Archer Lodge, NC
5 miles east
Median home built 1996 (Clayton: 2006); Power from Duke Energy Progress (Clayton: a town system)
Attic insulation in Archer LodgeAttic Insulation in Clayton, NC
Blown-in attic insulation for Clayton, NC, in Johnston County, plus removal and air sealing.
About Clayton and Its Homes
Clayton grew around a stagecoach stop that became a North Carolina Railroad station in 1853, and it was incorporated in 1869. Its 2010 district nomination records Queen Anne houses, cotton mill houses, bungalows and Cape Cods in the old core, now ringed by neighborhoods built since the town began growing fast after 2000.
Clayton, in Johnston County, grew from 26,688 people in 2020 to 32,633 in 2025 (Census Bureau estimates), on 16.7 square miles. No town in Johnston County has more people than Clayton.
Clayton has about 11,500 housing units, 13 percent of Johnston County's; 63 percent of the town's households own their home.
Clayton at a Glance
- County: Johnston County
- Population: 32,633 (2025), 26,688 (2020), up 22.3%
- Land area: 16.7 square miles (1,949 people each)
- Housing units: about 11,500 (±479)
- Median year built: 2006 (±2); Johnston County: 2000
- Owner-occupied: 63% (±4); Johnston County: 76%
- Detached houses: 74% (±3); Johnston County: 76%
- Attached houses: 5% (±2)
- Apartments: 20% (±5)
- Climate zone: 3 on both maps
- ENERGY STAR target for Clayton attics: R-49 from bare, R-38 over 3 to 4 inches (R-value guide)
Census Bureau estimates for Clayton, 2020 to 2024 (± margin of error).
Clayton Homes and Their Attics
Clayton Cotton Mills Houses on East Front Street
Clayton Cotton Mills, organized in 1900, was the town's first cotton mill. The 2010 historic district nomination lists houses from its mill village on East Front Street and North Church Street. Its entries date them to about 1900. They describe one-story frame houses under side-gable roofs, some built as duplexes, with a gable-roofed rear ell or wing and a central or interior brick chimney. A house built that way can have two attics, the low main one plus a second space above the ell. We check and measure both separately, with extra care at the low edges, where ENERGY STAR notes insulation can be thinnest. The gap around the chimney gets metal flashing and heat-resistant caulk.
Bungalows and Cape Cods in the Historic District
Clayton's nomination ranks the bungalow with the Colonial Revival house as a main early twentieth century form in town. Its bungalows usually rise one and a half stories under wide eaves, with deep porches, and East Second Street has several from the 1920s, two of them Aladdin mail-order houses. From about 1940 into the 1950s, small Cape Cods with front-gable dormers followed. Either way, the second floor is tucked under the slope of the roof, walled off by low knee walls. On ENERGY STAR's list of where houses lose air, the open spaces behind knee walls and under them both appear. In these houses we seal those triangular side spaces and insulate them, then deal with the attic at the peak.
Newer Neighborhoods Around the Old Town
Clayton's growth plan says the town has grown quickly from 2000 on and expects more of the same. Most Clayton homes date from 1970 or later, which the Census figures on this page make plain. If your house has a powered attic fan, check how the attic around it is set up. ENERGY STAR warns that with blocked soffit vents and a poorly sealed ceiling, such a fan pulls cooled air out of the rooms and into the attic. So the ceiling leaks get sealed and the soffit vents opened before more insulation goes down.
Attic Insulation in Clayton
Some 8 percent of Clayton's homes predate 1970; if your joists show above the insulation, ENERGY STAR says to add more insulation.
From 1990 to 2009, 48 percent of Clayton homes were built to codes below ENERGY STAR's target; check their eaves, where ENERGY STAR says insulation is often thinnest.
The Local Climate
Clayton's center sits about 340 feet above sea level, under a mile from NOAA's Clayton Water Plant station, the best match for Clayton. The station's 1991 to 2020 normals average about 3,390 heating and 1,580 cooling degree days a year, so at Clayton's station, heating needs outweigh cooling.
Homes by Age: What It Means for the Attic
Some 74 percent of Clayton housing units are detached single-family houses.
In 2010 or later, 37 percent of Clayton homes went up; check their air sealing as well as the depth.
About 10 percent of Clayton's housing units predate 1980; nearly all predate the state's 1978 insulation rule too.
Homes by Year Built
- Before 1940: 2% (±1), about 235 units
- 1940s: 1% (±1), about 120 units
- 1950s: under 3%, about 155 units
- 1960s: 3% (±2), about 360 units
- 1970s: 3% (±1), about 330 units
- 1980s: 5% (±2), about 610 units
- 1990s: 14% (±4), about 1,580 units
- 2000s: 34% (±4), about 3,900 units
- 2010s: 33% (±5), about 3,800 units
- 2020 or later: 4% (±2), about 480 units
Air Sealing and Duct Sealing in Clayton
In Clayton, about 68 percent of homes heat with electricity; where that heat is forced air, ducts often run through the attic.
