{
 "page": "how-central-ohio-houses-were-built-by-era.html",
 "url": "https://www.openshowerco.com/how-central-ohio-houses-were-built-by-era.html",
 "title": "How Central Ohio houses were built, era by era, from the footing to the wall behind the tile",
 "record": "kb-wave-ten-2026-09",
 "generated": "2026-09-08",
 "how_to_read": "Every sentence on the page traces to one of these claims. status \"verified\" means two independent publishers state it; \"single\" means one named publisher, named in the page's sentence; \"conflict\" means the documents disagree and the page prints both.",
 "claims": [
  {
   "id": "C1",
   "claim": "The federal rehabilitation guide says most houses with basements built in the twentieth century have concrete basement floor slabs, typically four inches thick.",
   "status": "single",
   "quote": "Most houses with basements built in this century have concrete basement floor slabs",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 1: Foundations",
     "url": "https://www.huduser.gov/portal/Publications/PDF/found.pdf",
     "published": "1997-06"
    }
   ]
  },
  {
   "id": "C2",
   "claim": "The National Park Service says portland cement was first manufactured in the United States in 1872 but was not in common use across the country until the early twentieth century, and that by the 1930s most masons used a mix of equal parts portland cement and lime putty.",
   "status": "single",
   "quote": "Portland cement was first manufactured in the United States in 1872",
   "sources": [
    {
     "publisher": "National Park Service",
     "title": "Preservation Brief 2: Repointing Mortar Joints in Historic Masonry Buildings",
     "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-02-repointing.pdf",
     "published": "1998"
    }
   ]
  },
  {
   "id": "C3",
   "claim": "The National Park Service dates a much greater acceptance of concrete to after 1900, crediting the improvements that followed the rotary kiln Ernest Ransome introduced to United States cement production two years after his 1884 patent for twisted reinforcing bars.",
   "status": "single",
   "quote": "led to a much greater acceptance of concrete after 1900",
   "sources": [
    {
     "publisher": "National Park Service",
     "title": "Preservation Brief 15: Preservation of Historic Concrete",
     "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-15-concrete.pdf",
     "published": "2007"
    }
   ]
  },
  {
   "id": "C4",
   "claim": "The National Park Service calls casting concrete blocks to imitate quarried stone a popular technique from the late nineteenth century to the middle of the twentieth.",
   "status": "single",
   "quote": "to mimic quarried stone was a popular late 19th- to mid 20th-century technique",
   "sources": [
    {
     "publisher": "National Park Service",
     "title": "Preservation Brief 16: The Use of Substitute Materials on Historic Building Exteriors",
     "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-16-substitute-materials-2023.pdf",
     "published": "2023"
    }
   ]
  },
  {
   "id": "C5",
   "claim": "In the Census Bureau's series, 72 percent of new single-family houses completed in the Midwest in 1971 had a full or partial basement and 50 percent in 2025, against 36 percent and 16 percent for the country.",
   "status": "single",
   "quote": "Type of Foundation in New Single-Family Houses Completed",
   "sources": [
    {
     "publisher": "U.S. Census Bureau",
     "title": "Characteristics of New Housing: Type of Foundation in New Single-Family Houses Completed",
     "url": "https://www.census.gov/construction/chars/xls/foundation_cust.xls",
     "published": "2026"
    }
   ]
  },
  {
   "id": "C6",
   "claim": "The Residential Code of Ohio requires an exterior footing to be placed not less than 12 inches below the undisturbed ground surface, and separately requires protection from frost.",
   "status": "single",
   "quote": "Exterior footings shall be placed not less than 12 inches",
   "sources": [
    {
     "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
     "title": "Rule 4101:8-4-01, Foundations (Residential Code of Ohio)",
     "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-4-01",
     "published": "2019-07-01"
    }
   ]
  },
  {
   "id": "C7",
   "claim": "The City of Columbus fills in the blank the state leaves: its building department publishes a frost line depth of 32 inches, a ground snow load of 20 pounds per square foot, seismic design category B and, reproduced from the state's own table, a severe weathering classification.",
   "status": "single",
   "quote": "Climatic and Geographic Design Criteria per Section R301.2 of the Residential Code of Ohio",
   "sources": [
    {
     "publisher": "City of Columbus, Department of Building and Zoning Services",
     "title": "Construction Industry Communication #09, Climatic and Geographic Design Criteria per Section R301.2 of the Residential Code of Ohio",
     "url": "https://www.columbus.gov/files/sharedassets/city/v/2/building-and-zoning/cics/cic-09-climatic-geographic-design-2026.pdf",
     "published": "2006-07-13"
    }
   ]
  },
  {
   "id": "C8",
