Saturday, February 13, 2016

Roxul Vs. Fiberglass Vs. Foam Insulation

The upstairs bathrooms and ceilings in Christian's old farmhouse are being insulated with "Roxul" insulation bats made for either ceilings or walls, which have "R" values of 23 and 15; respectively. The largest room will accommodate two layers of R15 in the ceiling which will well insulate the main part of the oldest structure of the house. This insulation is made of lava-type stone making it fire and water/mold resistant while deadening sounds - which is all perfect for Christian's locations. Fiberglass is a bit less expensive, but the difference felt in a completed room is remarkable while the installation of "Roxul" dense bats (cut with a bread knife), is easy and less irritating.

The pink foam strips act as lifts on the roof walls to prevent any insulation from trapping moisture. These "Raft-R-Mate Attic Vent" boards as well as several types of "Roxul" insulation are sold at Home Depots.

The R value per inch for fiberglass insulation is 3.14, Roxul is 4.1, and closed cell foam would be around 5 for the rafter depth we have here. An install of 5" thick closed cell foam in the open ceilings of Christian's old farmhouse cost $3,000; however a partial house install does not work with this product. Spraying foam on old wooden beams, floor boards and electrical wiring seems wrong and too expensive for us besides. Single cell foam would be $2,000 for the same areas with the same issues and an R value of 3.7 per inch.


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