Depending on the specific area of your home you are thinking of providing insulation for, there can be a great many different insulation standards you might have to comply with. Some areas, like the attic, ceiling or floor will require many layers of insulation until the desired r-rating is obtained. Others, like the exterior walls, will not need that much insulation, and you might even keep your investments at a minimum, depending on the area you live in.
The highest r-rating for insulation is associated with the attic of your home. This is where your house is most exposed to the elements, so this is where heat most often escapes. Some areas of the country in the north will even require you to keep a standard of R-49 and up to R-60 for attic insulation. It is always best to ask Longmont roofing companies that are experienced in roof insulation.
For ceilings and floors, the usual requirement is around R-25 and R30, however, if you live in warmer climates, you can go for floor ratings as low as R-13. On the other hand, living in the coldest parts of the United States will require you to adhere to a standard r-rating of R-30 for flooring and up to R-60 for your ceilings.
When it comes to walls, the actual insulation sheating can go from nothing to R-5 or R-6, while the cavity may range from R-13 to R-21. Depending on the standards in your location, there are fewer differences between ratings than in the case of some of the other areas of your home.