Crawl Space Vapor Barrier Installation in Raleigh, NC
20-mil reinforced liner over bare Piedmont clay floors. Priced for Wake County homes on Cecil Clay Loam over granite bedrock.
How much does crawl space vapor barrier installation cost in Raleigh, NC?
Crawl Space Vapor Barrier Installation in Raleigh, NC costs $4,500 to $10,500 for a typical home. A crawl space vapor barrier in the Triangle costs $1,800 to $4,200 and covers the dirt floor with a 20-mil reinforced polyethylene liner, seam-taped and mechanically fastened to foundation walls to block ground moisture from evaporating into floor joists.
Raleigh soil and why crawl spaces fail here
Raleigh sits on the Cecil soil series, a red clay loam weathered from granite and gneiss of the Raleigh Belt. Beneath the topsoil, dense clay subsoil sits on saprolite and shallow bedrock, so the 46 inches of rain the city receives each year cannot percolate downward. Water moves laterally instead, riding the top of the clay until it reaches a foundation footing.
Inside-the-Beltline homes from the 1940s through 1960s were built with open vents and bare dirt floors. The stack effect pulls that soil dampness up through the floor system and into ductwork, seeding Cladosporium colonies on subfloor sheathing and carrying musty air into bedrooms upstairs.
From Five Points and Hayes Barton to Brier Creek and Wakefield, Raleigh's housing stock spans eighty years of construction standards, and almost none of the pre-2005 crawl spaces were sealed.
Scope included in Raleigh
- 20-mil reinforced woven liner rated far above the builder-grade 6-mil poly used across Wake County subdivisions
- Seams double-taped and overlapped 12 inches, piers wrapped and sealed individually
- Termite inspection gap maintained per North Carolina building code
- Drainage matting added where Cecil clay perches water beneath the liner
Signs you need this
- Bare dirt or torn plastic under the house
- Musty odor rising into hallways and closets
- Condensation on ductwork in summer
Neighborhoods we cover in Raleigh
Other services in Raleigh
Vapor Barrier in nearby Triangle towns
See the full Raleigh crawl space guide or the Triangle-wide vapor barrier overview.
Vapor Barrier in Raleigh: common questions
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