new house insulation

[wxr]

I need professional help. How to inspect house insulation R-rate?
If builder claims R32 on the ceiling of garage, the contractor sprayed
R25. How can I tell the differences? Are these numbers rough
range or should be accurate?

Thanks for any inputs.

 

[Timothy's]

by look at the thickness. There are only few kinds of insulation material. They are quit standardized. You take a look what it is and find the thickness. After that go to home depot do a comparison. Some material may already have label printed on them.

 

[john19]

4" thickness is R24 and 6" is R32.