Gauge for Measuring Existing Wall Thickness

We need to make architectural drawings of some existing buildings. One of the difficulties is getting an accurate measurement the thickness of the walls. The interior walls are mostly gypsum board on steel studs and some of them might have sound insulation. The exterior walls are made of various materials including concrete, brick, insulation, steel studs, and gypsum board etc.

Does anyone know of a gauge that would help us get accurate measurements?

Something on the order of an ultrasonic wall thickness gauge but for architectural purposes?

Is there at least one door or window on each face of the building?

Yes, I was thinking of something like a fish finder.

Yes, we will be able to calculate most wall thicknesses through windows and doorways but there are several multi-floor buildings so a sonic wall thickness gauge would make things easier, if such a thing exists.

I wonder if the equipment that is used for ground penetrating radar would work on building walls and if so would the output be measureable in some way?

We use ultrasonic wall thickness equipment often to test chemical storage tanks.

Always, one material or another. An architectural wall would have many components so, I don't know if it would work for your intended use.

You might contact a manufacturer. Take a peek-a-boo at the TI-25S.

http://www.ultrasonicthicknessgauge.com/