S-01-06-01

Foundation Lining - Preparation

Ensure the soil in the trenches really is flat and clean and ready for the linings.

Check Form-a-drain height

It's worth checking again that the outer Form-a-drain is at the right height. If any slight raising is necessary then use a prying bar and adjust the shims underneath. At this stage of the game we are looking for exact levelness at the exact right height.

Remove wooden spacer lengths incrementally

Using 4'5" lengths of 2x4 are an added precaution against inward movement of the Form-a-drain and are fairly easy to remove as you work your way round doing the lining.

Spacer Wood In Footings As Needed

Check footing trench soil

Check the soil below the footings is nice and smooth. Remove any high spots and protruding rocks. Fill with compacted non-organic soil any low spots caused by removed rocks.

Footing Soil Trench Smooth

Sweep the trenches clean

Clean up the job site. Get rid of rubbish and put away your tools. The chances are that some of the crushed rock has fallen into the trenches. Before putting down the membranes, make sure the soil in the trenches is free from sharp rocks and other debris.

Foundation design

Throughout the process of adding the different layers you will want to constantly refer to the Foundation design drawing. (Click on image to see and download high resolution version)

Here is the drawing version for the internal concrete walls...

Don't bother to treat ground for termites

You can buy termite treatment from your local home center in the gardening department. If you use it you would do it just before putting the polyethylene sheets on top so that evaporation is avoided and rain does not wash it away.

Note that termite soil treatment only lasts for about a year, and the house is designed to last for 500 years, so it really is of very little use to treat the soil for termites. If you are in a high termite area then you might consider once a year blocking up the under slab drainage pipe at the house exit using an inflatable bladder and pouring termite treatment down the cleanout pipes and radon vent pipes.

My main defense against termites burrowing through the polystyrene will be the 6 mil polyethylene sheets and other membrane layers. Also there is no wood used in the house structure so there is little to attract termites. I decided not to bother with termite poison. If I ever change my opinion then I will retrofit it using the drainage pipes under the building.