Cathedral Ceiling Insulation R Value

Rafter vent with built in baffle 10 ctn.

Cathedral ceiling insulation r value. K1242 r 30 kraft faced batts 031979110407 30 10 25 d x 16 w x 48 l 58 66 attics and ceilings. Foam board insulation would be a more economical especially if you are supplying the labor see photo. High density sidewall batts are available in sizes to fit standard construction without loss of r value due to compression.

Add insulation to attic. Spray foam is a very expensive option however. Existing 3 4 inches of insulation.

Recommended insulation levels for retrofitting existing wood framed buildings. For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3. R value dimensions sq.

These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Where the design of the roof ceiling assembly does not allow sufficient space for the required insulation such as cathedral ceilings the minimum required insulation for such roof ceiling assemblies shall be r 30. Cathedral ceiling r value help if you re building in any kind of serious heating climate then an r 19 actually r 16 17 when framing is factored in with cold lines under the rafters is irresponsible.

High density cathedral ceiling batts allow an airspace between the insulation and roof deck for ventilation. Foil faced iso board can be cost effective insulation for finished attics and cathedral ceilings. Pa302 2 ceilings without attic spaces n1102 2 2 r402 2 2.

We ve heard about another product that has high r values without the bulk but haven t researched it yet. Owens corning r 21 kraft faced fiberglass insulation batt 15 in. Cathedral ceilings should achieve an r value of 30 or 38 to meet the energy efficiency requirements of the international energy conservation code and many state codes in a large portion of the united states.