Insulating paints -- often referred to as radiant barrier paints -- typically do not perform as promised.
- A radiant barrier is defined as a product with an emissivity of .1 -- there is no paint on the market that meets this requirement.
- I could not find anywhere in the literature where it states the actual rating of the product.
- Closest I could find is .75, which is not a very good rating.
If you apply this product on the bottom of your roof sheathing, would it keep your attic cooler on a hot summer day? Probably a little, but not much. Using it in your garage will probably not get the results you are looking for.
A radiant barrier will not help with conduction and convection loss
Even if it did as it promised and reflected the heat, this only applies to radiant heat.
- In your bedroom, you are more than likely losing the majority of your heat through conduction and convection -- a radiant barrier will not help resist the heat transfer of either of these.
- You are better off air sealing and insulating at your floor.
If the budget allows, installing a rigid foam under your bedroom will help the performance tremendously.
For more information:
Read "Is a garage door insulation kit worth the time and money? Will the insulation make a difference in temperature for a room above it?" a Q&A answered by Lee Hall.