Crawl Space Encapsulation in Fairview, TN

The Harpeth River and its tributary, the Little Harpeth, are the county's primary waterways, and between their branches the ground is a run of ridges and hollows. Most houses sit on a slope of some degree, and a crawl space on a slope is rarely level end to end. The low corner collects damp air and, after a hard rain, sometimes the runoff itself. The high corner is where the fibreglass falls first, because nobody wants to work in an eighteen inch gap.

The other thing that shapes the work is the age spread. Fairview was incorporated in 1959, and the building stock runs from homes that predate that charter to houses finished in the last few years. A town of about 9,400 people this close to Nashville has grown in waves, and each wave built differently. The older homes tend to have vented crawl spaces with bare earth and batts hanging off the joists. The newer ones often have a tighter shell but the same open vents, because venting was the standard detail for decades.

Add it up and Fairview is a town full of crawl spaces that are not flooded but not dry. That in between condition is exactly what crawl space encapsulation is built to fix.

Drainage comes first. If water enters the crawl space when it rains, it is dealt with before any liner goes down. On sloped Fairview lots that usually means an interior drain along the low wall and a sump pump at the lowest point. A liner over an active water path just hides the water and buys a worse problem later.

Then the liner. A heavy reinforced liner goes over the ground, up the foundation walls and around every pier, seams overlapped and taped, the top edge fastened and sealed to the wall so moist ground air has no path up behind it. Most crawl space moisture comes out of the soil, not the vents, so this piece does most of the work.

Then sealing. The vents are closed and sealed off. The rim joist is sealed and insulated, usually with closed-cell spray foam, and gaps around plumbing, wiring and ducts are sealed at the same visit.

Last, conditioning. A sealed crawl space still needs its air managed. Depending on the house, that means a dedicated dehumidifier or a small amount of conditioned supply air. We size it to the space and tell you which option we picked and why.

• The low side of a sloped crawl space. This is where damp air pools on the ridge and hollow terrain, and where mould starts.
• A musty smell through the floors in summer. That is crawl space air moving up into the house. Sealing the ground stops the source.
• Cupped or crowning hardwood. Floors that take up moisture from below move, and a dry crawl space is how you stop the cycle.
• Fallen fibreglass under the floor. Wet batts sag and drop. Once the space is encapsulated, insulation stays where it was put.
• The rim joist. On older Fairview homes it is often bare framing. Sealing and foaming the rim is quick work while the liner crew is already down there.

The other common failure is skipping drainage because it is the least pleasant part of the job. If a contractor quotes a liner on a crawl space that takes on storm water, ask them where the water goes. If there is no answer, there is no plan.

We would rather tell you the job needs a drain and a pump than sell you a liner that cannot work.

See our spray foam insulation work, our crawl space encapsulation service, or the full service area.