   "claim": "The federal rehabilitation guide says that in the first half of the nineteenth century machine-sawn lumber and factory-made nails led to lighter framing, including braced framing and balloon framing.",
   "status": "single",
   "quote": "the introduction of machine-sawn lumber and factory-made nails led to lighter structural systems",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 2: Exterior Walls",
     "url": "https://www.huduser.gov/portal/Publications/PDF/walls.pdf",
     "published": "1999-08"
    }
   ]
  },
  {
   "id": "C9",
   "claim": "Two federal sources put the change to platform framing earlier than the usual telling: the rehabilitation guide says balloon framing had largely been replaced by the beginning of the Second World War, and the Agriculture Department's 1955 house-building handbook already calls the platform method the more general one.",
   "status": "verified",
   "quote": "balloon framing had largely been replaced with platform framing",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 2: Exterior Walls",
     "url": "https://www.huduser.gov/portal/Publications/PDF/walls.pdf",
     "published": "1999-08"
    },
    {
     "publisher": "U.S. Department of Agriculture, Forest Service, Forest Products Laboratory",
     "title": "Wood-Frame House Construction, Agriculture Handbook No. 73",
     "url": "https://archive.org/details/WoodFrameHouseConstruction",
     "published": "1955-02"
    }
   ]
  },
  {
   "id": "C10",
   "claim": "The federal lumber standard records its own beginning and its most consequential change: Commerce Department work produced Simplified Practice Recommendation R 16 in 1924, and the 1970 edition established separate sizes for dry and green lumber.",
   "status": "verified",
   "quote": "development and publication in 1924 of Simplified Practice Recommendation R 16",
   "sources": [
    {
     "publisher": "National Institute of Standards and Technology, U.S. Department of Commerce",
     "title": "Voluntary Product Standard PS 20-25, American Softwood Lumber Standard",
     "url": "https://www.nist.gov/document/ps-20-25-final",
     "published": "2025-01"
    },
    {
     "publisher": "U.S. Department of Agriculture, Forest Service, Forest Products Laboratory",
     "title": "Commercial Lumber, Round Timbers, and Ties, chapter 6 of the Wood Handbook (General Technical Report FPL-GTR-282)",
     "url": "https://www.fpl.fs.usda.gov/documnts/fplgtr/fplgtr282/chapter_06_fpl_gtr282.pdf",
     "published": "2021"
    }
   ]
  },
  {
   "id": "C11",
   "claim": "Both the standards agency and the Forest Products Laboratory record what a nominal two-by-four actually measures: a dry piece is surfaced to one and a half by three and a half inches.",
   "status": "verified",
   "quote": "2 by 4 is surfaced to 38.1 mm by 88.9 mm",
   "sources": [
    {
     "publisher": "National Institute of Standards and Technology, U.S. Department of Commerce",
     "title": "Voluntary Product Standard PS 20-25, American Softwood Lumber Standard",
     "url": "https://www.nist.gov/document/ps-20-25-final",
     "published": "2025-01"
    },
    {
     "publisher": "U.S. Department of Agriculture, Forest Service, Forest Products Laboratory",
     "title": "Commercial Lumber, Round Timbers, and Ties, chapter 6 of the Wood Handbook (General Technical Report FPL-GTR-282)",
     "url": "https://www.fpl.fs.usda.gov/documnts/fplgtr/fplgtr282/chapter_06_fpl_gtr282.pdf",
     "published": "2021"
    }
   ]
  },
  {
   "id": "C12",
   "claim": "The Residential Code of Ohio limits what may be cut out of a wall stud: a notch may take no more than 25 percent of the width of a stud in an exterior wall or bearing partition and 40 percent in a nonbearing partition, and a bored hole no more than 60 percent, kept five eighths of an inch from the edge and never in the same place as a notch.",
   "status": "single",
   "quote": "cut or notched to a depth not exceeding 25 percent of its width",
   "sources": [
    {
     "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
     "title": "Rule 4101:8-6-01, Wall construction (Residential Code of Ohio)",
     "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-6-01",
     "published": "2019-07-01"
    }
   ]
  },
  {
   "id": "C13",
   "claim": "Where piping or ductwork cuts more than half the width of a top plate, Ohio requires a galvanized metal tie at least 0.054 inch thick and one and a half inches wide, fastened with eight 10d nails each side and running at least six inches past the opening.",
   "status": "single",
   "quote": "a galvanized metal tie not less than 0.054 inch thick",
   "sources": [
    {
     "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
     "title": "Rule 4101:8-6-01, Wall construction (Residential Code of Ohio)",
     "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-6-01",
     "published": "2019-07-01"
    }
   ]
  },
  {
   "id": "C14",
   "claim": "The federal rehabilitation guide dates plywood wall sheathing to the middle of the 1960s and says that until then the dominant wall sheathing was one-by-three and one-by-four boards, usually nailed diagonally to the studs.",
   "status": "single",
