How to Finish Plaster Around Windows in a Straw Bale House

Straw bales provide high insulation value.

The straw bale house uses a combination of timber framing and straw bales to create an energy efficient home. The straw bales are typically covered with plaster or stucco to seal the materials inside of a permanent wall. Applying the plaster around the windows is not difficult but it does require concentration to prevent overlapping the lines. The finish will be squared or rounded depending on the user preference and it will require several hours to set in place.

Things You'll Need

• Razor blade
• Roofing felt
• Bailing wire
• Wire cutters
• Stucco netting
• Plaster mix
• Water
• 5 gallon bucket
• Trowel

Instructions

1. Use a razor blade to cut an outline of the window with roofing felt. Create the felt outline with a six inch diameter that will extend off each end of the window. Place the felt against the straw bales and bend several pieces of bailing wire into a "U" shape. Stick the wire through the felt and the straw to hold the felt outline in place.

2. Cut a window outline out of stucco netting. Use wire cutters to create the outline and size it to match the felt. The netting will allow the plaster to be controlled as its layered around the window. Bend several pieces of bailing wire into a "U" shape and use the wires to secure the netting to the straw bales.

3. Combine the plaster mix and water in a five gallon bucket. Base the mixture on the package instructions. The amount of water used will vary depending on the type of plaster. Use a wooden stick to mix the plaster until it is a thick substance.

4. Scoop the plaster on a trowel and begin covering the stucco netting. Start on the outside of the netting and slowly work into the window sill. Use the trowel to smooth out the stucco and cover all of the wiring. Work slowly once inside of the netting and the window sill.

5. Place the edge of the trowel against the top edge of the window seal. Draw a strait line with the edge from corner to corner until the square or rectangle is complete. This will create a straight line and a clean finish.

Tips & Warnings

• Use an inside-out weeping motion with the trowel to create rounded edges. This skill requires some practice and it creates a unique look.

• Work with the plaster as soon as it is mixed. Waiting will allow the plaster to dry and it will not stick to the stucco netting.

References

• Sustainable Sources: Straw Bale
• Building Awareness: Green Building Window Placement
• Stein, Amanda. Stein, Bill. Bainbridge, David. The Straw Bale House. Chelsea Green Publishing Company. 1994.