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.