Wool/Levi Insulation


What it is:

I’ve sort of grouped a couple forms together because they are similar in nature and effectiveness.  Insulation made of sheep’s wool and recycled levies and textile fibers.  Both of these are most commonly found in strips of  comes in strips of different widths to fit between Advanced Framing, Standard Framing, or Metal Framing though they can also be found in loose form as well.  They can fit between 2×4 or 2×6 framing, obviously having a higher R-value if thicker.  The purpose of insulation is to keep hot and cool areas separate.  It is equally important in hot climates as it is in cold climates.  It is also a sound barrier keeping your home quiet and private.  Most insulation types do this by trapping air, these types of insulation are no exception, the fiberous material leaves plenty of air gaps which makes for an effective insulation. Like other types of insulation it does not work as well when compressed.

Sheep’s wool insulation is exactly what it sounds like, the wool from sheep formed together and treated with boron for protection from pests.  Recycled levi insulation is made up of thick fibers of material leftover from the textile industry, often including levi jeans giving it it’s usual blue color.  Levi insulation is most often treated with boron for pest protection and a saline solution for fire protection.


Both of these are typically installed between studs, usually after sheathing is up they generally do not have any backing to tack them in place as they are pretty hearty and will hold themselves in place well if applied snuggly.   These are each much less irritating to your skin and lungs while being installed so while the use of gloves and safety glasses are a good idea in most cases it’s not necessarily required for safe handling.


Wool and levi insulation have comparable, if not slightly better, R-values than standard fiberglass batt insulation and are very easy to DIY in batt form.  They are much healthier to handle and don’t typically have any ‘harsh’ chemicals added that could effect your indoor air quality later.  Both are very ‘substantial feeling’ when compressed and much more durable over time than standard fiberglass batt or blow-in insulation, holding their form better and staying in place.   Wool insulation has great water resistant qualities naturally and can get moist without affecting the effectiveness of the insulation.  Levi insulation is treated to be water resistant and can dry out if ventilated, returning to its original effectiveness.  Both types are fire resistant, Factoid – both types have been known to be used in correction facilities as sleeping pads because of their durability, lack of health risks, and ability to hold form while remaining ‘fairly indestructible’.


While slightly better than standard fiberglass batt insulation there is still a fairly limited R-Value for thickness (space required) compared to other insulation types.  You can get about an R-3 to an R-4 per inch of wool or levi insulation.  These insulations typically cost a bit more than fiberglass, often 3-4 times the cost.  They are friendly on the environment, wool is a renewable resource and reclaiming scrap textiles diverts it from the waste stream.  Both are not heavily processed and therefore much more sustainably manufactured than alternative types of insulation.

Tiny House Specific and Regional Considerations:

Often times when dealing with tiny houses space is a premium and most want more interior space, in order to get energy codes suggested R-Value with either levi or wool insulation alone you would need to increase your walls to 2×6 construction.  You are of course not required to follow energy codes for tiny homes but ‘code’ is typically the minimum level suggested for energy savings and comfort.  This all varies quite a bit by location but if you experience either high temperatures or very low temperatures you will notice a big impact from quality insulation and R-values.

For information on other types of insulation please click here.

This is a collaborative site, if you have something to add/correct leave a comment!  If you have some words of wisdom on any of the methods mentioned feel free to share in the comments!

For a list of definitions please visit the definitions page

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About Macy Miller

Macy Miller is a Rocky Mountain native and the creator of MiniMotives.com. As a LEED accredited architectural designer she is a passionate promoter of good design, healthy living, and the tiny lifestyle. In 2011 she started construction on her 196 s.f. tiny house where she has been living with her partner, James, daughter, Hazel, and dog, Denver since June 2013. She and her home have been featured on Yahoo News, Time Magazine, Dwell Magazine, NPR, HGTV’s Extreme Homes and many others!

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