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?

I would recommend putting the PM entity in your fiance's name and have her be the lead on that.

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. 

We also can't service the multiple things breaking in her unit without her being home.

Hey Herb, long time no see!

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.