While most wool insulation uses waste wool that isn’t good enough for other uses (clothing, upholstery, home goods…) Havelock uses the full wool coat from Romney sheep raised in New Zealand. The sheep are sheered twice yearly and the wool is shipped to the Reno, Nevada facility where it is processed into two types of insulation: batts and loose-fill.
Sheep’s wool has some unique properties that make it great building insulation:
- The kinks in the wool create pockets that help it trap air for excellent insulation
- Its resiliency means that even when wet, its insulation properties aren’t affected. In fact, it can withstand 65% humidity without being negatively affected and will release excess moisture when the air is dry.
- It’s pest resistant due to a mild boric acid treatment (8% by weight)
- It’s mould and mildew resistant
- It naturally binds with formaldehyde, toluene, Nitrogen oxides and sulfur dioxide, taking these harmful substances out of the air, improving indoor air quality
- Its fire rating is Class A under the ASTM E84 standard testing methods for surface burning of building materials (This is a US rating. Wool does not have a fire rating in the Canadian National Building Code because it hasn’t been tested and the NBC only recognizes Canadian testing)
- It has excellent acoustic dampening properties
- Its R-value is 4.3 per inch
Embodied carbon: Wool sequesters carbon, similarly to wood and cotton products. In fact the wool industry touts that as a whole, it sequesters over 500,000T of carbon annually. Therefore wool is a carbon sink. The methane produced by the sheep is accounted for in the lifecycle analysis of lamb’s meat, since, generally, sheep are raised for their meat.
Expected lifespan: Havelock wool insulation will last as long as the structure it’s in. At end of life it is completely biodegradable.
Warranty: There is a 50 year warranty on the insulation, providing it is installed properly.
Canadian challenge: As with all wool insulation, it’s important to find an engineer or architect willing to sign off on using wool insulation. Despite its benefits, it is not recognized in the Canadian or any provincial building code at this time. Without an engineer’s approval, it might be difficult to find a willing insurer. There is no problem using wool insulation in the US. You can read more about wool insulation in general in this post.
Havelock Wool Insulation Products:
R7 – 2.0″ 125 square feet per bag
R 13 – 3.5″ 90 square feet per bag
R 20 – 5.5″ 60 square feet per bag
Approximate cost: C$189 per bag (prices are approximate and will vary by dealer and time).
Loose fill insulation
Coverage: There is a chart on this page that shows the different R-values attainable for 1000 square feet and the number of bags of insulation required. In a nutshell:
R-7: 6 bags of insulation, 1.5″ depth
R-30 26 bags of insulation 7″ depth
R-60 53 bags of insulation 14″ depth
Cost/25 lb bag (approximately): C$189
(Price will vary by dealer and time, please check with dealer for exact cost).
Within Canada, Havelock insulation can be ordered through three dealers: