One-day encapsulation. Lifetime liner warranty.

A vapor barrier is a sheet of plastic (typically 6–12 mil) laid across the crawl-space floor. It blocks ground vapor from rising into the crawl, but it doesn’t address humid air coming in through the vents and gaps in the foundation walls. A full encapsulation is a thicker reinforced liner (20+ mil) sealed across the floor AND up the foundation walls, with vents sealed, access door insulated, and a dehumidifier integrated to control humidity year-round. In East Tennessee’s humid subtropical climate, ground vapor is rarely the primary moisture source — humid outside air condensing on cool crawl-space surfaces is. A vapor barrier alone usually doesn’t end the moisture problem. Full encapsulation does.

Most East TN homes finish in a single day. A typical 1,500–2,500 sq ft single-story home with a standard crawl space takes 6–9 hours on site: clean the space, install the liner across floor and up walls, seal at perimeter and around piers, seal the vents, insulate the access door, install and plumb the dehumidifier, walk the homeowner through the system. Two-day installs happen on larger homes (3,500+ sq ft), homes with very low crawl clearance (under 18 inches), homes with significant structural repair preceding the liner, or homes where mold remediation is happening on the same trip. We tell you the timeline at the inspection — no surprises on install day.

The 20+ mil reinforced liner we install is warranted for the life of the home against punctures, seam failures, and wall-attachment failures that aren’t caused by external damage (rodent intrusion, homeowner activity in the crawl, ductwork rework). If the liner fails for a covered reason, we repair or replace it at no charge. The warranty is in the install contract you sign, not in a brochure. Note what’s NOT covered: the dehumidifier (manufacturer warranty applies, typically 5 years), structural problems that develop later, drainage problems caused by external grading changes, and damage from work done by other contractors in the crawl space after install.

In East Tennessee, yes — if you want the crawl space to stay below 55% relative humidity through summer. Here’s the physics: when you seal a crawl space, you stop the worst-case moisture cycle (vents pulling humid air in, condensation on cool surfaces). But you still need to remove residual moisture from the soil and from any small ongoing infiltration. Without a dehumidifier, a sealed East TN crawl drifts to 65–75% RH in summer, which is just above the threshold where mold can grow on wood. The dehumidifier is what keeps you out of that zone. Older homes without dehumidifiers had open vented crawls that “dried out” in part by exchanging humid air with the outdoors — which worked badly but worked enough that most homes survived. Modern sealed envelopes don’t have that mechanism, which is why dehumidification is essential.

We almost always remove existing plastic before installing new liner. Old vapor barriers in East TN crawls are usually torn, displaced, decomposing, and trapping moisture against the dirt — sometimes they’re the source of the smell, not a defense against it. Pulling the old material out, cleaning the surface, and installing fresh liner across clean ground is the right approach. The rare exception: if the existing plastic is recent, intact, and well-fitted, we may overlay it as a base layer. We’ll tell you which situation you have at the inspection.