   "quote": "Until the mid-1960s, when plywood was introduced",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 2: Exterior Walls",
     "url": "https://www.huduser.gov/portal/Publications/PDF/walls.pdf",
     "published": "1999-08"
    }
   ]
  },
  {
   "id": "C15",
   "claim": "The same guide dates oriented strand board's introduction as sheathing to the early 1980s.",
   "status": "single",
   "quote": "Introduced in the early 1980s, OSB",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 2: Exterior Walls",
     "url": "https://www.huduser.gov/portal/Publications/PDF/walls.pdf",
     "published": "1999-08"
    }
   ]
  },
  {
   "id": "C16",
   "claim": "The rehabilitation guide dates vinyl siding's introduction to the 1960s and, writing in 1999, called it the leading wall cladding material for siding.",
   "status": "single",
   "quote": "Introduced in the 1960s, vinyl siding has become the leading wall cladding material",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 2: Exterior Walls",
     "url": "https://www.huduser.gov/portal/Publications/PDF/walls.pdf",
     "published": "1999-08"
    }
   ]
  },
  {
   "id": "C17",
   "claim": "The same guide says aluminum and steel siding gained great popularity in the 1950s and 1960s as a way of covering old siding, and that by 1999 metal siding was about one percent of the new siding market.",
   "status": "single",
   "quote": "Aluminum and steel siding gained great popularity in the 1950s and 1960s",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 2: Exterior Walls",
     "url": "https://www.huduser.gov/portal/Publications/PDF/walls.pdf",
     "published": "1999-08"
    }
   ]
  },
  {
   "id": "C18",
   "claim": "The guide separates two materials that look alike: fiber cement siding in its present form was introduced in the late 1980s, while asbestos-cement siding was used through much of the twentieth century until the use of asbestos was discontinued in the 1970s.",
   "status": "single",
   "quote": "a relative newcomer to the U.S. homebuilding market, having been introduced",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 2: Exterior Walls",
     "url": "https://www.huduser.gov/portal/Publications/PDF/walls.pdf",
     "published": "1999-08"
    }
   ]
  },
  {
   "id": "C19",
   "claim": "The National Park Service's brief on aluminum and vinyl siding, published in 1984, was rescinded in October 2023; the agency says its information and guidance no longer represent best historic preservation practices.",
   "status": "single",
   "quote": "Rescinded October 2023; information and guidance no longer represent best historic preservation practices",
   "sources": [
    {
     "publisher": "National Park Service",
     "title": "Preservation Briefs (index of the series), Technical Preservation Services",
     "url": "https://www.nps.gov/orgs/1739/preservation-briefs.htm",
     "published": "undated"
    }
   ]
  },
  {
   "id": "C20",
   "claim": "The Census Bureau's regional series shows the change in one lifetime: of new single-family houses completed in the Midwest, 43 percent had wood as the primary exterior wall material in 1973 and 23 percent brick, against 64 percent vinyl siding, 16 percent wood, 12 percent fiber cement and 4 percent brick in 2025.",
   "status": "single",
   "quote": "Primary Type of Exterior Wall Material of New Single-Family Houses Completed",
   "sources": [
    {
     "publisher": "U.S. Census Bureau",
     "title": "Characteristics of New Housing: Primary Type of Exterior Wall Material of New Single-Family Houses Completed",
     "url": "https://www.census.gov/construction/chars/xls/exwallmat_cust.xls",
     "published": "2026"
    }
   ]
  },
  {
   "id": "C21",
   "claim": "The Brick Industry Association describes the modern anchored brick veneer wall as a nominal three or four inch brick wythe tied to a wood frame with corrosion-resistant anchors, carried vertically by the foundation, with an air space of at least one inch, flashing and weeps.",
   "status": "single",
   "quote": "Maintain a minimum 1 in. (25 mm) air space",
   "sources": [
    {
     "publisher": "Brick Industry Association",
     "title": "Technical Notes on Brick Construction 28: Brick Veneer/Wood Stud Walls",
     "url": "https://www.gobrick.com/media/file/28-brick-veneer-wood-stud-walls.pdf",
     "published": "2012-11"
    }
   ]
  },
  {
   "id": "C22",
   "claim": "The National Park Service says plaster was the wall surface chosen for nearly all buildings until the 1930s or 1940s, that plasterers used lime plaster until the end of the nineteenth century, and that gypsum began to be used as a plastering material around 1900.",
   "status": "single",
   "quote": "the wall surface chosen for nearly all buildings until the 1930s or 40s",
   "sources": [
    {
     "publisher": "National Park Service",
     "title": "Preservation Brief 21: Repairing Historic Flat Plaster Walls and Ceilings",
     "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-21-flat-plaster.pdf",
     "published": "1989-10"
    }
   ]
  },
  {
   "id": "C23",
