We all know that good house insulation isn’t only essential for the planet, but it lightens the load on the pocket too. It’s a ‘buy well, buy once’ situation. From top to bottom, attics, ceilings, internal walls, ground floors and external walls, and for thermal and acoustic insulation, wool insulation is the natural choice. Breathable, safe, sustainable, fire safe, biodegradable. But how exactly does wool live up to these promises?
7 wool insulation benefits
The loft at Higher Hill Farm is prone to dampness, much like most attics in the country (and especially down in Cornwall, which can be, ‘moisture-rich’ at times!). Sheep’s wool and therefore wool insulation is a humidity buffer. It can absorb an astonishing 33% of its weight in water vapour, and lock this into its core, releasing it later when the air contains less moisture. This protects the structural timber, preventing it from sucking up the water and rotting. It also helps provide a dry environment for all the treasures you have stashed away in the loft.
In 2007, soon after we launched The Wool Company, we took advice from Martin Penk on the conversion of barns at Higher Hill to create our offices. Martin, founding partner of multiple-award winning sustainable architect firm Arco2 and director of EcoFab, is a passionate exponent of sustainable building and he showed us how to insulate the walls and ceiling with sheep’s wool waste, which we were able to source from nearby Devonia Products, Britain’s oldest sheepskin tannery. It was cheap, required no building skills, was non-toxic and entirely sustainable - a perfect fit for a husband and wife team with small children as labourers!
The natural twists and turns in the helical coil (the smallest part) of the dense wool fibre disrupt sound waves. Ecofab, Arco2 and other forward thinking organisations use sheep’s wool in schools and offices to ensure the whoops and shouts from next door don’t disrupt the worker bees. It’s far more effective than mineral wool insulation at preventing sound leakage.
Itch no more
There’s little worse than scrabbling around in the attic and emerging, dusty and seriously itchy from glass wool and rock wool fibres that man-made insulation is created from. These fibres can even damage your lungs and eyes. Despite this, most DIYers would tackle insulating their own roofs. We recommend they opt for soft, bouncy and harmless wool insulation. It’s just like laying a thick woolly blanket down in between the joists.
No, we’re not talking about the hairstyle lusted after by every 1980s teenager - we’re talking the natural crimp of wool fibres. This traps thousands of tiny air pockets, which in turn create what is known as a ‘thermal barrier’ that stops your home’s costly and artificially heated air escaping through the rafters. Equally, during hot summer weather, the wool stores heat during the day, releasing it later as the temperature cools. This heat-regulating property can’t be aped as effectively by manmade materials.
Insulating materials are measured by their thermal conductivity - or the ability for heat to pass from one side to the other. This is measured in watts per metre-Kelvin (W/mK), and the lower the number, the better. Sheep’s wool insulation has a thermal conductivity of 0.035-0.04 W/mK. Old fashioned mineral wool is measured at 0.044 W/mK.
Sheep’s wool is one of the only natural products that self-extinguishes. Yes, you read that right. Because the wool is naturally rich in nitrogen it will smoulder and singe instead of bursting into flames. Crazy as it sounds, it would have to reach more than 560 degrees Celsius before it actually burnt. This is why we have sold thousands of wool blankets for use as bedding on oil rigs.
Another reason to sleep easy at night.
You may already know that electric air purifiers aren’t necessarily all they are cracked up to be. But did you know that sheep’s wool does the job for you. Just as with wool carpets, sheep’s wool insulation absorbs and neutralises the nasties found in our homes, including nitrogen dioxide, sulphur dioxide and formaldehyde. How? Side chains of keratin amino acids in wool bond with formaldehyde, effectively sucking it out of the air. The keratin also suppresses mould and mildew.
100% natural, totally sustainable
Creating sheep’s wool insulation takes only 15% of the energy used to create mineral wool insulation. Not only is it an all-natural product, it is biodegradable at the end of its life. Result!
Our local farm shop, Village Greens, is a not-for-profit, run by lovely people to serve our local community on Bodmin Moor. They provide local and organic produce, fabulous cooked breakfasts and great company in our sometimes lonely bucolic idyll. We love what they do for our community, we love their gorgeous cakes and produce and want to share their weekly newsletter. In it Di provides beautiful and amusing insights into modern organic smallholding and farming life. Come and join us on Friday mornings if you can - bring a shopping bag too, but in the meantime, sit back, read on and enjoy...
The old dog decided that the best thing to do in the downpour yesterday was go for a long walk around the farm by himself. Given that he sometimes chooses to stay in bed on rainy days, this was an unusual decision on his part. He was perhaps taking an interest in pest control, since more traps have been set this week, to try and keep the population of rabbits, rats and moles at a reasonable level. Like most farmers, we love wildlife, but aim to keep a balance between a healthy diversity and an infestation. The mole activity in some fields has been getting out of hand, so the time has come to tackle these prolific diggers. It's a notoriously tricky job, with thier keen sense of smell, and extensive network of subterranean tunnels, the mole is an elusive creature.
All we can do is keep trying, to give both productivity and nature a fair chance.
The hot dry conditions are making it hard for vegetable growers to produce leafy greens. We have some lovely tenderstem brocolli this week, along with peppers, beetroot, cucumbers, tomatoes and courgettes. Doughnut peaches are still doing really well, their season seems vey long this year.
Well done to everyone who entered items in the show last week, the display of gardening skills and creative talent was outstanding. The trophy cabinets of local folk will be groaning under the weight of recently won silver ware.
See you there