Required R Value For Attic Insulation

2015 code requires walls to be insulated with a minimum of r 20 or r 13 5 13 5 means r 13 cavity insulation plus r 5 insulated sheathing.

Required r value for attic insulation.

Where you live different climates require different insulation r values. Climate zone 1 consists of the following south florida counties. The higher the r value the better the thermal performance of the insulation. The homeowner could then check table 1 to find several choices.

Your home s age if your home is more than 10 year old you likely need more insulation. Achieving greater r values in exterior walls. What r value do i need. If structural sheathing covers 40 or less of the exterior continuous insulation r value shall be permitted to be reduced by no more than r 3 in the locations where structural sheathing is used to maintain a consistent total sheathing thickness.

R value is a measure of insulation s ability to resist heat traveling through it. Typically current best home building practices indicate an r 30 to r 38 for attic insulation. The recommended r value for attic floor insulation for this house is r 38. Recommended home insulation r values.

Recycled glass or sand that s melted and spun into fibers. It also happens if you place batts rated for one thickness into a thinner cavity such as placing r 19 insulation rated for 6 1 4 inches into a 5 1 2 inch wall cavity. In general to optimally isolate an attic on average an r value of the insulation is required ranging from r 50 to r 60. 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.

The table below shows what levels of insulation are cost effective for different climates and. The florida building code identifies two distinct climate zones. The further north northeast you go the colder it is and the more necessary r value will grow. Insulation which is compressed will not give you its full rated r value.

However this value varies not only on the basis of the type of insulating material but also on the area. 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. If the existing attic floor insulation has an r 11 insulation value then an additional r 27 would be needed to bring the attic floor insulation up to the level recommended for that house. You will need a higher r value of insulation if you live in the northeast than if you live in southern california.

Broward collier hendry lee miami dade monroe and palm beach and require a minimum r 30 attic insulation. The higher the r value the better the thermal performance of the insulation. There are many ways to retrofit a home with fiberglass and. Insulation level are specified by r value.