New Old Insulation

A house kept warm with woolAlternative insulation sets precedent “This does not sound like a b-a-a-a-a-a-a-d idea,” - Fourth District Yolo County Supervisor Mariko YamadaBy JOSH FERNANDEZ/Democrat staff Writer
Daily DemocratHere’s a pop quiz:
In the stinging cold of winter, would you rather, a) put on a $30 jacket made of fiber glass; or b) wear a $40 sweater and mittens made from sheep’s wool?
Answer “a” would probably warm you up while saving you a few bucks, but answer “b” would be abundantly more comfortable and considerably less hazardous to your health.
So why, ask David and Anne Rawlins, wouldn’t you want the same for your home?
At least, that’s the rationale the couple used when they fit their in-progress Rumsey home with 100 percent sheep’s wool insulation, about 4,000 pounds of it.
Although common insulation choices, such as fiberglass, cellulose and rigid foam board are fairly inexpensive and effective, they pose some health risks: Cancer warnings are posted on most of the fiberglass insulation sold in the U.S.; fibers can become airborne and cause respiratory problems and problematic mold can build up through rain-soaked walls.
With the health risks posed by fiber glass and other types of insulation in mind, the Rawlins’, who have been building the 2,750-square-foot “dream house” on their farm in Rumsey for the past couple years, decided to use the most health-conscious, eco-friendly materials they could. After all, their youngest daughter has been diagonsed with breast cancer and is extremely cautious about the air she breathes, her father said.
Not to mention, the family just happened to have heaps of previously unusable sheep’s wool lying around.
“We had 3,000 pounds we haven’t been able to sell,” David said. “No one wanted to take our wool; too many stickers in it.”
The stickers - rough, prickly husks that usually cover seeds- are not conducive to processing wool for clothing, but they do no harm wool to be used as insulation, it turns out.
“And why in the world would we put fiberglass (in)?” David asked at a recent Yolo County Board of Supervisors meeting - after all, he said, sheep’s wool is a superior, water-resistant material and has been used throughout centuries for insulation.
As described by David, one of wool’s greatest benefits is that it insulates when wet, a claim that can’t be made about many other forms of insulation.
Wool is also naturally flame resistant, he said, and although it can be damaged by moths, it contains lanolin, a naturally occurring oil that protects it from these insects. To further safeguard wool insulation, some individuals add cedar shavings. Since the Rawlins’ home is constructed from cedar wood, it’s ideal for his alternative insulation, he said.
The Rawlins’ attended the supervisors meeting after Yolo County building inspectors said their wool-lined walls were not among the list of acceptable ways to insulate a house.
County Planning Director John Bencomo said building inspectors were caught off guard after going through the Rawlins’ home. Instead of the fiber glass they were expecting, the walls were lined with sheep’s wool.
“It was something different,” he said.
Had there been hay or rice straw instead of wool, there wouldn’t have been a problem, Bencomo said. In fact, he added, Yolo County was one of the first to broach the issue of using alternative means of insulation many years ago.
Fire protection, especially where the Rawlins family built their house, is a major concern for Yolo building inspectors.
“We wanted to make sure these people are protected,” Bencomo said. “This is located in the Capay Valley; there’s a much higher danger of fire, (and) volunteer fireman are sometimes 30 miles away.”
Bencomo said that for approval, the wool must go through a state testing process, as any other new product does, mostly to ensure that fire codes are met.
“It’s not just something the county can do unilaterally,” Bencomo said. “It does take time and money.”
Bencomo said he’s not, in any way, against using wool as insulation. However, it’s just not regulated right now, and those regulations would have to come from the state, he said.
“Likewise, in this area, there’s a lot of sheep, and wool on the market is not doing well,” he said. “It would be worthwhile to get this certified and get a patent.”
Rob Schlichting, spokesman for the California Energy Commission said his department is working with the Bureau of Home Furnishings and Thermal Insulation to see if wool makes the grade.
“(Wool) sounds strange, but they’re using shredded blue jeans (as insulation) now,” Schlichting said. “If we can get an R-value rating, we’ll put it in our list.”
The R-value is a scale that measures an insulation’s resistance to heat flow. The way it works is simple: The higher the R-value, the more the material insulates. Depending on several factors, including whether the house is being built new or a remodel, wool, for example, would have to have a minimum R-value of 13 in order to be considered an acceptable means of insulation, according to California Engergy Efficiency Standards.
Spokesman for the Bureau of Home Furnishings, Dale Chessey, said the department’s scientists are currently testing wool and working with companies with plans to introduce the product.
“It’s a new, upcoming thing,” Chessey said. “We’re working with Latitude Insulation out of New Zealand.”
Chessey said wool does indeed possess many of the qualities the Rawlins’ find attractive when it comes to insulating a building. Plus, California is always looking for new “greener” ways to insulate, he said. “We’re always open to new innovations,” he said. “It could be something of the future.”
As for making provisions for sheep’s wool as insulation and introducing it into mainstream home-building, Chessey said it’ll take a little time.
“It’s not hard, it’s just a matter of opening up dialog,” he said. “California is always on the forefront with introducing new standards.”
Meanwhile, Planning Director Bencomo said the Rawlins family can leave the wool in their walls, but in case the family decides to sell their home, they must let future buyers know their walls are lined with non-regulated insulation.
“We asked for some kind of disclosure statement on their deed or title … and that’s all we asked for,” Bencomo said. “Wool is used elsewhere, but I suspect it’s been certified or treated in some fashion.”
Indeed, wool is used for insulation overseas, mostly in the UK, Ireland, Scotland and New Zealand, however, David says it’s just too expensive to process and Americans, most likely, wouldn’t be willing to pay the high price.
“The expense of preparing it is about 20 to 30 dollars a pound,” David said. “No one could afford to do that.”
However, Rawlins, a former spa owner and inventor in his own rite, figured out a way to wash the wool to bring cost down with some scientific savvy and a tomato harvest bin.
“I devised a method of washing 200 pounds at a time,” he said. “That brings it down to about $2 a pound - a huge difference.”
Compared to about $6,000 to $7,000 for 2,000 square feet of fiber glass, wool insulation would probably be $1,000 on top of that, Rawlins said.
Price aside, Rawlins said he would simply feel more comfortable with a home insulated by wool as opposed to fiber glass.
“We’re wearing wool next to our skin and have been doing so for the last few thousand years,” he said.
Rawlins, who could be setting a precedent for future generations of homeowners in terms of what they use to insulate their homes, said he’s not interested in patenting his washing method.
“It’s nothing patent-able,” he said. “It’s really just a matter of physics.”
He would, however, be proud to have introduced to the county an eco-friendly insulation people can use in place of the traditional methods. “Yolo goes green,” he said. “I like that.” - Reach Josh Fernandez at 406-6233 or via e-mail at

Thanks Roy,
It was an interesting read.

Not sure what IAQ has to do with breast cancer. I there a medial link I don’t know about?

Believe it or not, I know people like that. Bales of wool that just never made it to market.

Fortunately the new OBC with its objective based format is more accommodating for situations like this.

I hear the hemp activists now - " :cool: ya officer dude, the 4,000 pounds of mary jane in my attic is… uh…insulation" :shock: