Required R Value For Attic Insulation

The further north northeast you go the colder it is and the more necessary r value will grow.

Required r value for attic insulation. Insulation which is compressed will not give you its full rated r value. Your home s age if your home is more than 10 year old you likely need more insulation. Recycled glass or sand that s melted and spun into fibers. Climate zone 1 consists of the following south florida counties.

Recommended home insulation r values. 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. Where you live different climates require different insulation r values. 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.

In general to optimally isolate an attic on average an r value of the insulation is required ranging from r 50 to r 60. The higher the r value the better the thermal performance of the insulation. There are many ways to retrofit a home with fiberglass and. 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.

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. Insulation level are specified by r value. R value is a measure of insulation s ability to resist heat traveling through it. 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.

What r value do i need. Typically current best home building practices indicate an r 30 to r 38 for attic insulation. The higher the r value the better the thermal performance of the insulation. Broward collier hendry lee miami dade monroe and palm beach and require a minimum r 30 attic insulation.

The table below shows what levels of insulation are cost effective for different climates and. This can happen if you add denser insulation on top of lighter insulation in an attic. You can achieve better thermal performance in your attic by adding an additional layer of insulation. However this value varies not only on the basis of the type of insulating material but also on the area.

You will need a higher r value of insulation if you live in the northeast than if you live in southern california. The recommended r value for attic floor insulation for this house is r 38. Achieving greater r values in exterior walls. 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.