Some people have used bamboo in place of the rebar. The most common materials used to cover a straw bale wall are stucco or adobe. However, many materials can be used. Macatee, for example, covered his walls with cedar shingles so his home would resemble a barn. One concern when building with straw is compression of the straw caused by the unequal loads from the roof.
Careful planning can keep compression to a minimum.
The biggest concern of those new to straw is the fire hazard in bale house. The National Research Council of Canada reported that a plastered wall withstood temperatures of 1,850 degrees Fahrenheit for two hours before cracks developed. Actually, the biggest threat to a straw bale building is just the opposite. If moisture becomes trapped in the straw, it can cause the entire wall to decompose. To avoid this problem, John Swearingen, principal architect at Skillful Means, counsels would-be builders to avoid moisture barriers that are required on wood frame homes, but could trap moisture inside the straw walls.