Insulation for your home, you, and the environment
There is an important adage to keep in mind when building and insulating your home. “Good in, good out”. The better the inputs the better the air you breath, the smaller the impact on the environment and the more enjoyable the space for you and future generations.
What insulation value do I need?
Many factors will determine which type of insulation to choose, including your home’s construction but you always have to start with location. Location speaks to the geographical region your home is in. It is a map showing the general climate for the area you live and then builds a color coded map to give you a clear guide for what insulation thickness you need for each space. Find the color on the map that most closely matches where you live. Then find the area’s color on the corresponding R-Value chart. R stands for Resistance!
7 key criteria that we will use to evaluate the options and name a winner
We will be comparing a range of insulation types.
Rating scale for each judged criteria is on a 1-10 scale with 1 being low and 10 being the highest score.
Fiberglass
R - Value: 2.5 / Inch
Sound: 5 - Decent density of the product results in middle of the road sound dampening.
Moisture: 8 - Being an inert material, fiberglass insulation neither absorbs or holds water and will not support mold growth
Ecology: 2 - Fossil and rock based, fiberglass insulation has VOC’s in it. About 7 that all fall into the “complex names, that shouldn’t be used in products around people” category. The most present is formaldehyde which is an irritant that effects the eyes, nose, throat and lungs. Long term exposure to formaldehyde may cause cancer. There are companies producing formaldehyde free versions so if this is your choice. Seek those out.
Air: 3 - Initial off gassing of chemicals following new installation dissipates over time and if you want a complete detail here is what the EPA says. Let’s just say, those with asthma should steer clear of this product.
Installation: 7 - Roll out or staple in place.
Cost: $
Overall score: C-
Reason for score: Low rating based on the ecological and air quality concerns associated with this product. It would be lower if the cost was more expensive. Fiberglass insulation has improved its ecological footprint over the last 10 years but it is made from what it is made. If you can, get something ecologically friendly. But if this is your only option based on cost, search out the formaldehyde free fiberglass products.
Cellulose
R - Value: 3.4 / inch
Sound: 4 - Unless tightly packed the sound dampening quality of the product is minimal. Over time, the insulation settles creating gaps allowing for easier sound transmission.
Moisture: 3 - If cellulose absorbs moisture inside the wall, it can take a long time to dry out due to the closed nature of the wall cavity. Unfortunately, that moisture dramatically cuts R-value and may lead to the formation of mold and mildew.
Ecology: 4 - Cellulose insulation technically can come from any cellular plant source, such as corncobs or sisal. But commercial cellulose insulations are generally derived from wood, and more specifically from paper: recycled newspapers, cardboard, office paper, and other common waste paper products. For this reason, cellulose insulation is considered an eco-friendly home product. Additionally, it is comprised of up to 85 percent recycled materials. However, the remaining 15 percent, which includes the borate treatment, is less-than-green because it is a chemical treatment.
Air: 6 - The chemical used to treat the cellulose is borate which (to give the product great fire retardant) does off gas over time but it is minimal and doesn’t include an odor.
Installation: 7 - Blown in and faster than bat insulation.
Cost: $$
Overall score: B-
Reason for score:
A great option if you are not exposing your walls as cellulose can be inserted into wall cavities through a series of holes and settles well to fill tight and close gaps. That said, if it isn’t packed tightly enough over time as it settles it can create gaps at the tops of walls which diminishes the efficacy of the product. Overall, it works but it is a bit of a green washing product since the majority of the commercial and residential options are using wood based mediums even though non-tree based options are available and equally as effective. A great option for attics with open space.
Cotton (Denim)
R - Value: 3.3 / inch
Sound: 6 - Due to its density, this option outperforms Fiberglass
Moisture: 8 - To ensure the cotton denim is Class A fire rated it is treated with a borate-based flame retardant. Borate slows flames but also creates a water barrier stopping the denim from absorbing water thus preventing the growth of fungi and bacteria. A number of the manufacturers also include fungal inhibitors to further decrease unwanted side effects of moisture.
Ecology: 7 - The 3rd “R”, aka “recycle” comes into play to give denim insulation a green footprint and stopping a lot of your old jeans from hitting the landfill. Comprised of 100% natural fibers with the finished product being roughly 80% post consumer recycled content. Plus, it requires a relatively low energy input during manufacturing.
Air: 8 - Denim insulation is also non-toxic because it doesn’t contain chemical irritants, carcinogens or harmful airborne particles.
Installation: 8 - Formulated in all necessary sizes with built in break points it is easy to get in place. Just make sure you measure and then measure again.. before you order.
