Concrete Masonry Units, also affectionately called “CMU,” provide those fortunate enough to be able to lay hands on them with an easy, fire-resistant, low maintenance, cheap way to throw a wall together in a hurry.  All that’s needed is a foundation, the aforementioned CMU, reinforcement, mortar, concrete to fill the voids in the blocks where necessary, and somebody with a strong back to put it all together.  Convince your somebody to stack these ingredients evenly in neat rows – and voila!  You have a wall.  You can even cover up CMU with something else if they look ugly.  So where’s the drawback?

According to the Portland Cement Association, “the standard concrete block is a rectangular 8X8X16-inch unit (200X200X400 mm) made mainly of portland cement, gravel, sand, and water. The concrete mixture may also contain ingredients such as air-entraining agents, coloring pigment, and water repellent” (Source: PCA).  While cement is in many ways an exquisite material, it is also energy intensive to produce.  It’s also subject to price volatility due to fluctuations in demand, although I read somewhere that right now it’s being consumed by humankind in larger quantities than water.*

One solution to the problem of too much cement in one’s concrete walls is to bulk the mixture up with a large quantity of dirt.  Rammed earth construction and adobe are two alternatives that use soil composites and recycled rock materials – often from the very site on which the construction occurs (local is good).  This construction technique produces absolutely gorgeous, thick, luscious walls with amazing striations running through them.  Of course, the look is a bit “unconventional” and this might make it tricky to finance the construction in say, a pseudo-Victorian duplex development.  The other problem with this type of construction is that not every Tom Dick or Harriet knows how to do it.

Integrity Blockhas attempted to take the convenient aspects of a unitized masonry construction system and combine them with the earth-friendly, dirt-filled characteristics of rammed earth construction.  Integrity Block’s building blocks are made out of a super-secret proprietary soil composite that contains pre-consumer recycled content (waste material from mining and quarrying operations). The manufacturing process consumes 40 percent less energy and emits 39 percent less carbon (Source: Edmonds).  While the goal is to cut cement out of the formula for the blocks at some future date, right now there is 40% less cement than in traditional CMU (Source: Schwartz).

So here are some reasons why Integrity Block has all the makings of awesomeness: the super-secret proprietary soil composite is formulated such that blocks come in earthy colors like brown or gray; the blocks come in standard sizes, and they meet typical CMU performance standards and established codes.  Anyone (by which I mean almost everyone) who can lay CMU will be able to work with Integrity Block.  I can practically smell the LEED credit.

As far as I can tell, Integrity Block distributes its product only in Northern California, in order to keep the old carbon footprint low, but they’re trying to expand production across the United States (Source: Edmonds).  Let me know if you’ve used this product and describe the experience, if you’re inclined.

The large quantity of soil that has crept into these blocks make assigning them to the Earth category something of a no-brainer.  I wonder how they would perform in a marine environment – I’m picturing a sea-side marsh in Georgia, for example.

Cited:

“Concrete Masonry Units.”  The Portland Cement Association.  Accessed 01/29/10. URL.

Edmonds, Molly.  “What’s so Special about Integrity Block?” HowStuffWorks.com.  Accessed 01/26/10.  URL.

Schwartz, Ariel.  “10 Green Startups to Watch” FastCompany.com 11/10/09. Accessed 01/26/10. URL.