Straw Insulation Properties

Disadvantages include susceptibility to rot difficulty of obtaining insurance coverage and high space requirements for the straw itself.

Straw insulation properties. Dried straw presents a fire hazard that can ignite easily if exposed to sparks or an open flame. The straw is the primary structural material in some straw bale homes it actually holds up the roof. Straw is made of cellulose which is a poor thermal conductor surrounding pockets of air also a fairly poor thermal conductor. Straw bale walls must be protected against driving rain by the coating and by deep overhanging eaves.

Some natural fibers including cotton sheep s wool straw and hemp are used as insulation materials. Insulation r values of various materials. Straw for this purpose often wheat straw is grown specially and harvested using a reaper binder. Straw bale walls are thick which give good insulation and thermal inertia that is a product of phase changes of residual moisture.

This adds aesthetic value to the home as thick wall are expensive to achieve with conventional construction. More commonly post and beam or. This article provides a table of insulation values and properties for various insulation materials useful in procedures to measure or calculate heat loss in a building defines thermal terms like btu and calorie provides measures of heat transmission in materials building insulation design data and heat loss in a building. One product uses recycled blue jean.

There are two options for insulating houses with straw. Advantages of straw bale construction over conventional building systems include the renewable nature of straw cost easy availability naturally fire retardant and high insulation value. 1 renewable it s a renewable resource which is typically composted or burned. Cotton insulation consists of 85 recycled cotton and 15 plastic fibers that have been treated with borate the same flame retardant and insect rodent repellent used in cellulose insulation.

We often just mix by hand. Straw clay insulation is only a moderately effective insulator. There are many mixing techniques for combining clay slip with straw. Thatching uses straw reed or similar materials to make a waterproof lightweight roof with good insulation properties.

Straw bale walls are at least eighteen inches thick. The density of the material results in an accepted value of r 1 6 per inch it is hard to beat the low cost of straw clay insulation. The sheer volume of the straw bale in combination with the insulative qualities of the material account for its excellent thermal resistance. The thicker the bale the better the r value.