Manchester crawl space encapsulation — local context
If your Manchester crawl space is damp, musty, or open to bare soil, encapsulation seals it off for good. Manchester sits along the Merrimack River at Amoskeag Falls — a 55-foot drop the river makes right through the city center (Encyclopaedia Britannica) — so riverside and low-lying lots carry a high water table that drives moisture up into crawl spaces. The Amoskeag mills laid out the city and ran from 1838 to 1915 (Manchester Historic Association; Library of Congress HABS), leaving plenty of pre-1915 homes with dirt and fieldstone crawl spaces. Those open floors are also a radon path: Hillsborough County is EPA Radon Zone 2 (EPA), and New Hampshire's granite-bedrock radon runs roughly four times the national average (NH DHHS). Encapsulation = a 12-mil wall / 20-mil floor vapor barrier + dimpled drainage matting + dehumidifier + sump. Crawl space encapsulation runs $3,000–$25,000. Radon mitigation, if needed, is a separate add-on, typically $1,950–$2,250. See our crawl space services or radon mitigation.
What a recent customer said
"Gerald and his crew did an excellent job, first cleaning out all the debris and the dislodged insulation in the crawlspace. they were very communicative and understood my concerns and handled them professionally. When they were finished laying the sublayment and the top vinyl covering, carefully taping all the seams they put insulating foam around the perimeter, sealing the top of the vinyl. Gerald communicated two issues that were not part of the contract that I will subsequently take care of myself. Great job, very satisfied."
Frequently asked questions
Does my Manchester crawl space need radon mitigation along with encapsulation?
It might. Hillsborough County, where Manchester sits, is an EPA Radon Zone 2 (moderate potential, 2–4 pCi/L predicted), and New Hampshire's granite bedrock pushes statewide radon to roughly four times the national average (NH DHHS). The EPA notes elevated radon has been found in all zones and that every home should be tested. A dirt or fieldstone crawl space is a direct soil-gas entry path, so we recommend testing. Encapsulation seals the membrane; radon mitigation, if your test calls for it, is a separate add-on, typically $1,950–$2,250.
Why do older Manchester homes often have damp crawl spaces?
Manchester grew up around the Amoskeag mills, which laid out the city and operated from 1838 to 1915 (Library of Congress HABS; Manchester Historic Association). A large share of the housing stock dates from that mill era, the age of stone and fieldstone foundations with unconditioned dirt crawl spaces. Those open floors let ground moisture and humidity move freely. Encapsulation with a 12-mil wall / 20-mil floor vapor barrier, drainage matting, a dehumidifier, and a sump closes that off.
How much does crawl space encapsulation cost in Manchester?
Crawl space encapsulation runs $3,000–$25,000 depending on the size of the space, how much debris and old insulation needs clearing, and whether drainage and a sump are required. The system includes a 12-mil wall / 20-mil floor vapor barrier, dimpled drainage matting, a dehumidifier, and a sump. If a radon test comes back elevated — common in Hillsborough County's Zone 2 — mitigation is a separate add-on, typically $1,950–$2,250.