   "claim": "The same brief dates the three plaster bases: wood lath, metal lath patented in England in 1797 and used in parts of the United States toward the end of the nineteenth century, and rock lath, in use as early as 1900 and used almost exclusively in residential plastering by the late 1930s.",
   "status": "single",
   "quote": "By the late 1930s, rock lath was used almost exclusively in residential plastering",
   "sources": [
    {
     "publisher": "National Park Service",
     "title": "Preservation Brief 21: Repairing Historic Flat Plaster Walls and Ceilings",
     "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-21-flat-plaster.pdf",
     "published": "1989-10"
    }
   ]
  },
  {
   "id": "C24",
   "claim": "The federal rehabilitation guide dates the change to gypsum board later, saying the dominant wall material has been plaster or, since the 1960s, gypsum board.",
   "status": "single",
   "quote": "the dominant wall material has been plaster or, since the 1960s, gypsum board",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 5: Partitions, Ceilings, Floors and Stairs",
     "url": "https://www.huduser.gov/portal/Publications/PDF/part.pdf",
     "published": "1999-11"
    }
   ]
  },
  {
   "id": "C25",
   "claim": "Plaster is not a repealed method in Ohio: the current Residential Code of Ohio still prints a plaster thickness table naming expanded metal lath, wire lath and gypsum lath.",
   "status": "single",
   "quote": "THICKNESS OF PLASTER",
   "sources": [
    {
     "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
     "title": "Rule 4101:8-7-01, Wall covering (Residential Code of Ohio)",
     "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-7-01",
     "published": "2019-07-01"
    }
   ]
  },
  {
   "id": "C26",
   "claim": "The Agriculture Department's 1955 house-building handbook describes the bathroom wall behind the tile as it was then built: expanded metal lath over a paper backing around the tub recess, studs covered with 15-pound asphalt-saturated felt laid shingle style, and a scratch coat of portland cement plaster at least five eighths of an inch thick and integrally waterproofed.",
   "status": "single",
   "quote": "Expanded-metal lath applied around a tub recess for ceramic-tile application",
   "sources": [
    {
     "publisher": "U.S. Department of Agriculture, Forest Service, Forest Products Laboratory",
     "title": "Wood-Frame House Construction, Agriculture Handbook No. 73",
     "url": "https://archive.org/details/WoodFrameHouseConstruction",
     "published": "1955-02"
    }
   ]
  },
  {
   "id": "C27",
   "claim": "The same handbook shows what went on a bathroom wall where there was no tile: a waterproof-finish plaster, which it names as Keene's cement, especially in showers and tub recesses.",
   "status": "single",
   "quote": "Waterproof-finish wall materials (Keene's cement) are available and should be used in bathrooms",
   "sources": [
    {
     "publisher": "U.S. Department of Agriculture, Forest Service, Forest Products Laboratory",
     "title": "Wood-Frame House Construction, Agriculture Handbook No. 73",
     "url": "https://archive.org/details/WoodFrameHouseConstruction",
     "published": "1955-02"
    }
   ]
  },
  {
   "id": "C28",
   "claim": "The National Park Service records what the tile itself was in that period: larger rectangular white glazed tiles for bathroom walls and wainscots, alongside the small white unglazed tiles sold for floors, with colored tile also popular in bathrooms.",
   "status": "single",
   "quote": "glazed tiles were used for bathroom walls or wainscotting",
   "sources": [
    {
     "publisher": "National Park Service",
     "title": "Preservation Brief 40: Preserving Historic Ceramic Tile Floors",
     "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-40-ceramic-tile-floors.pdf",
     "published": "1996"
    }
   ]
  },
  {
   "id": "C29",
   "claim": "The federal rehabilitation guide's kitchens and baths volume is blunt about gypsum board behind tile: even water-resistant green board will not dry out as quickly as cement-based backer board, and for rehabilitation work it tells the reader to use cement-based backer board.",
   "status": "single",
   "quote": "will not dry out as quickly as cement-based backer board",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 6: Kitchens and Baths",
     "url": "https://www.huduser.gov/portal/Publications/PDF/kitchen.pdf",
     "published": "1999-09"
    }
   ]
  },
  {
   "id": "C30",
   "claim": "The Residential Code of Ohio writes its limit on water-resistant gypsum board as a condition rather than a room: it may not be used where there will be direct exposure to water or in areas subject to continuous high humidity, and it may not be installed over a Class I or II vapor retarder in a shower or tub compartment.",
   "status": "single",
   "quote": "shall not be used where there will be direct exposure to water",
   "sources": [
    {
     "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
     "title": "Rule 4101:8-7-01, Wall covering (Residential Code of Ohio)",
     "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-7-01",
     "published": "2019-07-01"
    }
   ]
  },
  {
   "id": "C31",
