U. S. department of energy

recommendations by geographic locations

1

V

V

V

R-49

R-38

R-18

R-25

R-19

R-8

R-11

R-10

1

V

R-49

R-60

R-28

R-25

R-19

R-8

R-19

R-15

2

V

V

V

R-49

R-38

R-18

R-25

R-19

R-8

R-11

R-10

2

V

R-49

R-38

R-22

R-25

R-19

R-8

R-19

R-15

3

V

V

V

V

R-49

R-38

R-18

R-25

R-19

R-8

R-11

R-10

4

V

V

V

R-38

R-38

R-13

R-13

R-19

R-4

R-11

R-4

4

V

R-49

R-38

R-18

R-25

R-19

R-8

R-11

R10

5

V

R-38

R-30

R-13

R-11

R-13

R-4

R-11

R-4

5

V

V

R-38

R-38

R-13

R-13

R-19

R-4

R-11

R-4

5

V

R-49

R-38

R-18

R-25

R-19

R-8

R-11

R-10

6

V

R-22

R-22

R-11

R-11

R-11

(c)

R-11

R-4

6

V

V

R-38

R-30

R-13

R-11

R-13

R-4

R-11

R-4

6

V

R-49

R-38

R-18

R-25

R-19

R-8

R-11

R-10

(A)	R-18, R-22, and R-28 exterior wall systems can be achieved by eithen cavity insulation or cavity insulation with insulating sheathing. For 2 in x 4 walls, use either 3 1/2 in thick R-15 or 3 1/2 in thick R-13 fiber glass insulation with insulating sheathing. For 2 in x 6 walls, use either 5 1/2 in thick R-21 or 6 1/4 in thick R-19 fiber glass insulation.
(B)	Insulate crawl space walls only if the crawl space dry all year, the floor above is not insulated, and all ventilation to the crawl space is blocked. A vapor retardes (e.g. 4- or 6-mil polyethylene film) shoul be installed on the ground to reduse moisture migration into the crawl space.
(C)	No slab edge insulation is recommended.