I usually will put up a vapor barrier over the studs, then concrete board or green drywall, then I use a waterproof membrane such as Kerdi.

If the smoke does bother A and B, maybe you should ask C or D to start using a vaporizer.

Its a vapor barrier, but also insulates and reflects heat as well.

And due to the vapor barrier, (a huge plastic sheet) all the little (and not so little ) poopies stayed nice moist and fresh!

.- Blown insulation in attic- New deck- Crawlspace remediation and encapsulation- french drain, sump pump, blown insulation, vapor barrier, dehumidifier.- Landscaping front and back beds.

There does not appear to be a vapor barrier.

Once you get into framing, there's a lot of things to know about vapor barriers, ground contact lumber, mold-resistant materials, etc.In my opinion, this isn't a DIY type of project unless you're a licensed contractor.

Got an expensive termite & crawl space repair needing to be done before closing required by the underwirter, totaling about 8K, including termite treatment, organic growth treatment, digging out dirt for enough crawlspace height clearance, stiff legs insulation, vapor barrier, 6 crawl space vents (2 powered & 4 regular), and 5 vent wells. 

They are not down lights and often are covering more distance than I need and 150w halogen or mercury vapor is an overkill.I also don't like battery operated LESs, I have a power source.I know they sell those socket extension with motion deyecyion for about $20, is this my solution?

be sure to remove the vapor barrier