- One thick clay plaster layer with chopped straw for the base coat. This is for waterproofing and for adhesion to the straw bales.
- a middle, clay-lime plaster -- harder and more durable.
- top layer of slaked lime plaster -- hard and white. more moisture permeable. If moisture gets into the wall, we want it to wick away and evaporate into the air.
Wednesday, October 21, 2009
The exterior plaster has been going up quickly. We've had some freezing weather, so there's a kerosene heater hooked up to keep the plaster above freezing until it cures.
Here's the little I know about the plastering process... Eventually there will be 3 main layers, then 3 lime washes on the top.
The lime washes on top can be pigmented, or left pure white.
For this fall, we'll only get on the first clay/straw plaster on the exterior. This results in a weather-resistant shell to get us through the winter, and keep out rain and snow. It is thinner than usual, due to the cold temp's, but the thickness will be made up by the clay-lime middle layer in the spring.
Here's how things look as of Wednesday, October 21, 2009...
View Of South Wall
The first coat of plaster is up, and it's really starting to look like a house! View from SE.
Charlie and Ace clean up.
Nick smiles for the camera. There are lots of buckets and mixers that need to be cleaned and rinsed. Meanwhile Ben is chucking excess straw out the upper window.
There's a lot of loose straw, which creates a big mound on the west side of the house.
Ben peeks out the 2nd floor window.
Meanwhile, Steven bevels the interior of the large south-facing windows at 45 degrees.
Here you can see the beveled surface below, and the untrimmed square corners above.
An angle grinder with a Lancelot wheel (like a circular chain saw) is used to trim bales and bevel corners.
Here the crew relaxes after finishing the first exterior plaster coat, and poses for a photo -- the only time these folks weren't working to beat the coming cold weather! Straw bits have stuck to the wall in an interesting pattern.
...and Ace lands on the straw pile.
For now, the crew lets the plaster cure, while keeping it warm enough to avoid freezing. We're into a brief spell of warm weather, up into the 50's by day, and staying above freezing at night, which will help the curing process. The walls are now draped in plastic tarps, with openings on the corners for air circulation.
The windows are due to arrive tomorrow or the next day, and will be installed right away. Soon, we'll have a weather-tight shell, and we can proceed with insulating the roof and installing a wood stove to warm the interior for plaster and all sorts of finish work. Most of the crew will be working elsewhere for a few weeks while the plaster cures. They'll be back for the interior plaster after the windows and woodstove are installed.
Stay tuned -- much more to come.