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Friday 26 November 2010

Foundations

This pair of Passive Houses will have a sub foundation insulation; A standard method used in Germany but one of the first times it has been used in the UK.
The topsoil is scrapped away and a shallow trench is dug for a small retaining wall.
Before the sub foundation insulation is placed a dwarf retaining wall is built

This is not load bearing but is purely to support the insulation 


600mm of Extruded polystyrene with a density of 45Kg/M3 and a thermal conductivity of 0.032W/(m.K) is placed around the perimeter of the wall.


The hardcore is then sand blinded to produce a flat level base ready to receive the insulation.

Slabs of insulation are then placed carefully over the expanse of the foundation
 
The foundation insulation is then increased in thickness laid over previous layers crossing the junctions of the preceding layer to improve the load bearing capacity. A total thickness of 300mm is finally placed
Finally an impervious membrane is laid over the polystyrene which acts as a gas barrier and protects the insulation from damage when the concrete is poured


3 comments:

  1. Hi Chris - looks like the start of a great blog. I'm looking forward to watching the build progress.

    The dwarf wall to restrain the insulation is an interesting approach. Why have you gone this route, rather than to use timber shuttering and then attache the insulation on the outside later, as in the AI PassivHaus?

    Your comment on 600mm of insulation around the perimeter seems misleading. At first, I thought it was the thickness of the insulation, but it is actually the height.

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  2. Thanks for the positive comments, simply this because we found it quicker and easier to build a block wall, this was built in a day. The blcok will also provide protection against damage of the polystyrene. Timber would decay within the ground if left in place and could cause problems, otherwsie it would mean removing the timber shutter and disposing of.

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  3. Hiii! your blog is so impressive. Thanks for sharing standard method with us!

    A passivhaus or passive house is low energy home constructed by The ECO Refurbishments in London with quality construction techniques and rigorous designs.

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