permaculture

[John Schinnerer <eco_living@yahoo.com>]

Aloha,

"life is what happens while we're making other plans..."  ;-)

Sounds like a good interim plan to get a starter tank inside.

>... followed in the future by a larger tank
> outside, either bermed in or insulated with straw bales or rastra.

Insulation alone won't give you the benefit of below-frostline earth
temperature, nor keep your water from freezing *eventually* (unless you
heat it at least some).  Get "enough" of the tank below ground and/or
raise the frost line around it by berming and it'll at least never
freeze, even if it doesn't get very warm either.
 
> The foundation for the building is pier footings. We will insultate
> with R10 for 18 inches below grade. 

You might want to go out with that insulation instead of down.  If
you're not already familar with frost-protected shallow foundations,
check out:

http://www.oikos.com/esb/43/foundations.html

and

http://www.cs.arizona.edu/people/jcropper/desguide.html

and if the foundations haven't already been done old-style deep piers,
check it out *quick* as it will probably save you time, money and
energy both short and long term.

>The plumber suggest putting the
> water pipes 5 feet below ground to avoid any freezing.

Put a strip of rigid foam insulation above them in their trenches and
you can probably just put them a foot or two down - same concept as the
FPSF, creating a little strip of earth under the insulation sheltered
from air and sky (radiation heat loss) temps.  

There was a thread about this on the ESSA list (list info and
searchable archives link at http://csf.colorado.edu/lists/essa/) quite
a while back and I think someone knew a smart builder or plumber etc.
who'd actually done this successfully numerous times in climates like
yours, deep winter ground freeze...

> We'd insulate
> down further than 18" for the perimeter but for the rock we've
> already hit. Some insulation is better than none, I figure.

Again, check the FPSF info; that insulation sideways, increasing the
size of the sheltered earth mass, might be better, or at least as good
and easier.  FPSF is still rare in the US, but those chilly Nordic
countries (ya, you betcha de ground she freeze...) have been using it
for decades, it's well proven to be a construction cost, material and
energy saver.


=====
John Schinnerer, MA
--------------------
- Eco-Living -
Cultural & Ecological Designing
Food - Shelter - Community
john@eco-living.net
http://eco-living.net

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