The colour plaster for the drywall walls in this house combines white clay, finely chopped straw, and earth pigments to form a thick mixture that is applied with a metal trowel.
The plaster on these walls has been applied, troweled, and then hard troweled. Once fully dry, it will be ready for the finish plaster, or alis coat, that will add colour and further smooth the look of the wall.
A nicho (Spanish for “niche”) can be carved into a bale wall to add character as a spot for a statue or artwork. Straw bale building lends itself to creative shaping of the plaster walls, using the depth of the bales to advantage in crafting custom features.
When it comes time to plaster a straw bale house, have a party and invite all your friends, family, and neighbours! Many of the tasks can be learned quickly, and the more people that come, the more fun everyone has. Even the owners’ three year old son couldn’t resist slapping on some gloves and getting a little muddy.
In many straw bale homes, a truth window is a place on one of the walls where a cabinet or window reveals a section of the raw bale wall underneath the plaster to assure skeptics that yes indeed, this house is built of straw.
Plaster tests are done before plastering to decide on the right mixture of ingredients for the current application. The tests are allowed to fully dry and then are inspected for how well they continue to adhere to the bale wall and whether there are any issues with cracking.
After the walls have been stuffed and shaped, the clay slip is sprayed onto the walls with a stipple hopper attached to an air compressor. Clay slip is a mixture of bagged clay and water. This step saves time and labour over some more common plaster methods.
After the large gaps between the corners of the straw bales have been stuffing with dry straw, the walls need to be stuffed with light clay straw and shaped with a lancelot tool to create a relatively flat surface on which to apply the plaster.
Rather than laboriously tossing clay slip with straw by hand to make light clay straw for finishing the stuffing of the bale walls, we used this mixer to speed up the process. We could mix large batches of light clay straw in a short amount of time as well as maintain a consistent amount of clay and moisture on the straw.
Wooden I-beams are installed during the straw bale stacking process as anchor points for hanging cabinets or heavy artwork. This must be thought about at the planning stages, because straw bale walls covered in plaster are not strong enough to hold the weight of heavy objects.