The prescriptive r values for a new house in the new 2018 nc building code are as follows.
Insulation value for nc attic insulation.
Warmer climates only require an r 38 or higher or about 12 or more.
Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value.
Floors over unheated spaces need to be insulated to a minimum of r 19 in zones 3 and 4.
Almost all insulation products have to tell you their r value pipe and duct insulation are the only exceptions.
R 15 on exterior walls.
Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.
Existing 3 4 inches of 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.
According to home advisor insulating your attic can cost between 1700 to 2100.
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.
Walls need to be insulated to a minimum of r 20 if the insulation is between the studs or r 15 r 5 if the insulation is a combination of insulation between the studs and a continuous layer of exterior insulation in zones 3 or 4.
R 19 on floor system garage ceiling.
R value climate zone chart for wall attics and floors.
Contractor or insulation installer s fee.
Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces.
Recommended insulation levels for retrofitting existing wood framed buildings.
Type and material of your insulation.
Inspecting your attic insulation.
Wake county is 4a zone so walls floors ceilings and slab insulation values are unchanged from the 2012 code.
Duct wrap is covered so if you re looking at insulation with an r value of 38 from company a and insulation with an r value of 38 from company b you ll know the two products offer the same level of insulation.
Add insulation to attic.
R 38 for the ceiling attic.
The main factors that impact the cost are.
Many homes have no insulation at all because building codes didn t even require insulation prior to the mid 1970 s.
Square footage of your attic.