SIPs Wall and Roof RValues
RValues
Less air infiltration  no thermal bridging  a more energy efficient home

6" SIPs wall panel has an RValue of about 24

10" SIPs roof panel has an Rvalue of about 40
SIPS Wall & Roof RValues
For a more complete list of Rvalues download this file
R_Value_of_Quacent_SIPs.pdf
* Please click here to download Adobe Acrobat Reader to read our guide if you can not open our document.
RValue, UValue and Energy Efficiency
Everybody thinks “"Rvalue"” when they think about insulation.? Somehow, a myth has taken hold that more “"R" will cure all ills  in fact, most people think that R24 is twice as good as R12.? As we shall see, that just isn't so!? There is more to effective insulation than just piling on material.? In fact, an energy efficient building can be achieved with much lower Rvalues than we have been conditioned to believe.? The key is proper air sealing.? When you think about it, it is quite simple: if air can flow around your insulation, does it really matter how thick that insulation is?
The terminology used to describe insulation and energy efficiency can be confusing.? Here we attempt to demystify the terms and put some common sense into the debate.? Hopefully, when you are done reading you will find that it is not so mysterious after all!
Our examination consists of three brief parts:
WHAT EXACTLY IS RVALUE?
Definitions: Rvalue is the numerical reciprocal of Uvalue. That is: R = 1/U and U = 1/R For Example: If the Uvalue is 0.1, then the Rvalue is 10 (R=1/0.1) If the Rvalue is 12, then the Uvalue is 0.83 (U=1/12) One Btu is the amount of energy required to heat one pound of water from 58.5 to 59.5 degrees Farenheit. This is roughly the equivalent to the energy in one kitchen match. (Of course the metric system uvalue is different. To convert, multiply our standard uvalue by 5.6783) 
Rvalue is a numerical expression of a material's resistance to heat transfer. It is the numerical reciprocal of Uvalue and to understand these terms, it is necessary to first explain the Uvalue.
The Uvalue of a material is the number of British Thermal Units (Btus) that transfer through a 1 square foot area in one hour when the temperature difference between the two sides of the structure is 1 degree Farenheit. The smaller the Uvalue, the better the insulation properties of the material.
We can use Uvalues to help calculate a building's energy loss. Uvalues can be used in multiplication and division. Complex computer programs assist the professional energy rater in this process but the fundamentals are simple.
An example
The reason that we use two different values, U and R, to express the same thing is that they allow us to perform different types of calculations. As we just saw, U values can be used in multiplication and division problems. But Uvalues cannot be added or subtracted, Rvalues can!

THE RVALUE MYTH
The insulation value of a window is always expressed as a Uvalue.
The Six Factors of Heat Transfer We need to consider not one but six factors. Heat loss (or gain) happens in three ways:

Conduction
Convection
Radiation
Air Infiltration
Air Intrusion
Moisture
Conclusions
 The Rvalue of foam is as high or higher than traditional types of insulation and it controls conductive heat loss.
 Foam insulation does not allow airflow within itself so it blocks convective currents.

The cells in foam are tiny so there is very little temperature difference from one cell wall to the next  without temperature difference, there can be no radiant heat loss.
 Foam completely fills and seals any opening in the wall sheathing. There can be no air infiltration or intrusion.
 Air infiltration accounts for the vast majority of moisture in a wall system  without air infiltration, no moisture problem.
HOW MUCH RVALUE IS ENOUGH ?
There is more to an effective insulation system than piling on "R"s.
But can there be such a thing as too much Rvalue?