Aprovecho Sustainable Shelter Series 2011: Inside Insulation Course

Welcome to Aprovecho! This year is the first of an annual offering called the Sustainable Shelter Series. It's an amazing overview of natural construction techniques at a very beautiful place near Cottage Grove, Oregon. I'm here teaching the week-long insulation section of the series. This first picture is of the structure as I arrive to it, a beautiful hybrid timberframe ready for strawbales on the northwall, light clay straw on the east and west and chip-slip infill on the south. Talk about a lot going on in a little playhouse!

Bale infill begins the first day

Bales make great scaffolding too!

starting the mud mix for the light clay straw

this is a great screen system for a wheelbarrow, I want one of my own!

chinking the bales

ramming the straw clay

mixing table

making slip from the nearby pond's pure clay, what a resource!

more mixing!

the forms leap-frog up and before you know it, we've got solid walls!

reed mats for forms for the chip-slip sections

uh-oh, no workshop complete with out a mud fight!

one week and a dozen hard workers... and we've got some naturally insulated walls!

Chip-Slip Sauna

This project is one of the most refined natural buildings I have had the opportunity to work on.
It's a 10'x10' wood-fired sauna with chip-slip insulated walls and site soil earthen plasters.

The small building is framed with a quartered cedar log for the corner posts and stick-frame Larsen trusses in between.

Then we create the integral forms for the chip-slip with large reed matting.

We unroll the mats and secure them with staples as the walls get filled. These reeds mats will also work great as the plaster substrate.

The infill mix is half a bucket of site soil slip per two buckets of bark-free wood chips. I like to mix them on tarps and carry the tarps directly over to the wall cavities.

We wait several months for the wall to dry and then it's time to plaster! I add metal lathe and substrate details where ever its needed. The mix is screened site soil, mason's sand and chopped straw.

I also did several stained glass windows, including little sliders for ventilation.

and a six foot wide arched-top dormer window!

The finish coat of plaster is the same as the base coat except that the soil and straw has been screened to a finer level. We also add five coats of linseed oil. This darkens the color and protects the plaster from the elements.

oiling details

rear view of finished building

side view of sauna, with stone faced shower area

viola!