Quick Answer
Sawdust and foam board are both viable insulation options for ice houses, but sawdust provides better performance and durability. Sawdust insulation can achieve an R-value of 3.5 to 4.5 per inch, whereas foam board typically has an R-value of 5 to 6 per inch. However, sawdust is more resistant to moisture and can withstand repeated freeze-thaw cycles.
Insulation Performance Comparison
When it comes to insulation, the key factor is R-value, which measures thermal resistance. Sawdust can be mixed with water to create a thick paste that can be applied to walls and ceilings. A 2-inch layer of sawdust insulation can achieve an R-value of 7 to 9, making it a cost-effective option. In contrast, foam board insulation is more expensive and often has a higher R-value, but its performance degrades over time due to moisture exposure.
Moisture Resistance and Durability
Sawdust insulation is highly resistant to moisture, which is essential for an ice house where water vapor can accumulate and compromise the structure. When sawdust gets wet, it absorbs the water and remains flexible, preventing the formation of ice crystals that can weaken the structure. Foam board, on the other hand, can absorb moisture and become brittle, leading to cracks and structural damage. To ensure optimal performance, mix sawdust with a natural binder like borax or cornstarch to create a more durable paste.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.