When adding a second layer of insulation in the attic always add unfaced insulation.
Rp 30 insulation attic.
You need 20 in.
Here s what i mean.
30 grains of black powder will drive that lead ball just fine.
In general an attic s r value should be between r 30 and r 49.
Your joist cavities are completely filled lay unfaced insulation in long runs perpendicular to the joists.
Here s how to use 3 layers of 2 inch polyiso foam board to meet code and keep your ne.
Department of energy recommends an r 30 to r 60 for attics.
Sixty grains even faster.
The higher the r value the better the thermal performance of the insulation.
90 grains might be approaching the ma.
Of insulation to reach an r 60 in your attic.
Kraft faced insulation has a vapor retarder that helps to control moisture.
Both can be added to uninsulated attics or layered over existing material.
R value is a measure of insulation s ability to resist heat traveling through it.
Loose fill or batt the common term for blanket insulation.
786 429 60.
For diy attic insulation you ve got two choices.
Insulation level are specified by r value.
In particularly cold climates you might go up to r 60.
Better than spray foam thermal break and relatively consistent r 30.
Owens corning pink insulation is soft to the touch and easy to install.
Owens corning attic insulation.
Once you ve decided which type is best for you examine the material options and prices to home in on the right product.
Johns manville unfaced batts and rolls effectively control heat flow to the outside and unwanted noise inside.
The table below shows what levels of insulation are cost effective for different climates and locations in the home.
Whoa whoa david oswald you ve just entered the domain of the law of diminishing returns.