However there is an exception.
Required insulation in the attic.
Include insulation in the outer walls of the home.
Add insulation to attic.
Because the simplest and cheapest way to insulate an attic is to add material to the floor.
Existing 3 4 inches of insulation.
Recommended insulation levels for retrofitting existing wood framed buildings.
Plan to pull up the flooring and layer new insulation on top of the old.
Pa302 1 ceilings with attic spaces n1102 2 1 r402 2 1.
Nothing unusual about that.
A lot of builders and homeowners are going with spray foam insulation because of the airtightness benefits but then the questioner mentioned that the spray foam contractor had intentionally left big holes to the outside by not sealing the gable vents.
If your insulation doesn t measure up and you need more installation can be done as a weekend diy project or you can call a professional installer to handle the job.
The average recommended level is 14 inches of r49.
The average recommended level is 17 inches of r60.
You should consider attic or roof radiant barriers in hot climates reflective insulation and foundation insulation for new home construction.
Consider products that provide both insulation and structural support such as structural insulated panels sips and masonry products like insulating concrete forms.
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.
How much insulation in attic for zones 1 4.
The 2015 irc requires r 49 insulation for ceilings with attic spaces.
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.
But if the floor is covered in plywood you can t stuff enough insulation beneath it to do the job sufficiently not even in warm climates.
R 38 shall be deemed to satisfy the requirement for r 49 wherever the full height of uncompressed r 38 insulation extends over the wall top plate at the eaves.
In zone 1 the average minimum requirement for attic insulation is 9 inches of r30 fill.
Add loose fill insulation to your attic or foil faced batt insulation to your cathedral ceiling.
Earlier this year i got a question about a home that had spray foam insulation in the attic.
In temperate coastal areas such as zone 3 attic insulation of at least r30 up to a maximum of r60 is recommended.
For loose fill cellulose this translates to a total depth ranging from 8 inches.