R-Value Calculator

mm = inches
RSI = R

Attics

Typical Truss
Raised Heel Trusses
Lumber Joists
I-Joists

Joist Offset

Joist Dimensions

2 x

Attic Component

Attic Component Thickness (mm) RSI
Outside Air Film 0.03
Roofing material:

Sheathing:


Insulation between joist:

Interior:


Interior Finish:


Inside Air Film 0.11
Total RSI:

Cathedral Ceilings/Flat Roofs

Lumber Joists
I-Joists

Joist Offset

Joist Dimensions

2 x

Ceiling Component

Ceiling Component Thickness (mm) RSI
Outside Air Film 0.03
Roofing material:

Sheathing:


Insulation between joist:

Interior:


Exterior:


Interior Finish:


Inside Air Film 0.11
Total RSI:

Exterior Walls

Single Wood Frame
Double Wood Frame with Double Top Plate
Structurally Insulated Panels (SIPs)
Insulated Concrete Form (ICF)

Stud Offset

Stud Dimensions

2 x

Wall Component

Wall Component Thickness (mm) RSI
Outside Air Film 0.03
Cladding:

Sheathing:


Insulation between studs:

Interior:


Exterior:


Concrete:


Interior Finish:


Inside Air Film 0.12
Total RSI:

Basement Walls

Single Wood Frame
Insulated Concrete Form (ICF)

Stud Offset

Stud Dimensions

2 x

Wall Component

Wall Component Thickness (mm) RSI
Outside Air Film 0.03
Insulation between studs:

Interior:


Exterior:


Concrete:


Interior Finish:


Inside Air Film 0.12
Total RSI:

Exposed Floors

Lumber Joists
I-Joists

Joist Offset

Joist Dimensions

2 x

Floor Component

Floor Component Thickness (mm) RSI
Outside Air Film 0.03
Subfloor:


Insulation between joist:

Exterior:


Interior Finish:


Inside Air Film 0.16
Total RSI:

Slab

Unheated Slab Below The Frost Line
Unheated Slab Above The Frost Line
Heated Slab

Slab Component

Slab Component Thickness (mm) RSI
Underslab:


Concrete:


Subfloor:


Interior Finish:


Inside Air Film 0.16
Total RSI: