External scratch coat of earthen plaster goes on our straw bale house

exterior earth plaster scratch coat photo by eco logic design build moab

This week has seen the exterior of our house edging closer to completion.
The windows are in, and half of the exterior doors.

The second half of the week was dedicated to applying the earthen plaster scratch coat to our bales.
All cracks were stuffed with light straw clay, and wood members given a mesh to give the plaster something to cling to.
Then we applied a clay slip to the bales, this works it’s way into the bales and gives a little extra sticky for the clay in the plaster to grab hold of. We applied roughly an inch of earthen plaster, using this first coat to take out the bigger highs and lows formed by the bales being not quite even.


Earthen plaster mix for exterior scratch coat

1/4 inch screened, reject sand
straw, no bigger than 6 inches


Using drywall offcuts with earthen plaster

How to drywall sheet your walls for free? (and save drywall from the dump)

When commercial drywallers fit up a house, there are often offcuts from their work which don’t meet the next stud. So they are cut off, discarded and ultimately sent to the dump. These pieces are the height of a sheet (4ft).

We have been collecting those offcuts from commercial drywall jobs. They are happy to give them to us, as it’s saving them the fees to take them away. Continue reading

Earthen plaster on drywall

In the home we are building with community rebuilds, we have to use drywall to provide the sheer strength in the building.

Because it’s a manufactured product and can be reproduced to the same tolerance every time, it can be tested and rated for the sheer strength it provides. While an earthen plaster over lathe also provides sheer strength, no two earthen plasters are the same and as such you can’t be sure what it’s strength will be. (just one of the challenges that commercial natural building faces) Continue reading

Community Rebuilds Straw Bale house update

It’s been a hectic few weeks since the last house update, big changes have happened.
As well, we have been very busy with extra curricular activities that I will endeavor to update you this week!

The exterior plaster coat (scratched to allow the next layer of plaster, lime this time, to key into the first layer) dried up nicely, with only a few, acceptable, cracks.

We framed the interior walls, this really changed how we view and use the space. no longer is it one large room.

On the outside of the house, we applied a lime plaster. Kelly Ray Mathews came to share his expert knowledge, a large amount of sass and occasional epic laughs. We are using lime on the outside as it is a much tougher material than earth. It will stand up to more physical abuse while still staying moisture permeable. This is essential when using strawbales so that any trapped moisture in the bales will escape and not cause rot. We flew around the building in a record breaking single day!

Some of our walls are lathe and plaster, while others provide sheer strength to the building, so must be drywall. The lathe took a long time and nearly drove Dorte insane. The gaps between the lathe provide a space to push the mud into, this creates a tight fit and holds the plaster to the wall.

Drywall was screwed to the sheer walls and the ceiling. It was incredible that a wall the same size, took a few hours to lathe and 10 minutes to drywall. We want to use as little drywall as possible, it is a manufactured product made from gypsum that takes quite a lot of energy to produce. The lathe was beetle kill pine.
I thought the room would feel much smaller when we put the ceiling drywall up, but it wasn’t the case. I think because it’s white it bounces a lot of light around giving the feeling of a larger space.

The seams were taped, then mudded over to make the ceailing one whole piece. we spent a long time making sure there were no sharp joins that would be visible to the eye.

Next in was windows! Our house has eyes, or glasses now perhaps?
Our shiney new windows arrived and were installed in a day. We had a long discussion on the pros and cons of U value (insulation) verses E value (Emmitance – how much light comes through). When shopping for windows on a budget, we have to balance many options for the best possible result, having higher insulating windows usually wont let as much sunlight through. Meaning that while they won’t lose heat so quickly, they also don’t allow as much solar gain to be collected from the abundant sun.

Work continues on the house at a blistering pace, we have our schedule set for the next month and there isn’t much time to spare.
It’s an exciting month though, many changes to bring the nearly complete house into a liveable home!

Teaching natural building week @ Aprovecho

the crew!

I just finished teaching ‘Natural Building Week’ for this Spring’s ‘Sustainable Living Skills’ program @ Aprovecho.

I had such a blast, teaching light straw clay, earthen plaster and cob.

Thanks to everyone who came and learned, everyone was so into the building it was such a joy!

Light Straw Clay

We mixed up straw and clay slip, then tamped the mix into forms. This creates a strong insulative wall system, that once dry, can be plastered without any preparation.

Continue reading

The Playhouse

Project led by: Chris Foraker
Location: Aprovecho, Cottage Grove, OR
Date: August 2011 – July 2012

This project was the main build in Aprovecho’s ‘Sustainable Shelter Series’.
The playhouse is 150 square feet, small enough to avoid costly permits in Oregon. It features a variety of different natural building materials and techniques to both educate and be a model of what is possible.

I had the pleasure of working on this structure for the best part of a year. Spending time at Aprovecho is always a joy, being surrounded by so many varied but inspired people.

The structure, stove, most walls and base floor pour of this build were completed on the seven week Shelter Series. Subsequent plastering and finishing were completed over the fall & spring practicum and times in between where I was work trading.

The upstairs loft – You can see the split tone alised walls. Gonzo create the ultimate plaster mix for the final coat, leaving the smoothest earthen walls I have ever touched.

Continue reading