Sealed · Drained · Dehumidified
That dirt-floor crawl space under your addition is a humidifier pointed at your house. Sealing it changes the air upstairs, protects the framing, and usually pays for itself in energy alone.
Building science calls it the stack effect: air moves upward through a house, and much of what you breathe on the first floor rose out of the crawl space below it. In NEPA that means moisture off damp valley soil, the musty smell that never leaves the den over the crawl, summer humidity your dehumidifier can't beat, and — in the worst cases — rot working through joists and mold tracking along the subfloor. Vented crawl spaces, the old standard, make it worse: summer air pouring through the vents condenses on cool surfaces and adds water rather than removing it.
Encapsulation flips the design: a heavy sealed vapor barrier across the floor and up the walls, vents closed, seams taped, drainage or a sump below the liner where groundwater demands it, and a properly sized dehumidifier keeping the space dry year-round. The crawl becomes clean, semi-conditioned storage — and the floor above it stops being cold in January and clammy in July.
Signs your crawl space is the problem: musty odor strongest in summer; cupping hardwood floors; cold first-floor rooms in winter; allergies that flare at home; visible standing water or damp soil under there; insulation hanging off the joists like laundry. Any two of those and the free inspection will pay for itself in clarity.
Most Scranton-area encapsulations run $3,000–$8,000 depending on square footage, drainage needs, and access — with basic vapor-barrier-only projects below that and large or wet crawls above. Firm written quote after the free look-under.
A loose plastic sheet slows evaporation and little else. Encapsulation seals the space: liner mechanically fastened and taped up walls, vents sealed, water managed below, humidity managed above. One is a tarp; the other is a system with a warranty.
The venting-for-moisture idea has been tested and retired — in humid summers, vents ADD moisture. Modern building science (and code allowance for closed crawl spaces) favors sealed and conditioned. Your framing prefers it too.
No — water first, always. Drainage matting and a sump go in beneath the liner so the space stays dry under the barrier. Sealing over standing water just gift-wraps the problem.
Typically yes — sealed crawls stop the winter chimney of cold air under your floors and cut the summer humidity load on your AC. Homeowners commonly notice the first-floor comfort change within days.
Scranton, Dunmore, Dickson City, Taylor, Old Forge, Moosic, Clarks Summit, Carbondale & Lackawanna County.
Call (570) 555-0152