Moisture
Is Crawl Space Encapsulation Worth It?
Updated · Holdfast editorial · 2 min read
What are the benefits?
- Warmer floors
- Less mold and odor
- Protected joists
- Fewer pests
How do you do it right?
What does a good encapsulation include?
- Drainage and a sump if water collects
- Heavy vapor barrier on floor and walls, sealed at seams
- Vents sealed and rim joists insulated
- A dehumidifier sized to the space
- Access door sealed
When does encapsulation pay off, and when doesn't it?
Encapsulation seals the crawl space from the ground and outside air: a heavy vapor barrier over the floor and up the walls, sealed vents, and usually a dehumidifier. It's worth it when the crawl is the source of a problem you can feel upstairs.
- Worth it: musty odors in the house, cold floors, condensation on ducts or pipes in the crawl, damp or moldy insulation, wood that reads high on a moisture meter
- Fix first: standing water or seepage; drainage and a sump come before a vapor barrier, or the barrier just holds water in
- Probably not needed: a dry crawl with a sound vapor barrier, dry wood and no odor
What are crawl spaces like under older Mahoning Valley homes?
Much of the valley's housing is old: in Youngstown, Struthers and East Liverpool, over 70% of homes were built before 1960 (Census ACS). Crawl spaces from that era often have bare soil, no vapor barrier and open vents, which let ground moisture and humid summer air in. Those are the crawls where encapsulation makes the biggest difference, once any water entry is handled.
Call a professional if
- Standing water or active seepage in the crawl
- Visible mold growth on joists or subfloor
- Rotted or soft sill plates or joists
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About crawl space encapsulationWhat else do people ask about this?
Does encapsulation reduce energy bills?
It can make floors warmer and reduce humidity load, but savings vary by home.
Does an encapsulated crawl space need a dehumidifier?
Usually, or conditioned air from the HVAC system, to keep humidity down.
Where can I verify this information about your home?
- 1U.S. Environmental Protection Agency: MoldGuidance on moisture control and keeping indoor humidity low to prevent mold.
- 2U.S. Census Bureau: QuickFactsHousing and population facts for your home, including the age of local housing stock.
- 3USDA Natural Resources Conservation Service: Web Soil SurveyLook up soil drainage class and shrink-swell potential for any lot in your home.
- 4Federal Trade Commission: Hiring a ContractorWhat to check before hiring: licensing, insurance, written estimates and payment terms.
Every home differs; editorial standards.