When I was in high school my parents renovated our 80 year old farmhouse. During the demolition of the old plaster walls we discovered that old catalogues had been stuffed in the walls for insulation. It is funny to think that here we are almost 100 years later and we have chosen to use a similar approach to insulate the walls of our house. Well, okay… you can’t read how much a wooden toboggan was in 1920, but the idea of using recycled paper as insulation has a very familiar feel.
There are lots of choices on the market when it comes to selection of insulating materials. The most common is still fiberglass insulation, due to it cost effectiveness and relative ease of installation. However, fiberglass is probably the least effective insulating material. Another common material is spray foam. This is very effective at reducing air infiltration, and is a good insulator, but is one of the most expensive forms of insulation.
After looking at the pros and cons of different types of insulation we settled on cellulose insulation. And here are a few reasons why –
- It is a good insulator, with an R-value of 3.7 – 3.8 /inch.
- It is denser than fiberglass – therefore it performs better.
- The cellulose insulation used was locally sourced (N.S.) and composed of 87% recycled paper.
- There is very little waste in its installation as excess is sucked up and reused.
- The energy required to manufacture cellulose is 10 times less than fiberglass insulation and 60 times less than foam insulation (and contains no petroleum products)
- The cost of 9” of wet-applied cellulose was approx. 60% of the cost of 3 ½” of 2lb spray foam.
Being completely honest, we also used spray foam insulation (where we felt it was the best solution). We tried to limit the use both from a cost perspective and from an environmental point of view.
Some Details on Cellulose:
There are two different types of cellulose insulation both of which were used in 58 Upper Hillsborough.
Type 1 is a loose fill. This type can be blown loosely to attics and other low-sloped spaces or it can be dense packed into cavities. This type of cellulose insulation is primarily paper mixed with a fire retardant. Due to the fact it settles (although less when dense packed in cavities), it is primarily suited to horizontal surfaces such as attics, overhangs, and flat roofs.
Type 2 cellulose is wet applied and it contains a small amount of adhesives. Although there are more additives due to the adhesives, they greatly reduce settling, which makes this type of cellulose more appropriate for walls or steeper sloped roofs. This type of cellulose is sprayed on to the wall/into the cavity until it overflows. The excess is shaved off and sucked up for later use.
Because our wall thickness is 9” we had to install the cellulose in two passes. The installer recommend applying the 1st pass approx. 4” thick, prior to the installation of wiring and plumbing. Given the time of year, this allowed us to insulate earlier (with a little temporary heat the interior was a comfortable place to work) and it allowed plenty of time for the cellulose to dry prior to applying the second pass. Once the wiring and plumbing was completed the second layer was applied. The video below shows the installation of this final layer, prior to the vapour barrier being applied.