How to Insulate With Straw

Straw Bales

• 1

  Stack straw bales around an exposed foundation to provide a temporary winter insulation. This is not a permanent application, as there is no good way to weatherproof the bales from the ground or elements and they will become damp over time.

• 2

  Stack straw bales along interior walls of a pole building, barn, shed or basement. The surface the bales rest on should be clean and dry and not exposed to weather or moisture. Roll out wire mesh along the bales and secure it and the bales together with metal stakes. If the conditions are dry, the bales can be left indefinitely as an insulating wall.

• 3

  Create an outer wall of straw bales by building a frame to support the straw bales off the ground. Stack the straw bales on the framing so the bales are not in contact with any moisture. Cover the bales with wire mesh and secure the mesh and bales with metal stakes. Apply plaster to the outer surface of the mesh covered bales to seal them from the elements. This type of straw wall will last indefinitely if moisture does not penetrate into the straw.

Loose Straw

• 4

  Coat loose straw with clay slip. Clay slip is a mix of clay and water that creates a thin, soupy mud-like substance. It is a fire resistant material. Lay the straw out on a flat area and spray the clay slip over it with a pump spray bottle, or drizzle it over by hand and rake it around to distribute the slip until all the clay is coated. Allow to dry.

• 5

  Fill empty spaces between studs and drywall with the straw the same way you would blown insulation. Tamp it down lightly to fill the voids as much as possible, but don't pack the straw too tightly.

• 6

  Cover the framing of unfinished walls with vapor lock type plastic sheeting used in insulation applications such as blown insulation. Fill the pockets with the clay-coated straw, being careful not to pack too tightly so the straw does not penetrate the plastic. Finish the walls as you normally would with drywall or whatever material will cover them.