They include:Solid phaseLiquid phaseGas phaseThink of them as ICE, Water, and Water Vapor.

It looks like you may have captured a free floating full torso vaporous apparition there.What are your plans for the rehab, if you don't mind me asking?

So if the homeowner wants to replace the particle board with OSB or plywood they have to pay the difference which in the overall scheme of things is quite negligible and well worth it.Belly boards aka vapor or varmint barrier is always a problem and needs to be checked regularly as plumbers and other tradesmen will tear it from limb to limb and not repair or replace it correctly if at all.

The sprayfoam is mold proof and vapor impermeable, thus sealing it off. 

You need to stop vapor transmission. 

Where there's an air/vapor/thermal barrier, that's the thermal envelope.

first,  there are no kits that convert a gas water heater to the little vapors that the instant water heaters put out.  

If nobody will be inside the house, vapor strips for the flies and mosquitos.

One tip from EMS when you're dealing with odors that nearly drive you out of the house, and you don't want to use a respirator: a dab of vicks vapor rub under your dust mask.

Least of all me, there is absolutely nothing a CG will advise me on from the size of a ring nail on shingles to the vapor liner below grade of the foundation, nothing, if I need an advisor I'll ask an engineer.And, contractors will do well to hook up with good investors.