Air sealing comes first, as the EPA advises: wire and pipe holes, wall tops and soffits.
How Homes Here Are Heated
- Electricity: 68% (±6), about 7,700 households; Johnston County: 78%
- Piped gas: 28% (±4), about 3,100 households
- Bottled or tank gas: 3% (±2), about 340 households
Power, Gas and Rebates
Clayton, an ElectriCities public power town, runs its own electric system, and Duke Energy Progress serves some of its homes too. For gas, Clayton is in the Johnston County franchise of Piedmont Natural Gas, and 28 percent of the town's homes heat with piped gas.
Program to ask about in Clayton: ElectriCities energy audits (the town's electric system), home energy audits for member-town customers; ask the town's utility office. Before a job in Clayton, check its current terms; the Johnston County page lists every program.
Attic Insulation Removal in Clayton
In a Clayton attic, only wet, moldy or animal-soiled insulation is vacuumed out (ENERGY STAR's test), once the cause is fixed, and after mice that Clayton attic is sanitized and deodorized; dry, clean insulation stays.
Also Serving Near Clayton
Nearest to Clayton first.
Wilson's Mills, NC
7 miles southeast
Median home built 1997 (Clayton: 2006); Its NOAA station logs about 320 fewer heating degree days than Clayton's
Attic insulation in Wilson's MillsWendell, NC
9 miles northeast
Median home built 2010 (Clayton: 2006); Power from Duke Energy (Clayton: a town system)
Attic insulation in WendellGarner, NC
10 miles west
Median home built 2001 (Clayton: 2006); Its NOAA station logs about 240 more heating degree days than Clayton's
Attic insulation in Garner
Clayton Insulation FAQs
I live inside the Clayton Historic District. Do its rules reach my attic?
Not on its own. Clayton's district joined the National Register in 2010. The state's preservation office points out that listing alone places no restriction on owners who repair or alter a house at their own expense. The town's preservation page adds that its historic plaque program is voluntary. When the state compiled its local preservation commissions in 2023, Clayton had none on the list. Insulation and air sealing are indoor work. Before anything changes on the outside, such as new roof or soffit vents, check with the town.
Why is the bonus room over my Clayton garage so hard to keep comfortable?
Because it is boxed in by the garage underneath and attic on several sides. Building America advises air sealing any garage ceiling that has a room on top, and pressing the insulation up snug against the subfloor. ENERGY STAR lists the cavities behind and under knee walls as leak points, and a bonus room with short side walls has exactly that. We seal and fill those short walls, the little attics behind them and the ceiling overhead. We also insulate garages.
Did Clayton Cotton Mills put insulation in its mill houses?
No source says it did, and nothing required it. The mill village houses date from about 1900, and the state insulation rule covers only houses whose construction began January 1, 1978 or later. By then the mill had already shut, in 1976. So the amount up there can vary from house to house. The front block and the rear ell each get their own measurement, with you there, before any work starts.
Does attic insulation in Clayton need a permit?
Clayton Town Hall can say whether Johnston County Building Inspections Department, the town itself or another office handles permits in Clayton; ask before work starts.
Helpful Guides
- Median home built 2006: bonus rooms over garages
- An energy audit program from the town's own utility: home energy audits
Sources
Census Bureau figures for Clayton, NOAA normals for the Clayton Water Plant station, Clayton's municipal electric system (October 2026). Compiled by Insulation Pros. How the town pages are made.
Sources for the Clayton notes and questions (read October 20, 2026):
- Clayton, in The North Carolina Gazetteer (William S. Powell, 2nd ed., UNC Press 2010), NCpedia
- Clayton Historic District, National Register nomination (NC HPO)
- Comprehensive Growth Plan 2045, Town of Clayton
- Historic Preservation, Town of Clayton
- Year Structure Built (table B25034), Clayton town, American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau via Census Reporter
- Adding Attic Insulation, ENERGY STAR do-it-yourself guide
- Furnace Flues Require Special Sealing Techniques, ENERGY STAR do-it-yourself guide
- Attic Air Sealing Project, ENERGY STAR
- Building Construction Problem Areas, weatherization training text, Iowa Department of Health and Human Services
- 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)
- Floor Above Garage, Building America Solution Center (PNNL, U.S. Department of Energy)
- N.C. Gen. Stat. 143-139.2, Enforcement of insulation requirements; certificate for occupancy
- About Attic Ventilation, ENERGY STAR do-it-yourself guide
Clayton, NC
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Insulation Pros is an insulation contractor serving North Carolina, Clayton and the rest of Johnston County included.
Reach us
Send the square footage of your Clayton attic, or call (336) 870-3893.