Those who have worked in the world of building science or high-performance construction for more than just a few days will be familiar with the phrase “it depends.” It can be frustrating when you hear it for the tenth or eleventh time in an hour, especially if you are just getting your bearings in the world of building science. It can feel like no one wants to answer your questions.

However, “It depends” is not meant to be evasive or dismissive. It is a polite way of saying that your question is not specific enough to produce a straightforward answer, and that you need to provide more information before a proper answer can be given.

Savick Founder Sam Kondratski regularly finds himself relying on the phrase when fielding questions about straw, as this is the insulating material of choice for the straw panels that Sam manufactures within his modest facility near Edmonton, Alberta. Some of these questions will come up in the below article but first let’s introduce Sam, Savick, and straw.

While Savick was born with these objectives in mind, Sam did not initially have a clear idea of how he would meet them. Eventually, he realized that every fall his home in Canada’s breadbasket, Alberta, was literally surrounded by tons upon tons of underutilized agricultural residue: straw.

As Sam succinctly put it: “Straw is cheap. We have a lot of it. Homes are expensive. They need insulation. Let’s figure out a way to get straw into those buildings.”

Straw at a Glance

Once the seeds from grain plants like barley, rice, and wheat are harvested, the leftover stalk is then cut at the base and left to dry in the sun. This is straw. Once the straw has had enough time to dry out, it is then baled, though some straw typically remains in the field to benefit the composition of the soil and return nutrients to the ecosystem as it decomposes. After being dried and baled, the straw can then be stored until it is time to be used.

Even though farmers do not harvest all the straw from their field and opt to rotate straw-producing plants with other crops, the amount of straw produced each year in North America is enormous. As a conservative estimate, Sam says that Canada produces enough straw to insulate more than 1 million homes each year, even though the nation only builds around 200,000. The ratio in the United States is similar.

Straw FAQs

Straw is a sturdy, safe, and effective insulating material that has the bonus of sequestering carbon. However, many people have reservations about using it in modern construction, as reflected in some of the more frequently asked questions that Sam encounters. We’ll explore those questions below.

Is Straw Going to Rot or Burn?

It depends.

Like wood or virtually any organic material, unprocessed straw that’s exposed to the elements will eventually rot. All biomaterials can also be combustible when exposed to a heat source and oxygen, and straw is no exception.

However, these materials are not just left out in the open. They are components of wall, roof, or foundation systems designed to withstand fire, prevent rot, and promote durability.  For Savick, the use of high-performance building methods allows them to create panels that stay dry (below 20% moisture content) and prevent the spread of fire. According to Appendix S of the IRC, straw can have a 1-2 hour fire rating depending on how the straw is protected on exposed surfaces.   

So, to answer the question, straw that has been dried, packed into a panel, and wrapped with high-performance membranes, such as SOLITEX MENTO Plus from 475, will not easily rot or burn. It will meet or even exceed any fire resistance requirements.

“Straw is pretty inert,” Sam says. “If you can protect it, it’s not going to be a problem.”

That said, not all straw panels are going to be built the same. Depending on a building’s climate, and more importantly the direction in which moisture is traveling through the wall assembly, modifications to the detailing may have to be made. For example, panels for a project in northern Alberta will be distinct from panels for a project in Seattle, as the latter will have to allow for far more drainage and drying.

Especially for high-performance projects where embodied carbon is a concern and the use of natural buildings materials is given a priority, straw panels can be an ideal and cost-effective solution. There’s a lot of straw around and there’s a growing demand for efficient and high-performance buildings.

“I think the two can be married together,” Sam says. “If you want to learn the how, we want to be a part of that conversation.”