McAdenville, NC
5 miles southwest
Median home built 2010 (Mount Holly: 1999); 960 people, under a tenth of Mount Holly's population
Attic insulation in McAdenvilleAttic Insulation in Mount Holly, NC
Blown-in attic insulation for Mount Holly, NC, in Gaston County, plus removal and air sealing.
About Mount Holly and Its Homes
Mount Holly grew out of the Woodlawn community beside the Catawba River in northeastern Gaston County. The railroad came in 1860 and the Mount Holly Cotton Mill in 1875, and in 1879 the new town took the mill's name, with rows of worker housing to follow.
Mount Holly, in Gaston County, grew from 17,743 people in 2020 to 19,033 in 2025 (Census Bureau estimates), on 11.3 square miles. That makes Mount Holly the second-largest town in Gaston County.
Mount Holly has about 7,600 housing units, 7 percent of Gaston County's; 69 percent of the city's households own their home.
Mount Holly at a Glance
- County: Gaston County
- Population: 19,033 (2025), 17,743 (2020), up 7.3%
- Land area: 11.3 square miles (1,689 people each)
- Housing units: about 7,600 (±357)
- Median year built: 1999 (±3); Gaston County: 1982
- Owner-occupied: 69% (±3); Gaston County: 67%
- Detached houses: 75% (±1); Gaston County: 73%
- Attached houses: 8% (±2)
- Apartments: 15% (±4)
- Mobile homes: 1% (±1)
- Climate zone: 3 on both maps
- ENERGY STAR target for Mount Holly attics: R-49 from bare, R-38 over 3 to 4 inches (R-value guide)
Census Bureau estimates for Mount Holly, 2020 to 2024 (± margin of error).
Mount Holly Homes and Their Attics
Mill Rows on Alsace and Meller Streets
Charles Hutchison came to own six of the ten mills in Mount Holly by about 1920, and two of them left rows of worker housing. The 1996 nomination for the old Mount Holly Cotton Mill describes modest one-story houses on Alsace Street, put up by its second owner. At Woodlawn Mill, finished in 1907, the designer Stuart Cramer laid out 25 one-story frame dwellings, and the 2023 nomination finds survivors on Meller Street mixed with later infill. In a one-story house every room sits right under the attic, so each hole in that ceiling counts: light boxes, wire runs, plumbing and the chimney. We plug the big openings first, then insulate.
Newer Neighborhoods Away From the Mills
By the Census counts on this page, homes from 1970 and after make up most of Mount Holly. If a kitchen has a boxed-in soffit over its wall cabinets, from the attic side that box can be open, with insulation just lying over the hole. ENERGY STAR advice is to push the insulation back, close the opening with a stiff panel caulked all around, and only then spread the insulation over it again. The same goes for chases that carry ducts or a furnace flue up from the floors below, where the flue needs metal and heat-rated caulk rather than board.
Attic Insulation in Mount Holly
Some 27 percent of Mount Holly's homes predate 1970; if your joists show above the insulation, ENERGY STAR says to add more insulation.
From 1990 to 2009, 34 percent of Mount Holly homes were built to codes below ENERGY STAR's target; check their eaves, where ENERGY STAR says insulation is often thinnest.
The Local Climate
Mount Holly's center sits about 610 feet above sea level, 6 miles from NOAA's Charlotte Douglas Airport station, the best match for Mount Holly. The station's 1991 to 2020 normals average about 3,060 heating and 1,770 cooling degree days a year, so at Mount Holly's station, heating needs outweigh cooling.
Homes by Age: What It Means for the Attic
Some 75 percent of Mount Holly housing units are detached single-family houses.
In 2010 or later, 25 percent of Mount Holly homes went up; check their air sealing as well as the depth.
About 32 percent of Mount Holly's housing units predate 1980; nearly all predate the state's 1978 insulation rule too.
Homes by Year Built
- Before 1940: 6% (±2), about 480 units
- 1940s: 4% (±1), about 280 units
- 1950s: 10% (±2), about 790 units
- 1960s: 6% (±2), about 470 units
- 1970s: 5% (±2), about 400 units
- 1980s: 9% (±3), about 650 units
- 1990s: 10% (±2), about 790 units
- 2000s: 24% (±2), about 1,810 units
- 2010s: 22% (±3), about 1,670 units
- 2020 or later: 3% (±1), about 260 units
Air Sealing and Duct Sealing in Mount Holly
In Mount Holly, 42 percent of homes heat with electricity and 55 percent with piped gas; forced air from either moves through ducts.
