Best R Value Insulation For Attic

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.

Best r value insulation for attic.

Recommended insulation levels for retrofitting existing wood framed buildings. Achieving greater r values in exterior walls. Cellulose has an r value of 3 5 inch thickness. If you put an air permeable insulation material over a hole in your ceiling you may have comfort indoor air quality durability and efficiency problems.

Here are the most common insulation materials listed in order of lowest to highest r value. Let s say the insulation you ve selected has an r value of three per inch and. There are many ways to retrofit a home with fiberglass and. You only need four inches of r 3 5 cellulose in a wall cavity to exceed the recommended insulation level of r 13 for walls located in zone 4.

The higher the r value the better the thermal performance of the insulation. Loose fill cellulose is rated between r 3 2 and r 3 9 per inch making it one of the least efficient insulation materials available. Therefore it needs to be fireproof. Before you ever get insulation anywhere near the attic though make sure that you get the air leakage sites sealed up.

Cavity wall insulation technique determining what is the best house insulation polyurethane foam has the highest r value 6 5 inch thickness of all the spray in insulation but it is also the most expensive. It is manufactured from recycled paper. Your home s age if your home is more than 10 year old you likely need more insulation. In general an attic s r value should be between r 30 and r 49.

Where you live different climates require different insulation r values. In particularly cold climates you might go up to r 60. Existing 3 4 inches of insulation. Lighter in weight than cellulose or mineral wool but it settles more than those materials so you ve got to put in a thicker layer to get the protection you need.

You will need a higher r value of insulation if you live in the northeast than if you live in southern california. However cellulose is inexpensive environmentally friendly and easy to install behind finished walls. Recycled glass or sand that s melted and spun into fibers. But newer homes in central and southern arizona are insulated to ratings of r 30 to r 38 while newer homes in northern arizona generally have attic insulation at r 60 because of colder winters.