Solid core wood entry doors have some insulating properties naturally inherent in wood.
Insulated entry doors r value.
In the chart above you will notice that there are two vastly different r values provided for insulated metal doors with polyurethane insulation.
Many of these doors are remarkably like real wood and may have a thick polyurethane or other foam core a feature that boosts their insulating value.
Rochester patina 1 2 lite unfinished smooth left hand fiberglass prehung front door with sidelites model 873190 3a4 139.
The r values of most steel and fiberglass clad entry doors range from r 5 to r 6 excluding a window.
In new homes especially in cold climates in very energy efficient buildings.
Based on astm c518 calculation method the door has an r value of up to 11 but using astm c1363 tested operable the same door only have an r value of up to 3 5.
For example a 1 1 2 inch 3 81 cm thick door without a window offers more than five times the insulating value of a solid wood door of the same size.
Feather river doors 63 5 in.
The r value of a 1 3 4 inch wood door is 3 03.
How wood doors stack up.