Cost: $$ (A little more than fiberglass)
Overall score: B+
Reason for score:
For most people this is hitting the new sweet spot for cost with a better ecological footprint. If you can get past fiberglass from a cost basis… This is the better option for just a little more. That said, you are still adding chemicals to manage moisture and fire, those components represent the 20% of the post consumer numbers above. That said, there is a low off gassing component to those chemicals. The ugly underbelly of this product is the initial cotton production. Cotton is a huge land and water resource crop per yield.
Image from elemental.green
Sheep’s wool
R - Value: 3.9 / inch
Sound: 8 - With a high density, the panel, slabs and rolls of wool have a great sound dampening ability, creating solitude wherever you are.
Moisture: 8 - Wool is naturally self regulating and can release up to 30% of moisture without compromising its insulation ability.
Ecology: 7 - Wool is ultimately carbon negative since it is naturally produced by grazing sheep. A relatively low energy input is needed to produce the end product but often times the products are coming from overseas.
Air: 9 - Wool is not a skin or lung irritant unless a preexisting allergy exists. It is fully breathable with allows it to purify and neutralize the air from harmful substances like those found in non VOC paints.
Installation: 7 - Relatively easy to stuff, roll or shake into place.
Cost: $$$ more expensive than synthetics. This calls into recognition to true cost of an unsubsidized product. Synthetics are often subsidized by governments through fossil fuel subsidies.
Overall score: B
Reason for score:
Hard to find in the US. This is primarily an EU product with its major roots in Ireland. So shipping it over can be difficult and fossil fuel intensive. If you can find it from a domestic source give it an honest review as the quality of air, sound, moisture and fire suppression are great.
Image by @vinceveras
Hemp panels
R - Value: 3.7 / inch
Sound: 8 - Excellent dampening do to the density of the hemp block
Moisture: 8 - Breathable and naturally mold resistant
Ecology: 10 - Hemp panels are bio based with 92% hemp fiber, has a very low carbon footprint and is naturally hypoallergenic.
Air: 9 - Breathability allows for natural scrubbing of air of toxic particles
Installation: 9 - Formulated to fit all different standard panel sizes and various depths. Measure well and enjoy a non-abrasive, non-toxic, easily cuttable installation experience.
Cost: $$
Overall score: A
Reason for score:
This product hits the triad of performance, installation and sustainability. If you can get past the slightly higher price point, this is the product for you 7 out of 7 days of the week.
Image from Hempitecture
Spray foam
R - Value: 6.5 / inch
Sound: 10 - By closing all gaps with foam you are getting the most complete sound dampening on the market.
Moisture: 10 - If you live in a mold prone, moisture rich environment this is the product for you.
Ecology: 7 - Spray foams come in two forms: Fossil fuel derived or green. If you choose green you are doing very well on the ecology scale.
Air: 8 - Open or closed cell option for the foam greatly differ in their ability to scrub the air of chemicals in the environment. As you would image, Open cell foam consists of open cell structures. Allowing for air to pass through and a softer more pliable foam. Closed cell foam creates a rigid and stable structure that doesn’t allow air or moisture to permeate.
Installation: 7 - DIY home kits are tricky, expensive but manageable if you do your homework on how to operate and spray. Otherwise, you are hiring a company to come in. In either instance the spray on is pretty easy if you have ever used a can a spray paint.
Cost: $$$$
Overall score: A-
Reason for score:
Phenomenal product that is a necessity for certain climates. It has an an R-value that doubles the competition but with that comes a more technical installation process that is inherently more expensive than some of the other options on the list.
Resource Link: Green Foam Option
R-values
And the winner is!
With all the above options the Good Ancestor team’s choice is the Hemp panel.
From an ecological standpoint, hemps natural ability to grow quickly and function as a carbon sink is a huge positive. This is due to the plants growth cycle being a carbon extraction process that deposits the carbon into the soil. Additionally, hemp can be grown as a cover crop, cycling between traditionally farmed commodities and hemp improves soil heath as it deposits the scrubbed carbon to regenerate depleted soil. Lastly, since hemp is a weed it takes less inputs to grow, little to no pesticides and very little water compared to traditional crops. It goes toe to toe with the bulk of the industry in R-values with it coming in on the top end of the average per inch of product. It is only slightly more expensive than the subsidized synthetics that are derived from fossil fuels.
Coupling that with solid sound, moisture, air and ease of installation and you can confidently say “Yes” too hemp.
We hope that this collection helps you to find the best ecological option for your future insulation needs!
