Hemp wool vs Sheep wool insulation | Everything you need to know

Hemp wool and sheep wool are considered to be the “greenest” or most sustainable insulation materials. In this video, we’re going to look at how they are made, …


  1. Even though you put up drywall, tape and mud, the wall is not completely sealed off and air tight. the wall will breath because the top and bottom are not sealed, plus, there are holes in the tops and bottoms of the stud plates where pipes and wires and even duct work passes through. Oh, and don't forget the area around wall sockets and switches.

  2. I found your video really interesting from the prospective of someone who works with wool. My objection is about the manufacturer and where they get the wool from which isn't great for their carbon footprint considering how much wool is produced in the USA or in other countries. As much as I love wool and am aware of the benefits of it, I am still not convinced that it is an ideal insulation product for homes in damp climates considering how much water it can suck up regardless of how environmentally friendly it is. I live in the UK and although it was used in really old houses, the houses breathed and heating was less efficient and these new products were not available then. I am not convinced that wool is the product for modern building practices. I think I would need more information why I should use wool over any of the other products with similar properties out there.

  3. LOL, Home depot and all the other building supply companies here in rural northern Georgia, USA refuse to sell hemp insulation because "Everything made form hemp is worthless and hemp farmers are scum". Oh ya, one dude also tried to say "hemp is illegal in Georgia" (it's not). Ya, we have a education problem here in GA.

  4. A very thorough analysis. One aspect of sheep wool that should be noted is that currently because of the explosion of synthetic fibres for clothing, the market for natural fibres like sheep wool has collapsed such that the price of fleece is often less than the handling cost so that it is either scrapped or given away free. Alternative uses of sheep wool like insulation should be encouraged as the environmental credentials are certainly worth having.
    I note that this video is a US production and uses 'R' values and fire ratings that are quite alien to most of Europe. In Europe and Scandinavia we use 'k' values that give the product dimensions as well i.e W/m.K for the heat transference that can then be combined with the thickness ('b' in metres) to give a resistance ('r) and then the total performance of a building element (the 'U' value in W/m^2 Kelvin) is the recipriical of the summation of all the b/k amounts. Therefore, it is possible to accurately determine the overall performance of the combined building elements. Having just a US derived 'R' number without units only appears to allow comparison between individual elements and not an assessment of the effectiveness in a system of construction.

  5. Just curious about weatherization/air sealing in basement rim joists? Energy-saving programs recommend spraying air gap form sealant and then adding batting. However, there is some concern about moisture getting caught between the rim joist and the batting which can cause rotting and mold. Do you have any suggestions for that?

  6. If we look at wall, ceiling and floor cavities as sealed units, protected mostly by sheetrock or a spray in coating, it seems as though hemp fiber is a viable insulation. If hemp gives off a pot odor, there could be a problem. I worked for a university for 20 years, developing efficient framing and insulating systems. There are many alternate insulation materials that have been proven fire safe. There's no substitute for testing and evaluation. If the Russian scientists are correct about the coming solar minimums we'll all be thankful for better structural insulation.

  7. Very interesting video. I am in general very interested in insulation materials, because of my work as construction engineer. And I am especially interested in environmental and indoor climate friendly materials. To my oppinion though, wood fiber insulation is the best insulation in the World. But the hemp wool insulation also sounds interesting. But I think you will find that wood fiber insulation works better against fire. It would be very very interesting to see this simple test: https://www.youtube.com/watch?v=nzTegn50-v4 expanded with hemp wool, sheep wool and woodfibre insulation (perhaps both as batts and as granule, as they can give slightly different results).

  8. Great job comparing every detail, I'd go for hemp wool for a house. Would probably have to double slab the ceilings for fire prevention. Makes me wonder why we can't recycle old woollen clothes…

  9. You mentioned you had a coughing fit after handling both kinds of insulation, are you sure its not just the hemp wool that caused irritation? Is the sheep wool anything other than simple sheep's wool? I'm fairly sure raw wool is safe to breathe around. Hemp wool seems really cool though, I wonder how it would be for like couch cushions or something given its elasticity

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