If you grew up on a farm, thoughts about hay are second nature. By “hay” I don’t necessarily mean “square grassy thingys you see in the field” but rather food for animals in various forms. Alfalfa, fescue and other grasses are baled in this way, and may be fed to farm stock during the winter or a drought to keep them going. Such animals have multiple stomachs and can digest the stuff. In fact, their digestive system depends on it’s presence. Quite a few bugs like it, too, and for good reason- it is often high in nutritional value. If you like bugs, build you’re house with hay, and they’ll figure out a way to take advantage of your generosity. If you don’t, then use some form of straw, which is the residue left from harvesting such crops as wheat, rice and some other grains. In the case of straw, all the nutritional value is found in the grain, and what’s left isn’t digestible. As you will readily agree, digestible houses might have a few drawbacks! 😉
Since “The Three Little Pigs” is the story everyone conjures up when told “we’re building a house out of straw”, it’s only appropriate to cover that subject right up front. Here are some facts to keep in mind:
- Yes- loose straw around a construction site is extremely dangerous, and there have been SB structures which burned down because a cigarette or torch got things started. The first rule, then, it not to leave straw lying around as you build!
- A SB (strawbale) wall, when properly built, is actually a stressed panel. This means it is two strong durable layers of some kind of plaster held together by the strawbales in the middle. This kind of panel is so strong that a house can be built using load bearing strawbale walls. For a variety of reasons we are using strawbale infill (and a post & beam frame) instead.
- I have read that in one fire rating test, a blowtorch was placed on one side of a SB wall, pointed at the plaster. As it ran for two hours, the thermometer placed on the other side of the wall rose exactly zero degrees. Would you put a torch on your wall for hours? 😮 Actually, we won’t either, but this test blows the fire safety myth right out of the water.
Hope this helps! In our next post, we’ll answer the “but what about bugs in the walls?” question…