Sheep wool insulation is something that we’re probably all aware of yet somehow we often dismiss it when it comes to buying insulation, either to retrofit our home or when building new.
I’m not sure why we do this? Perhaps we think it’s somehow inferior to the man made synthetic options out there. Or maybe we’re just so used to jumping in the car and buying off the shelf at the big superstores.
Whatever the reason you need to stop and start considering this wonder material. That’s right I did say wonder material.
Sheep's wool insulation offers a huge amount of benefits over synthetic insulation materials and almost no downsides.
Natural sheep wool insulation can absorb pollutants and regulate air quality within your home. Which is good news as we’re all currently obsessed with making our homes as airtight as as we can yet many of us don't add additional ventilation.
Limiting ventilation is not conducive to good indoor air quality especially as modern products such as carpets, MDF and flooring etc can give off volatile organic compounds (VOC’s) such as formaldehyde.
The fact that wool has the ability to permanently absorb formaldehyde and other VOC’s means it’s a great way to reduce their presence within your home.
During lab tests sheep wool insulation was able to remove formaldehyde at a concentration of 5 parts per million to zero within 20 minutes and it retained the Formaldehyde right up to 30ºC.
Sheep's wool is hygroscopic, so it can absorb around 25% of it’s own weight in moisture before its thermal efficiency drops. It will also release any moisture it absorbs back into the air when humidity levels drop. So it will help control humidity levels and help reduce condensation within you home.
If the surrounding air humidity levels are lower than the sheep’s wool insulation the wool will release moisture into the air. And if the surrounding humidity levels are greater than the wool it will absorb some of the humidity. This all means that your sheep wool insulation will not only keep you warm but it’ll also help regulate the humidity levels in your home and absorb VOC’s
An additional benefit of wool insulation is that when the surrounding environment is warmer than the wool and it releases moisture, it actually cools the wool slightly so it can actually help regulate internal temperatures when it’s warm outside.
The opposite of this means that when it’s cold outside in the winter and the wool absorbs moisture the wool actually generates additional heat and so can out perform many of the man made insulations.
In addition to helping heat and cool your home, wool insulation is also a good noise suppressant and performs better than many man made noise reduction materials.
When installed in a cold roof configuration, 300mm deep (i.e 100 mm between joists and 200mm over the joists, laid perpendicular to the first layer) you could expect to achieve a u-value of around 0.13W/m²K (This figure can vary with different sheep’s wool products).
As a comparison, the equivalent depth of mineral fibre would offer a u-value in the region of 0.15W/m²K.
If you’re currently looking to add insulation to your home and you want something that’s natural, itch free, can absorb and release water vapour and moisture as required, regulate temperature, provide sound proofing and absorb volatile organic compounds then sheep wool insulation is the answer.