As noted in our last post we have had to do away with a full house craw space. Instead we have opted for a hybrid of sorts. We will digging a dropped crawlspace under the the bathroom to accommodate the composting toilet. This space will hold the systems for the Black, Grey and fresh water supply. All pumps and systems that can be damaged by water must be installed above the high water mark, which is only a couple of feet down from the ceiling. Our composting toilet has no electrical or mechanical systems that will be damaged by water, and our backup sump pump is submersible.
We have also moved the rain water tanks out of the crawlspace to a hole to be dug under the deck. This will eliminate the chance of hydraulic lifting that might happen in flood situations. Our choice of tanks has also changed and we will be installing only one Super Tank from Premier plastics that will be buried below grade close to spring ground water levels, which are rumoured to be 8’ below ground in that area.
Lots of discussion this week around Water Storage systems. We explored a number of options for storage but ultimately ended up deciding on installing Polyethylene tanks into basement.
Options considered were Made in BC, and NSF Food Grade
Pro: Good volume per sqf of floor, Moderately Priced, Easy to clean,
Con: Must be tethered to foundation so it doesn’t lift building (in flood)
Concrete tanks (built in place)
Pro: Highest volume per sqf, best integration into building
Con: Expensive, difficult to build proper lid, would require proper engineering, waterproof concrete additives expensive, High water table added a lot of engineering, material and labour costs,
Concrete Tanks (pre-formed)
Pro: Simple to install
Pro: Inexpensive, Flexible, no need for tethering (due to high water table), inexpensive shipping
Con: harder to clean, Least volume per sqf