   "claim": "What may go behind wall tile in a tub or shower is instead a short list: Ohio requires backers there to be one of four materials named in Table 702.4.2, and ordinary water-resistant gypsum board is not among them.",
   "status": "single",
   "quote": "Materials used as backers for wall tile in tub and shower areas",
   "sources": [
    {
     "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
     "title": "Rule 4101:8-7-01, Wall covering (Residential Code of Ohio)",
     "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-7-01",
     "published": "2019-07-01"
    }
   ]
  },
  {
   "id": "C32",
   "claim": "For a modern tiled shower built on a waterproof membrane, the Tile Council of North America says its Handbook does not name the backing: it leaves the choice of membrane and backer board combination to the manufacturers and the design professional.",
   "status": "single",
   "quote": "leaves the determination of a suitable membrane/backer board combination up to the",
   "sources": [
    {
     "publisher": "Tile Council of North America",
     "title": "Frequently Asked Questions: Showers",
     "url": "https://tcnatile.com/resource-center/faq/showers/",
     "published": "undated"
    }
   ]
  },
  {
   "id": "C33",
   "claim": "Two federal sources agree on when asphalt shingles arrived: the National Park Service says asphalt shingles and roll roofing were used in the 1890s, and the rehabilitation guide says they entered the roofing market in the late 1800s as a by-product of making tar and asphalt-impregnated felts.",
   "status": "verified",
   "quote": "Asphalt shingles and roll roofing were used in the 1890s",
   "sources": [
    {
     "publisher": "National Park Service",
     "title": "Preservation Brief 4: Roofing for Historic Buildings",
     "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-04-roofing.pdf",
     "published": "1978"
    },
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 3: Roofs",
     "url": "https://www.huduser.gov/portal/Publications/PDF/roofs.pdf",
     "published": "1999-03"
    }
   ]
  },
  {
   "id": "C34",
   "claim": "The rehabilitation guide dates the mat inside the shingle: organic cellulose fiber from the early 1940s to the late 1970s, and inorganic fiberglass mat dominant since the late 1970s.",
   "status": "single",
   "quote": "the dominant base material since the late 1970s has been inorganic",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 3: Roofs",
     "url": "https://www.huduser.gov/portal/Publications/PDF/roofs.pdf",
     "published": "1999-03"
    }
   ]
  },
  {
   "id": "C35",
   "claim": "The same volume says roof sheathing in houses built before the 1950s is typically one-inch boards, and that houses built since the middle of that decade most likely have plywood, particleboard or oriented strand board.",
   "status": "single",
   "quote": "Roof sheathing in older houses (before the 1950s) is typically 1x boards",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 3: Roofs",
     "url": "https://www.huduser.gov/portal/Publications/PDF/roofs.pdf",
     "published": "1999-03"
    }
   ]
  },
  {
   "id": "C36",
   "claim": "The National Park Service put the heat transfer of a single-glazed wooden window between 0.88 and 0.99 and said adding a storm window should bring that to between 0.44 and 0.49.",
   "status": "single",
   "quote": "the U-values for single glazed wooden windows range from 0.88 to 0.99",
   "sources": [
    {
     "publisher": "National Park Service",
     "title": "Preservation Brief 9: The Repair of Historic Wooden Windows",
     "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-09-wood-windows.pdf",
     "published": "1981"
    }
   ]
  },
  {
   "id": "C37",
   "claim": "Ohio's residential energy table sets what a new house in the state's climate zone 5 must reach: a maximum window U-factor of 0.30, ceiling R-49, a wood frame wall at R-20 or R-13 plus R-5 continuous, a floor at R-30, and a basement wall at R-10 continuous or R-13 in the cavity.",
   "status": "single",
   "quote": "The building thermal envelope shall meet the requirements of Table 1102.1.2",
   "sources": [
    {
     "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
     "title": "Rule 4101:8-11-01, Energy efficiency (Residential Code of Ohio)",
     "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-11-01",
     "published": "2019-07-01"
    }
   ]
  },
  {
   "id": "C38",
   "claim": "The Agriculture Department's 1955 handbook shows insulation as a settled product by then, describing blanket and batt insulation of wood or vegetable fibers or mineral wool and poured or blown fill, and saying fill was used in the side walls of existing houses that had not been insulated when built.",
   "status": "single",
   "quote": "It is also used in side walls of existing houses that were not insulated",
   "sources": [
    {
     "publisher": "U.S. Department of Agriculture, Forest Service, Forest Products Laboratory",
     "title": "Wood-Frame House Construction, Agriculture Handbook No. 73",
     "url": "https://archive.org/details/WoodFrameHouseConstruction",
     "published": "1955-02"
    }
   ]
  },
  {
   "id": "C39",
