Jon,

I would not trust that.

There are many things which could affect those readings:
- studs
- furring strips
- insulation touching the wall
- insulation not touching the wall
- air leakage into the wall
- drywall nail or screw
- and the list could go on and on

__________________
Jerry Peck, Construction / Litigation Consultant
Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )