R30 Vs R38 Attic Insulation
The material cost is minimal compared to the fixed costs of the contractor to do either or your time to pickup a blower and material.
R30 vs r38 attic insulation. Building new hame same answer. The results of the blower door test are not. The bottom line is that although you can certainly put r 40 insulation under your slab or r 80 insulation in your walls it may not be the smartest thing to do. Square feet of house or area to be insulated current and desired r value for insulation and type and cost of your energy.
Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. You ve got to do the calculations to find where your optimum is. Existing 3 4 inches of insulation. Attic existing 3 4 inches of insulation uninsulated floor uninsulated wood frame wall insulated wood frame wall 1 r30 to r49 r25 to r30 r13 2 r30 to r60 r25 to r38 r13 to r19 n a 3 r30 to r60 r25 to r38 r19 to r25 and add r5 insulative wall sheathing beneath the new siding 4 r38 to r60 r38 r25 to r30 add r5 insulated sheathing before.
The attic has about r30 insulation. That doesn t mean all those higher levels of insulation are cost effective though. Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces. I am considering whether or not its cost effective to insulate to r50 or r60 for the cost of about 1000 blown cellulose i have had a blower door test performed and will also perform some air leak sealing.
Add insulation to attic. The basement is finished and crawlspace insulated. That may sound odd but it s true. Installing additional insulation from r 30 to r 38 not so much.
An existing house with r 13 in the attic and installing r 30 v r38 is a no brainer.