Not a builder-grade 6-mil sheet held down with rocks. A real 20-mil reinforced polyethylene liner, mechanically fastened, taped at every seam, wrapped up walls and around piers. This is the moisture barrier that lasts 20+ years.
A licensed local crew — usually out in 24 to 72 hours. Written scope, fixed price, no pressure.
Vapor barrier work in Ballantyne is almost always a tear-and-replace, not a fresh install. Every 1990s and 2000s tract home in this ZIP has some kind of ground cover already down there — usually 6-mil clear builder plastic that was rolled out during original construction and has not been touched since. What is left of it after 20-plus years of foot traffic from HVAC service, pest control, and the occasional homeowner curiosity crawl is torn along every seam, bunched around the piers, and functionally not doing anything. The question on the inspection is not whether the current barrier is working — it is not — but whether the right scope is a straight vapor barrier upgrade or a full encapsulation.
Last month I was under a 1998 Piper Glen tract home off Rea Rd. Owner called because her HVAC contractor mentioned that the crawl was 'a mess' during a filter change, and she wanted a quote on 'just replacing the plastic.' Under the house: 40-inch clearance, original 6-mil clear plastic torn into rags along every seam, foil-faced fiberglass batts still up in the rim on the north wall but sagging out of half the bays on the south, eight 8-by-16 aluminum louvered vents all still open, hygrometer reading 78 percent RH at 76 degrees. The plastic itself was the least of her problems. What she needed was either a proper 20-mil ground cover with sealed vents and a dehumidifier — real encapsulation, per NC Res Code N1102.2.11 — or she needed to leave the crawl vented and accept that a new vapor barrier alone would not fix the humidity issue that was actually driving the HVAC contractor's comment.
Here is the honest breakdown I give homeowners in Ballantyne when they call asking for just a vapor barrier swap: a straight 20-mil ground cover replacement in an otherwise-vented crawl is a valid scope. It stops ground-source moisture from evaporating up into the joist system, it protects framing from direct water contact if there is any minor pooling, and it makes the crawl vastly cleaner and safer for anyone who has to work in it. It does not solve the summer humidity problem, because 80-plus percent of the moisture load in a vented Ballantyne crawl from May through September comes from outdoor air flowing in through the vents, not from ground evaporation. If humidity is the actual problem, vapor barrier alone will not fix it. If moisture protection and cleanliness are the actual problem, vapor barrier alone might be exactly right. My job on the inspection is to help you figure out which one you have.
What Ballantyne vapor barrier calls have in common with the encapsulation calls is the tear-out. Every 1990s and 2000s builder-installed 6-mil ground cover in this ZIP has to come out before any new material goes down, and that tear-out is not a five-minute job — the plastic is bonded to the dirt in some places, wrapped around piers in others, and there is usually 20 years of accumulated debris (fallen fiberglass, old HVAC filter media, rodent nesting material, the occasional dead lizard) that has to be bagged and hauled out too. Nobody quotes that correctly on the phone. Free on-site inspection is the only way to price it honestly.
Every Ballantyne vapor barrier job starts with the same conversation on the inspection: what problem are you trying to solve. If the answer is 'the crawl looks disgusting and my HVAC guy said something,' a 20-mil ground cover replacement in an otherwise-vented crawl is a valid scope and it delivers what the homeowner is actually asking for. If the answer is 'my humidity is out of control and my utility bill jumped,' vapor barrier alone will not fix that in Charlotte's climate and we need to be honest about it. About 40 percent of the vapor barrier calls I get in this ZIP end up scoping as full encapsulation once the homeowner understands the difference. About 60 percent stay as vapor-only, and that is fine — some people are not ready to commit to the electrical permit, the dehumidifier install, and the ARC submission for the exterior condensate line all in one project.
Assuming the scope is vapor-only, sequence is: exterior drainage first if the lot needs it. Most Ballantyne lots grade properly — the master-planned developments were engineered with real drainage — but there is a specific pocket along the McMullen Creek watershed where storm runoff sheets toward the foundation. On those lots, downspout extensions and a small regrade go in before we touch the interior. Fighting lot drainage from inside with a liner is a losing battle.
Then the tear-out. Original 6-mil comes out in sealed contractor bags along with any fallen fiberglass, old ductwork insulation, or accumulated debris. On the 2007-plus custom stock off Ardrey Kell Rd where the builder attempted a partial encapsulation, the tear-out is bigger — you are pulling 10-mil or 12-mil that was skirted around piers and taped to walls, and it takes a full day to strip cleanly. The block wall gets brushed to knock off loose efflorescence and dust so the new termination bar has clean substrate to bond against.
Then the 20-mil goes down. Every pier gets individually wrapped and taped with Polyken 337 double-sided PSA — not skirted, which is the shortcut that fails at year three because pier concrete wicks ground moisture up behind the plastic. Seams overlap 12 inches minimum. Perimeter runs up the block walls 12 inches, held with 1-inch by 1/8-inch aluminum termination bar fastened with 2-1/4-inch masonry screws every 12 inches, bedded in SikaFlex-1a. That termination is the difference between a vapor barrier that lasts 20 years and one that walks down the wall in year four.
Even on a vapor-only scope, I strongly recommend sealing the vents. The homeowner does not have to install a dehumidifier if they do not want to, but sealing the vents dramatically reduces the summer moisture load in the crawl and improves the value of the vapor barrier itself. If the customer wants to leave the vents open — usually because a home inspector or a code-official-in-a-past-life uncle told them vented crawls need ventilation — I will do it, but I document that decision in the scope. Charlotte's climate does not agree with the theory that vented crawls dry themselves. In practice they hold 80-plus percent RH from May to October regardless of vent size.