Air sealing comes first, as the EPA advises: wire and pipe holes, wall tops and soffits.
How Homes Here Are Heated
- Electricity: 42% (±3), about 3,000 households; Gaston County: 57%
- Piped gas: 55% (±4), about 4,000 households
- Bottled or tank gas: 2% (±1), about 110 households
Power, Gas and Rebates
Duke Energy Carolinas serves most of Mount Holly, EnergyUnited its edges; your bill says which. For gas, Mount Holly is in the Gaston County franchise of Enbridge Gas North Carolina, and 55 percent of the city's homes heat with piped gas. Duke's free House Call fits many Mount Holly homes: 42 percent heat with electricity.
Rebate to check in Mount Holly: Smart $aver Insulate and Seal (Duke Energy; Insulation Pros is an approved trade ally). Before a job in Mount Holly, check its current terms; the Gaston County page lists every program.
Attic Insulation Removal in Mount Holly
In a Mount Holly attic, only wet, moldy or animal-soiled insulation is vacuumed out (ENERGY STAR's test), once the cause is fixed, and after mice that Mount Holly attic is sanitized and deodorized; dry, clean insulation stays.
Also Serving Near Mount Holly
Nearest to Mount Holly first.
Stanley, NC
6 miles northwest
Median home built 1979 (Mount Holly: 1999); Center about 230 feet higher than Mount Holly's
Attic insulation in StanleyLowell, NC
6 miles southwest
Center about 170 feet higher than Mount Holly's; 3,939 people, about a fifth of Mount Holly's population
Attic insulation in LowellCramerton, NC
7 miles southwest
Median home built 2001 (Mount Holly: 1999); 5,713 people, about a third of Mount Holly's population
Attic insulation in Cramerton
Mount Holly Insulation FAQs
Is my Mount Holly house part of the downtown historic district?
Probably not, unless it sits on Main Street itself. The Downtown Mount Holly Historic District, listed in 2012, covers parts of three blocks along Main Street and Central Avenue, and nearly all of it is commercial buildings and two churches. A private owner spending private funds is not bound by a Register listing in any case. The 2023 state list shows no local commission for Mount Holly itself. If the house is old, it still gets the usual checks of wiring, chimney and roof before insulation goes in.
Our home sits near the Catawba in Mount Holly. Does the river change anything about the attic?
Not directly. The river's big floods, like the July 1916 crest that damaged six mills including the Mount Holly Cotton Mill, are a question for floors and walls, not attics. Up there, damp insulation points to the roof, which ENERGY STAR says gets fixed before any new insulation goes in. After that, a house near the water is judged like any other: by its age, its framing, and where air slips up from the rooms below.
Could the old insulation in a Mount Holly attic be vermiculite?
It could: about 20 percent of Mount Holly's homes predate 1960. If a Mount Holly attic holds a pebble-like gray-brown or silver-gold fill, leave it undisturbed: the EPA says vermiculite may contain asbestos.
Does attic insulation in Mount Holly need a permit?
Mount Holly City Hall can say whether Gaston County Building Inspections, the city itself or another office handles permits in Mount Holly; ask before work starts.
Helpful Guides
- Power from Duke Energy Carolinas: high summer electric bills and home energy audits
Sources
Census Bureau figures for Mount Holly, NOAA normals for the Charlotte Douglas Airport station, Duke Energy Carolinas (October 2026). Compiled by Insulation Pros. How the town pages are made.
Sources for the Mount Holly notes and questions (read October 20, 2026):
- Mount Holly, in The North Carolina Gazetteer (William S. Powell, 2nd ed., UNC Press 2010), NCpedia
- Downtown Mount Holly Historic District, National Register nomination (NC HPO)
- Mount Holly Cotton Mill, National Register nomination (NC HPO)
- Year Structure Built (table B25034), Mount Holly city, American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau via Census Reporter
- Woodlawn Mill, National Register nomination, 2023 (NC HPO)
- Attic Air Sealing Project, ENERGY STAR
- Sealing Air Leaks in the Attic, ENERGY STAR do-it-yourself guide
- What Is the National Register of Historic Places?, NC State Historic Preservation Office
- Historic Preservation Commission Staff in North Carolina, listed by county, as of 2/20/2023 (NC HPO)
- Attic Insulation Project, ENERGY STAR
Mount Holly, NC
Open in Google Maps (opens in a new tab)Serving Mount Holly, NC
Insulation Pros is an insulation contractor serving North Carolina, Mount Holly and the rest of Gaston County included.
Reach us
Send the square footage of your Mount Holly attic, or call (336) 870-3893.