   "claim": "The National Park Service states the trade-off plainly: an uninsulated old wood building leaks more air than a modern one, which makes it less efficient but helps dry the wall out, and it says the effect of adding insulation to a wood-frame wall is hard to predict.",
   "status": "single",
   "quote": "Un-insulated historic wood buildings have a higher rate of air",
   "sources": [
    {
     "publisher": "National Park Service",
     "title": "Preservation Brief 3: Improving Energy Efficiency in Historic Buildings",
     "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-03-energy-efficiency.pdf",
     "published": "2011"
    }
   ]
  },
  {
   "id": "C40",
   "claim": "The rehabilitation guide dates gas in houses to the middle of the 1880s, with lighting and cooking first and space and water heating added later, and says that as electricity reached houses forced-air systems replaced most of the gravity systems that had moved heated air by natural convection.",
   "status": "single",
   "quote": "has been used in houses since the mid-1880s",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 8: HVAC/Plumbing",
     "url": "https://www.huduser.gov/portal/Publications/PDF/hvac.pdf",
     "published": "1999-08"
    }
   ]
  },
  {
   "id": "C41",
   "claim": "In the Census Bureau's series, 75 percent of new single-family houses completed in the Midwest in 1973 had a forced-air furnace, and 88 percent in 2025.",
   "status": "single",
   "quote": "Type of Heating System Used in New Single-Family Houses Completed",
   "sources": [
    {
     "publisher": "U.S. Census Bureau",
     "title": "Characteristics of New Housing: Type of Heating System Used in New Single-Family Houses Completed",
     "url": "https://www.census.gov/construction/chars/xls/heatsystem_cust.xls",
     "published": "2026"
    }
   ]
  },
  {
   "id": "C42",
   "claim": "The Census Bureau's regional series puts central air conditioning in 35 percent of new single-family houses completed in the Midwest in 1973 and 96 percent in 2025.",
   "status": "single",
   "quote": "Presence of Air-Conditioning in New Single-Family Houses Completed",
   "sources": [
    {
     "publisher": "U.S. Census Bureau",
     "title": "Characteristics of New Housing: Presence of Air-Conditioning in New Single-Family Houses Completed",
     "url": "https://www.census.gov/construction/chars/xls/aircond_cust.xls",
     "published": "2026"
    },
    {
     "publisher": "U.S. Census Bureau",
     "title": "Survey of Construction: Definitions",
     "url": "https://www.census.gov/construction/soc/definitions.html",
     "published": "undated"
    }
   ]
  },
  {
   "id": "C43",
   "claim": "The Ohio Geological Survey says the Devonian-age Columbus and Delaware Limestones were used extensively for home building in central Ohio in the early 1800s, and that the Ohio Statehouse, completed in 1861, extensively used Columbus Limestone.",
   "status": "single",
   "quote": "Columbus and Delaware Limestones were used extensively for home building in central Ohio",
   "sources": [
    {
     "publisher": "Ohio Department of Natural Resources, Division of Geological Survey",
     "title": "GeoFacts No. 32, Dimension Stone in Ohio",
     "url": "https://dam.assets.ohio.gov/image/upload/ohiodnr.gov/documents/geology/GF32_Stucker_2023.pdf",
     "published": "2023"
    }
   ]
  },
  {
   "id": "C44",
   "claim": "The National Park Service says that in the last quarter of the nineteenth century Zanesville, Ohio was the largest center for pottery and tile-making in the world, and that the American Encaustic Tiling Company, established there in 1876, was the largest tile company in the world in the early 1930s before closing about 1935.",
   "status": "single",
   "quote": "was the largest center for pottery and tile-making in the world",
   "sources": [
    {
     "publisher": "National Park Service",
     "title": "Preservation Brief 40: Preserving Historic Ceramic Tile Floors",
     "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-40-ceramic-tile-floors.pdf",
     "published": "1996"
    }
   ]
  },
  {
   "id": "C45",
   "claim": "Owens Corning's own annual report to the Securities and Exchange Commission says the company was founded in 1938 and is based in Toledo, Ohio, and describes insulation as one of its three businesses alongside roofing and doors.",
   "status": "single",
   "quote": "Founded in 1938 and based in Toledo, Ohio",
   "sources": [
    {
     "publisher": "U.S. Securities and Exchange Commission (Owens Corning, Form 10-K)",
     "title": "Owens Corning Annual Report on Form 10-K for the fiscal year ended December 31, 2025",
     "url": "https://www.sec.gov/Archives/edgar/data/1370946/000137094626000067/oc-20251231.htm",
     "published": "2026-02-25"
    }
   ]
  },
  {
   "id": "C46",
   "claim": "A National Register nomination describes what a Lustron house is made of: a one-story side-gabled ranch on a concrete slab, clad outside in gray porcelain-enameled steel panels two feet square, roofed in porcelain-enameled tile-like shingles the form lists as steel, lined inside with porcelain-enameled steel panels two feet by eight, and fitted with aluminum casement windows.",
   "status": "single",