Material spec for Ballantyne vapor barrier is 20-mil reinforced woven poly — Viper CS, YellowGuard, or Americover depending on supplier availability. Not 6-mil, which is what the builder rolled out in 1998 and which is exactly what we are tearing out. Not 10-mil or 12-mil either, both of which take a knee through in year one under actual foot traffic. 20-mil has a woven scrim laminated between two poly layers — you can stand on it in work boots and it does not tear. Seams overlap 12 inches minimum with Polyken 337 or Nashua 357 double-sided PSA, top-taped after the seam is closed.
Perimeter termination is 1-inch by 1/8-inch aluminum termination bar (Insul-Bar or equivalent), fastened with 2-1/4-inch Tapcon or Simpson Titen masonry screws every 12 inches, bedded in SikaFlex-1a polyurethane sealant. Not acoustic caulk, which is what the builder used on the vent block-outs. Not butyl, which creeps in the heat and lets seams walk apart. Not just tape stuck to dusty block, which is the shortcut that fails inside two summers. The termination is the mechanical connection between the vapor barrier and the block wall — it is what holds the whole system in place for 20 years instead of four.
Piers get individually wrapped with 20-mil scrap material, taped at the top and bottom of the wrap, and mechanically fastened where needed. Ballantyne CMU piers are typically 8x8x16 block on 8-foot centers, 22 to 30 total piers in a 2,500-to-3,500 SF footprint. Wrapping each pier individually adds 20 to 30 minutes per pier over the alternative of skirting a continuous sheet around them, but skirting is what fails at year three when the pier concrete wicks moisture up behind the plastic and traps condensation in the gap. Wrapping is not optional on a job I stand behind.
Vent seals — even on a vapor-only scope where the homeowner is not committing to encapsulation — I strongly recommend closed-cell foam blocks cut to friction fit each 8-by-16 opening, bedded in SikaFlex-1a perimeter, and mechanically fastened exterior covers. Aluminum louvered vents specced by the original builder in 1998 are moisture pumps in Charlotte's climate, not dryers. Sealing them without adding a dehumidifier does not create a moisture trap the way homeowners sometimes worry — the vapor barrier prevents ground moisture from entering the crawl, and the remaining humidity load equalizes to the conditioned space above through stack effect. Not a perfect solution but meaningfully better than leaving the vents open.
Yes — Ballantyne is a regular vapor barrier route. Free on-site inspection anywhere in Ballantyne, fixed written quote before we touch anything.
Ballantyne vapor barrier work is almost universally a tear-and-replace on 20-plus-year-old builder 6-mil, and the honest scoping question I have to ask on every inspection is whether the homeowner is buying a partial fix (20-mil ground cover in an otherwise-vented crawl) or committing to the full encapsulation upgrade that would actually solve the humidity problem — because in this climate a vapor barrier alone does not do the second job.
28277, 28270. All Mecklenburg County addresses covered.
12-mil will work on paper. In practice, the first HVAC tech who crawls in there to change a filter puts a knee through it, and now you have a hole feeding humidity right back into your system. Ballantyne crawls have easier access than the older 1960s Cotswold stock, which means HVAC contractors, pest control, and the occasional homeowner actually do go under these houses regularly — foot traffic is real, and 12-mil does not survive it. 20-mil has a woven scrim that holds up under work boots and does not tear at seams. The material cost difference is small compared to the labor of tearing the whole thing out and redoing it in year six. I have never regretted specing 20-mil. I have regretted the two times early on I let a homeowner talk me down to 12-mil to save a little money. Both jobs came back.
No, but it will not get better either. Here is the honest breakdown: in a vented Ballantyne crawl from May through September, 80-plus percent of the moisture load comes from outdoor air flowing in through the foundation vents, not from ground evaporation. Replacing the ground cover with 20-mil eliminates the ground-evaporation component, which is real and measurable in absolute terms but small compared to the vent-driven load. The remaining humidity is what the vents bring in every day. Sealing the vents in addition to the new vapor barrier makes a much bigger difference than the vapor barrier alone. Adding a dehumidifier on top of both is what actually holds 55 percent RH through a Charlotte August. Vapor barrier alone does not make anything worse. It just does not fully solve the humidity problem — and I want you to know that going in, not learn it in July when the crawl smells the same as it did last year.
Almost never. The 20-mil liner goes down on the crawl floor and up the pier walls — the HVAC ductwork typically runs 6 to 18 inches above the floor in Ballantyne construction, well above the vapor barrier work zone. Where we do have to work around ductwork is on the pier wraps directly under a supply trunk or a return chase, and on the wall termination where a duct penetrates the block wall to exit the crawl. Those are trim jobs, not duct-moving jobs. If your ducts are damaged, sagging, or disconnected — which happens on 20-plus-year-old Ballantyne systems — I will flag that as an HVAC contractor referral, but I do not touch the ductwork itself. My scope is the vapor barrier and any structural repair. HVAC is a separate trade with a separate license.
Almost certainly it does not. Builder-installed vapor barriers in 2000s Ballantyne construction were typically 6-mil clear plastic rolled out over graded dirt with seams overlapped 6 inches or less, no tape, no pier wraps, and no perimeter termination on the block walls. Twenty years of foot traffic from HVAC service and pest control has torn every seam. The plastic is bunched around the piers where it was skirted rather than wrapped. On the 2007-plus custom stock along Elm Ln and the Ardrey Kell district, the builder sometimes installed 10-mil or 12-mil with a couple of pier wraps for the marketing photos and tape stuck to the block walls — that stuff failed inside five years and is now in the same condition as the older 6-mil. The way to check: drop through your crawl hatch with a headlamp and look at the seams. If you can see dirt through any seam or around any pier, the vapor barrier is failing. It is time to redo it.
Free on-site Ballantyne inspection. Fixed written quote. Call (980) 227-1769 or book below.