will surround the basement.

Once more the concrete pump towered over the site.....

.....as the concrete was poured into the shuttering.
Fortunately, this time, the weather was good.

Foreman Lee LeBrun uses a vibrating 'poker' to ensure the mortar is fully settled, so that there are no gaps.

Meanwhile, the final levelling is done by hand.

A few days later, the shuttering is being removed from the now hardened concrete walls, and reassembled for
the second pour, which will complete the outer skin of the basement. Already we can clearly see the house
beginning to take shape, with the conservatory nearest to the camera, and the main body of the house,
looking deceptively small at this stage, behind.