Saturday, October 2, 2010


There are many facets to building a green home. We decided to start with two fundamentals: 1) Energy efficiency, as this has to be built in at the beginning and is hard to retrofit later; and 2) building the home ourselves.

Another facet of green building is using materials local to the site. Local materials not only use less energy for transporting them, they also tend to beautifully blend into the environment.
On our mountain, the one natural building material we have a lot of is granite cobble. If time (and consequently money) were no object, we might have decided to build our home entirely of that granite. While we couldn't manage an entire stone house like this one in Montana, we have decided to incorporate that stone where we can.

Three and a half years ago when we began this building project, moving dirt around was a primary occupation. We dug holes for our septic system, our black water tank, our footings, and so on. Every time we dug a hole, we sorted the cobble from the dirt using a homemade rock separator and a lot of serious muscle into large piles all over our property. I can't even tell you how many thousands of pounds of rock I've lifted and moved.

Today, all that very hard work of moving and stacking all those tons of rock started to take shape in a beautiful and satisfying way.
We are quite pleased so far with the work of Shannon from Girl Rock Utah, a stone-laying company based out of Ogden.

The rock looks as beautiful as I could have imagined and ties our home so specifically to its landscape.

A few notes on technique: The blue stuff is a fiberglass mesh that will help tie the mortar mix to the foam insulation behind. We chose fiberglass instead of a more traditional metal wire mesh (a.k.a. chicken wire) because we didn't want to introduce a thermal bridge from the rock to the house. The mortar skim coat over the mesh is there to keep the mesh in place while the rock it going up. The mortar mix is a pre-mix called "Spec-Mix" made locally and bagged by a company called Ashgrove. We did tests last fall with several varieties of mortar mix and liked how this one performed the best. We're using a thin mortar joint between rocks. This was a purely aesthetic decision. The rods sticking out of the house are non-thermal-conducting fiberglass form ties we specially sourced to build our concrete walls with. We kept a short length of fiberglass sticking out of the wall for the rock and mortar to grip around, thus keeping the rock connected to the foam and concrete of the rest of the wall. When asked about how to make a corner, Shannon says "I find a rock that looks like a corner and I place it." Perhaps masonry isn't quite as mysterious as the Masons tell us it is. :)

1 comment:

  1. The house I grew up in had these odd rock planters out front - a huge variety of all kinds of rocks. I only later learned that those rocks were collected by my parents on camping trips with my older siblings (I'm much younger). Not exactly local, but definitely special. I think your rocks are a wonderful addition!

    In our current house, I often wonder where the rocks in the fire place came from - I see the same type scattered through the neighborhood, sometimes on an exterior, and I'm sure there are similar fireplaces in other homes, too. Maybe some day that mystery will be solved! (I hope they're local, and because I know builders like to save money, maybe they are!)