California Attic Insulation R Value

And zones 5 through 8 need r49 to r60.

California attic insulation r value. Zones 2 and 3 r30 to r60. The insulation must also meet the manufacturer s specified minimum weight per sq ft. Achieving greater r values in exterior walls. Where you live different climates require different insulation r values.

What i m talking about is a house with ducts in unconditioned space especially an unconditioned attic. If kraft or foil faced insulation is used it should be installed per manufacturer recommendations to minimize air leakage and avoid sagging of the insulation. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7 along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. As you can imagine the r value for insulating an attic in alaska isn t necessarily going to be the same for insulating an attic in california.

Recommended insulation levels for retrofitting existing wood framed buildings. Zone 4 r 38 to r 60. Insulation leakage radiant barrier r 30 at ceiling attic floor r 38 at ceiling attic floor fiberglass below roof deck between rafters air handler ducts in the attic option b 1 r 6 or r 8 depending on cz all with 5 leakage 2 3 5 7 10 16 r 13 4 8 9 11 15 r 19 air handler ducts in conditioned space option c 1 16 r 6 all with 5 leakage. Minimum insulation r value requirements non residential above roof deck.

Sacramento and most of california are in zone 3 which requires attic insulation with an r value between 30 and 60. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. Batt insulation should fill the wall cavity evenly. In fact there are building codes that require a certain r value for insulation depending on where in the country you live.

If we put ducts in unconditioned space. State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1 2010. Existing 3 4 inches of insulation. Zone 1 for example should have attic insulation of r30 to r49.

As a benchmark one inch of solid wood has an r value of 1. Our r value cognitive dissonance. I m in georgia iecc climate zone 3 where our current state code requires r 13 in exterior walls r 18 in attic kneewalls r 19 in floors and r 30 in ceilings. The higher the r value the better the thermal performance of the insulation.

For the corresponding r value. 3 r 20 4 r 20 state only ca california 2016 building energy efficiency standards 2 r 25 3 r 25 4 r 30 5 r 30 6 r 30 state local co colorado 2012 iecc 4 r 25 5 r 25 6 r 30. You can achieve better thermal performance in your attic by adding an additional layer of insulation. That s where this nifty energystar chart comes in handy.