We get this question often, "What is the r-value on this product?" and the answer is simple, though many insulation manufacturers are misleading about it.
We’re up front and honest, and think you should know that realistically, the R-value for ANY product that is a ¼" thick is approximately 1 to 1.5 maximum. This is true for ALL bubble-foil and foam-foil products, including BlueTex™ insulation products.
Many companies will claim their products have an R-value of R12 up to R15 (we’ve even seen up to R20!!) on similar products, but those claims are unfounded, inflated, or just plain DECEPTIVE!
Nothing ¼ “ thick would have an R-value that’s 15, and common sense tells you that's true.
For example: a common 3/4” piece of foam board has an r-value of 5. What the manufacturer is trying to claim is the R-value for the total assembly, including air gaps, two layers of wood sheathing and how it's installed, not just the R-value of the material/product alone. Here is a video that Ed did back in 2011 for our www.AtticFoil.com website that details the exact testing method they use to reach these crazy claims:
Does R-value Matter?
Maybe! It really depends on if the building is considered “conditioned” (meaning air conditioned and/or heated to maintain a constant temperature) , “non-conditioned” (basically just a metal box sitting outside in the sun like a barn, shed, garage, airplane hanger etc.), or “semi-conditioned” (maybe you want to run A/C or heat it occasionally)
For example, imagine you want to cool/heat a garage on Saturday afternoon while you work on your cars or that you have a building that is used part-time as a photo studio or workout room. These types of spaces would be considered semi-conditioned. Learn more about Conditioned vs. Non-Conditioned spaces.
The main issues with non-conditioned metal buildings is they tend to be 1) too extreme - either too HOT or too COLD, and 2) they sweat or have condensation issues. Having more R-value is not particularly useful in buildings like this since regular insulation does NOTHING to reflect the radiant heat.
Think about this for example: You are outside standing in the sun. You have a choice between a) getting INSIDE a big foam box or b) standing UNDER an umbrella. Which one would you choose? Of course you would choose the umbrella because you know that unless the big foam box was air conditioned, it would eventually get HOTTER inside the box than it would be under the umbrella! Right?!
Good news: you don't you need r-value to get the results you want! Remember, R-value isn’t really valuable in a non-conditioned metal building. Why? Because these buildings are not built to be a living space, even if you do occasionally run A/C or heat in them. Ultimately they're not fully conditioned and so they're not built (or insulated) like a normal living space.
Bottom line: Unless you're making a building (box) that is going to hold air inside at a constant temperature (i.e. 65-75ºF) via A/C or heat (basically a BIG version of a refrigerator), you do not need lots of r-value.
What Do I Need to Insulate My Metal Building?
Did you know virtually all of the heat entering from a roof is radiant heat? It is common knowledge that over 90% of heat from a roof is transferred downward into the area below via radiant heat. Here is a simple fact: the only thing between you and a 9,941ºF STAR (the sun) is a piece of metal! No wonder you’re HOT!!!
This is why using BlueTex™ insulation works so well! The foil side of BlueTex™ reflects 97% of that radiant heat (remember, radiant heat is invisible) and helps bring the inside of the building very close to ambient (outside) temperature. This is almost like a giant tree instantly shading the building! While, the foam layer in BlueTex™ is useful to act as a NEW interior surface that will stay warmer than the dew point during cold weather (to help stop condensation from forming). This works because instead of the metal surface being the inner most layer, now the BlueTex™ is. This new inner layer prevents warm moist air from ever reaching the cold metal and creating condensation. This works in both vented and non-vented buildings.
BlueTex™ Pro: 2mm Foil/White + EPE Foam insulation + Radiant Barrier for basic moisture prevention in metal buildings.
BlueTex™ Supreme: 6mm Foil + XPE Foam insulation + Radiant Barrier for total moisture prevention in metal buildings. Available in Foil/Foil or Foil/White styles.
So the best option for a metal building that's either non-conditioned or semi-conditioned (cooling/heating occasionally) is a radiant barrier + a little bit of R-value (if sweating/condensation is a problem). For more info, check out our installation pages here: How to Install BlueTex™ Insulation in Metal Buildings.