   "quote": "The exterior porcelain-enameled steel panels are gray and measure two-feet square",
   "sources": [
    {
     "publisher": "National Park Service, National Register of Historic Places",
     "title": "National Register of Historic Places Registration Form: 711 Ninth Avenue Lustron House, Albany, Dougherty County, Georgia",
     "url": "https://npgallery.nps.gov/NRHP/GetAsset/b46b528a-546b-43da-a129-28084ea25e6e",
     "published": "undated"
    }
   ]
  },
  {
   "id": "C47",
   "claim": "The Ohio Board of Building Standards says the Ohio legislature first authorized construction regulation in 1911, and that in 1955 it authorized adopting a state building code by administrative rather than legislative procedure, naming the Board as the agency.",
   "status": "single",
   "quote": "The Ohio legislature first authorized construction regulation in 1911",
   "sources": [
    {
     "publisher": "Ohio Board of Building Standards, Ohio Department of Commerce",
     "title": "History of BBS",
     "url": "https://dam.assets.ohio.gov/image/upload/com.ohio.gov/documents/bbst_BBSAbout.pdf",
     "published": "undated"
    }
   ]
  },
  {
   "id": "C48",
   "claim": "The same history records what that state code did not cover: the legislature specifically exempted one-, two- and three-family dwellings and agricultural buildings.",
   "status": "single",
   "quote": "The state legislature specifically exempted 1-, 2-, 3-family dwellings and agricultural buildings",
   "sources": [
    {
     "publisher": "Ohio Board of Building Standards, Ohio Department of Commerce",
     "title": "History of BBS",
     "url": "https://dam.assets.ohio.gov/image/upload/com.ohio.gov/documents/bbst_BBSAbout.pdf",
     "published": "undated"
    }
   ]
  },
  {
   "id": "C49",
   "claim": "The Board adopted the BOCA model codes as the Ohio Basic Building Code on September 29, 1978, with an effective date of July 1, 1979.",
   "status": "single",
   "quote": "the Board adopted the BOCA codes as the Ohio Basic Building Codes",
   "sources": [
    {
     "publisher": "Ohio Board of Building Standards, Ohio Department of Commerce",
     "title": "History of BBS",
     "url": "https://dam.assets.ohio.gov/image/upload/com.ohio.gov/documents/bbst_BBSAbout.pdf",
     "published": "undated"
    }
   ]
  },
  {
   "id": "C50",
   "claim": "Ohio's separate residential code for one-, two- and three-family dwellings is recent: the administration rule of the Residential Code of Ohio gives May 27, 2006 as its earliest prior effective date.",
   "status": "single",
   "quote": "Prior Effective Dates:",
   "sources": [
    {
     "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
     "title": "Rule 4101:8-1-01, Administration (Residential Code of Ohio)",
     "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-1-01",
     "published": "2019-07-01"
    }
   ]
  },
  {
   "id": "C51",
   "claim": "The Forest Products Laboratory's own 1964 history of the lumber standard records where the modern two-by-four came from: under the 1953 standard green and dry lumber could be dressed to the same sizes, and in December 1961 the industry's grade committee agreed to leave the widths alone and cut the standard dry thickness of two-inch lumber from 1-5/8 to 1-1/2 inches.",
   "status": "single",
   "quote": "the standard dry thickness be reduced from 1-5/8 to 1-1/2 inches",
   "sources": [
    {
     "publisher": "U.S. Department of Agriculture, Forest Service, Forest Products Laboratory",
     "title": "History of Yard Lumber Size Standards",
     "url": "https://archive.org/details/CAT10508210",
     "published": "1964-09"
    }
   ]
  },
  {
   "id": "C52",
   "claim": "The federal rehabilitation guide's foundation volume says the great majority of residential foundations are either concrete or concrete block, that concrete dominates in most areas but concrete block is more common in the industrialized states of the Northeast and the Northcentral United States, and that foundations of houses built more than sixty years before it was written are often made of stone.",
   "status": "single",
   "quote": "The great majority of residential foundations are either concrete or concrete block",
   "sources": [
    {
     "publisher": "U.S. Department of Housing and Urban Development",
     "title": "The Rehab Guide, Volume 1: Foundations",
     "url": "https://www.huduser.gov/portal/Publications/PDF/found.pdf",
     "published": "1997-06"
    }
   ]
  }
 ],
 "conflicts": [
  {
   "claim_id": "C14",
   "a": "Plywood wall sheathing arrived in the mid-1960s; until then wall sheathing was 1x3 and 1x4 boards",
   "a_source": "S3 (HUD Rehab Guide Volume 2, Exterior Walls, 1999)",
   "b": "Plywood floors began to replace board sheathing in the early 1940s (wave eight, floors sheet C3); plywood roof sheathing appears in houses built since the mid 1950s (S6, HUD Volume 3)",
   "b_source": "HUD Rehab Guide Volumes 5 and 3, the same publisher",
   "printed": "print all three, each tied to its part of the house. One agency gives three dates because plywood reached floors, then roofs, then walls. A page that prints one date for 'plywood' will be wrong about two of them."
