Its value is currently 0 18 w m 2 k therefore the thickness of the open cell pur foam layer e g.
How to measure for insulating an attic.
Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.
Measure up from the drywall to mark your desired blown in insulation level.
This calculator is to be used as an estimating tool only.
For loose fill read labels.
Measure your attic s square footage.
Purios e which should be covered with attic is at least 21 cm.
Click the button to calculate the amount of insulation in square feet and man hours wall and ceiling fiberglass insulation needed for this job.
Inspecting your attic insulation first things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation.
For batts or rolls calculate the number based on the width and length of the product you re using.
In general an attic s r value should be between r 30 and r 49.
If you re laying the foil down on top of existing attic insulation on the attic floor then you just need to know the square footage of the attic area you re covering.
For example if you attic floor area is 30 x 50 then you re measuring 1 500 sq ft.
Each bag lists the required depths for a range of r values and the number of bags needed to cover 1 000 square feet at those depths.
Your attic should have a certain amount of insulation in it and the recommended level of insulation for your attic is dependent on where you live.
Input length and width of area to be insulated.
You determine this by multiplying the length x width of the space.
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.
The thickness of the attic insulation depends on the value of heat transfer coefficient u.
Generally speaking without any preexisting insulation in place it takes 10 12 inches 25 4 30 5 cm of loose fill to achieve an r rating of about 38 40.
Find the rough surface area of the base of your attic and ask the seller how many pounds of fill will be required to fill that area to 11 inches 27 9 cm deep.
In particularly cold climates you might go up to r 60.