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 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.

Five of the upstairs rooms in this farmhouse have had their plaster ceilings removed and recessed lights as well as fans in the bathrooms have been installed. Two layers of Roxul 2" X 4" insulation bats have been installed in two ceilings, with single layers of 2" X 6" bats in the others.

The main bathroom above, had Roxul Safe & Sound also installed in the tub surround area which sound proofs the space from the adjoining guest bedroom.

Update: Below are the finished rooms...

South facing solarium...

Kitchen...