Go to Shermin Williams stores and buy a "wet film thickness gauge". 

You don't need a professional filming you, it can be as simple as filming yourself with your cell phone.

The film isn't supposed to be a how-to guide....

Next time, work on clear instructions for your vendor: control the dust by covering vents, taping up plastic film at the door to the renovated room, and make them include cleanup in their fixed bid. 

If you need any background on me, I'm a film/game/trailer composer and am the music supervisor of a trailer music library. 

The author of "Bluefish" was on the biggerpockets podcast and tells a story of young kids filming a commercial for their products in parking garage in L.A. next to a Lamborgini, that is clearly not their car.

blow a light film into cracks, under cabinets, stove, bathroom cabinets, etc. 

The filmed a commercial to it!

I took that $235,000 that I netted from that property and purchased a larger home that I now rent out to film studios and will also be pulling a HELOC out to purchase my rental properties.Without purchasing that first starter home I wouldn't have been able to do any of this.  

If I felt a cold draft from a window, I covered it with the plastic film kit in the winter.