Sheep Wool Insulation
Sheep wool insulation is a natural, renewable product that offers unique moisture management capabilities not found in synthetic insulation materials. Wool fibers can absorb up to 35 percent of their weight in moisture without losing thermal performance, and they release that moisture as conditions change, effectively buffering indoor humidity levels. This natural hygric behavior makes wool particularly well-suited for older buildings and renovation projects where vapor barriers are impractical. Wool is naturally fire-resistant due to its high nitrogen and water content, self-extinguishing when removed from a flame. It also absorbs and breaks down indoor air pollutants including formaldehyde. The premium cost reflects the natural sourcing and processing requirements.
Sheep Wool Specifications
Best Applications for Sheep Wool
Sheep Wool is recommended for the following building components. Each application link shows the specific R-value requirements by climate zone and how Sheep Wool compares against other insulation options for that component.
Thickness Required by Climate Zone
The table below shows the thickness of Sheep Wool needed to achieve the DOE recommended R-value for each building component in every climate zone. Cells showing "N/R" indicate that insulation is not required for that component in that zone. Use this table to quickly determine how much Sheep Wool you need for your specific zone and application.
| Zone | Attic | Wall Cavity | Wall Cont. | Floor | Basement | Crawlspace | Cathedral | Garage |
|---|---|---|---|---|---|---|---|---|
| Zone 1 | 8.6" | 3.7" | N/R | 3.7" | N/R | N/R | 6.3" | 5.4" |
| Zone 2 | 10.9" | 3.7" | N/R | 3.7" | N/R | N/R | 6.3" | 5.4" |
| Zone 3 | 10.9" | 3.7" | N/R | 5.4" | 1.4" | 1.4" | 8.6" | 5.4" |
| Zone 4 | 14" | 3.7" | 1.4" | 7.1" | 2.9" | 2.9" | 10.9" | 8.6" |
| Zone 5 | 14" | 3.7" | 1.4" | 7.1" | 2.9" | 2.9" | 10.9" | 8.6" |
| Zone 6 | 17.1" | 3.7" | 2.9" | 7.1" | 4.3" | 2.9" | 14" | 10.9" |
| Zone 7 | 17.1" | 3.7" | 2.9" | 7.1" | 4.3" | 2.9" | 14" | 10.9" |
| Zone 8 | 17.1" | 3.7" | 4.3" | 7.1" | 5.4" | 2.9" | 14" | 10.9" |
Cost Estimates by Climate Zone (per 1,000 sq ft)
Material cost estimates for Sheep Wool at the DOE recommended R-value for each climate zone and component. These are material costs only and do not include labor. Professional installation typically adds 30-50% to the material cost shown below.
| Zone | Attic | Wall Cavity | Wall Cont. | Floor | Basement |
|---|---|---|---|---|---|
| Zone 1 | $10,500 | $4,550 | N/R | $4,550 | N/R |
| Zone 2 | $13,300 | $4,550 | N/R | $4,550 | N/R |
| Zone 3 | $13,300 | $4,550 | N/R | $6,650 | $1,750 |
| Zone 4 | $17,150 | $4,550 | $1,750 | $8,750 | $3,500 |
| Zone 5 | $17,150 | $4,550 | $1,750 | $8,750 | $3,500 |
| Zone 6 | $21,000 | $4,550 | $3,500 | $8,750 | $5,250 |
| Zone 7 | $21,000 | $4,550 | $3,500 | $8,750 | $5,250 |
| Zone 8 | $21,000 | $4,550 | $5,250 | $8,750 | $6,650 |
Advantages and Limitations
Every insulation type has trade-offs that affect its suitability for different applications. Understanding these trade-offs helps you select the right insulation for your specific project requirements, budget, and installation constraints.
Advantages of Sheep Wool
- Suitable for DIY installation, reducing labor costs
- Excellent moisture resistance for wet or below-grade applications
- Superior fire resistance provides additional safety margin
- Well-suited for: Wall Cavity, Attic
Limitations of Sheep Wool
Compare Other Insulation Types
Browse specifications and cost analysis for other insulation materials to find the best option for your project.