[Greenbuilding] [BULK] Re: [BULK] concrete vs block vs ___foundation wall

[Bruce Donelson]

  Reuben Deumling  wrote:

  I like the idea of using concrete blocks, and not using mortar seems fine,
too. And I'm particularly fond of getting around building concrete forms. So
far so good. What I keep hearing conflicting opinions about is whether I
have to fill (all?) the voids with concrete and rebar, just some, or whether
I can or should put, say, some loose fill insulation into the voids? Any
thoughts?

  Also how does this concrete block approach compare with more advanced
systems like rastra or polysteel? I imagine it is cheaper, but are there
other differences worth keeping in mind?

  I would like to minimize the use of concrete (because of its energy
intensity) and I would like to imagine that the system for my 3' high
basement walls wouldn't cost too awfully much in materials.
   ******
  Around here the standard  crawlspace wall is 3 blocks high, or 2 feet. We
always grout all of the cells. We install vertical rebar every 4 feet, and a
continuous bond beam (horizontal rebar in blocks with a lowered web) near
the top. We do get earthquakes in Oregon, not frequently, but occasionally
strong. Strong winds from thunderstorms can also put stress on a foundation,
and soils that expand when wet can crack them, too.
  Monetarily, the most significant cost when grouting a foundation is
getting the concrete truck and pump out to the site. Buying an extra half
yard of mud is not the big deal. And regarding green building, durability is
a key factor. If your choice to skimp on the foundation leads to a
subsequent structural failure, your choice of bamboo flooring was largely
useless.
  If you can keep a building solidly attached to its foundation, and you can
keep the water out of it, it can last a good long time.

  Bruce Donelson
  A  Better Builder
  O'Brien Oregon