Table of Contents
Does R-value depend on thickness?
The R-value depends on the type of insulation, its thickness, and its density.
How many inches thick should insulation be?
The higher the R-Value, the better the thermal performance of the insulation. The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.
What is the R-value of 1 inch thick?
6.2 1.08
At one inch thickness, EnerfoilTM achieves a 6.2 R-Value, or a 1.08 RSI….R-Value Chart for EnerfoilTM Rigid Foam Faced Insulation.

Thickness (Inches) | R-value (in I-P/Imperial) | RSI (R-value in Metric) |
---|---|---|
0.75 | 4.5 | 0.81 |
1.0 | 6.2 | 1.08 |
1.5 | 9.3 | 1.62 |
2.0 | 12.4 | 2.16 |
Does the thickness of insulation matter?
Thicker is better Insulation does the same thing for a house. The thicker the insulation, the better it works to reduce heat flow from the inside of a home to the outside during winter, and from outside to inside during summer.
What is the R-value of 3/4 inch Styrofoam?

STYROFOAM/BLUE BOARD 3/4″ 4’X8′ DOW R-VALUE: 4.0 (SQUARE EDGE)/ P2S FACING.
Can you over-insulate a house?
It is possible to over-insulate your house so much that it can’t breathe. The whole point of home insulation is to tightly seal your home’s interior. But if it becomes too tightly sealed with too many layers of insulation, moisture can get trapped inside those layers. That’s when mold starts to grow.
What R-value can you get in a 2×4 wall?
Fiberglass and rock wool batts—2×4 walls can hold R-13 or R-15 batts; 2×6 walls can have R-19 or R-21 products. Generally, batt insulation is the least expensive wall insulation material but requires careful installation for effective performance (see page 4).
Does plywood have an R-value?
In general, one inch of solid wood is considered to have an R value of 1. The general plywood R value per inch is 1.25.
How do you calculate the are – value of insulation?
The R-Value refers to a material’s ability to resist heat transfer at a certain thickness – the higher the better when looking for an insulation material. It is measured in m 2 .K/W. The R-Value is calculated as R = l/λ where l = the thickness of the material in metres and λ (lambda) is the thermal conductivity of the material in W/m.K.
Which insulation has the highest R-value?
Rigid Foam or Panel Insulation. The type of insulation with the highest R-Values,with a few exceptions,is rigid foam or panel insulation.
What is the your value of insulation?
R val {\\displaystyle R_{\\text {val}}} is the R-value (K⋅m 2/W),
How to estimate insulation thickness?
R-Value Explained. R-value refers to the resistance (R) insulation has to temperature conduction.