  },
  {
   "claim_id": "C24",
   "a": "Plaster was the wall surface for nearly all buildings until the 1930s or 1940s",
   "a_source": "S14 (National Park Service, Preservation Brief 21, 1989)",
   "b": "The dominant wall material has been plaster or, since the 1960s, gypsum board",
   "b_source": "S4 (HUD Rehab Guide Volume 5, 1999)",
   "printed": "print both, attributed. The Park Service is describing when plaster stopped being the default and HUD when gypsum board became dominant; the twenty-year gap is real and covers the rock-lath-and-plaster houses of the 1940s and 1950s, which are neither. A Central Ohio house of that period may have either."
  },
  {
   "claim_id": "C5",
   "a": "The Midwest has the highest share of new houses with basements",
   "a_source": "the brief's premise, and the usual telling",
   "b": "The Northeast is higher in 1971 (80 against 72 percent) and in 2025 (53 against 50); the Midwest leads in many middle years, such as 1984 and 2014",
   "b_source": "S19 (Census Bureau foundation series)",
   "printed": "print neither superlative. Give the Midwest figures against the national ones, which is the comparison a homeowner is actually asking about, and leave the ranking out."
  },
  {
   "claim_id": "C10",
   "a": "The 1924 lumber standard was revised in 1925, 1926, 1929, 1939 and 1953",
   "a_source": "S18 (NIST, Voluntary Product Standard PS 20-25, Appendix D3)",
   "b": "The 1924 standard 'was revised in 1926, 1928, 1939, and 1953'",
   "b_source": "S39 (Forest Products Laboratory, History of Yard Lumber Size Standards, 1964)",
   "printed": "print neither list. Two federal agencies give different intermediate revision years for the same standard, and nothing on this page turns on them. Print 1924 for the first national size standard and 1970 for the dry-and-green split, both of which the two sources agree on, and the December 1961 agreement from C51."
  }
 ],
 "sources": [
  {
   "id": "S1",
   "publisher": "U.S. Department of Housing and Urban Development",
   "title": "The Rehab Guide, Volume 1: Foundations",
   "url": "https://www.huduser.gov/portal/Publications/PDF/found.pdf",
   "published": "1997-06"
  },
  {
   "id": "S2",
   "publisher": "National Park Service",
   "title": "Preservation Brief 2: Repointing Mortar Joints in Historic Masonry Buildings",
   "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-02-repointing.pdf",
   "published": "1998"
  },
  {
   "id": "S3",
   "publisher": "U.S. Department of Housing and Urban Development",
   "title": "The Rehab Guide, Volume 2: Exterior Walls",
   "url": "https://www.huduser.gov/portal/Publications/PDF/walls.pdf",
   "published": "1999-08"
  },
  {
   "id": "S4",
   "publisher": "U.S. Department of Housing and Urban Development",
   "title": "The Rehab Guide, Volume 5: Partitions, Ceilings, Floors and Stairs",
   "url": "https://www.huduser.gov/portal/Publications/PDF/part.pdf",
   "published": "1999-11"
  },
  {
   "id": "S5",
   "publisher": "U.S. Department of Housing and Urban Development",
   "title": "The Rehab Guide, Volume 6: Kitchens and Baths",
   "url": "https://www.huduser.gov/portal/Publications/PDF/kitchen.pdf",
   "published": "1999-09"
  },
  {
   "id": "S6",
   "publisher": "U.S. Department of Housing and Urban Development",
   "title": "The Rehab Guide, Volume 3: Roofs",
   "url": "https://www.huduser.gov/portal/Publications/PDF/roofs.pdf",
   "published": "1999-03"
  },
  {
   "id": "S7",
   "publisher": "U.S. Department of Housing and Urban Development",
   "title": "The Rehab Guide, Volume 8: HVAC/Plumbing",
   "url": "https://www.huduser.gov/portal/Publications/PDF/hvac.pdf",
   "published": "1999-08"
  },
  {
   "id": "S8",
   "publisher": "National Park Service",
   "title": "Preservation Brief 3: Improving Energy Efficiency in Historic Buildings",
   "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-03-energy-efficiency.pdf",
   "published": "2011"
  },
  {
   "id": "S9",
   "publisher": "National Park Service",
   "title": "Preservation Brief 4: Roofing for Historic Buildings",
   "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-04-roofing.pdf",
   "published": "1978"
  },
  {
   "id": "S10",
   "publisher": "National Park Service",
   "title": "Preservation Briefs (index of the series), Technical Preservation Services",
   "url": "https://www.nps.gov/orgs/1739/preservation-briefs.htm",
   "published": "undated"
  },
  {
   "id": "S11",
   "publisher": "National Park Service",
   "title": "Preservation Brief 9: The Repair of Historic Wooden Windows",
   "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-09-wood-windows.pdf",
   "published": "1981"
  },
  {
   "id": "S12",
   "publisher": "National Park Service",
   "title": "Preservation Brief 15: Preservation of Historic Concrete",
   "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-15-concrete.pdf",
   "published": "2007"
  },
  {
   "id": "S13",
   "publisher": "National Park Service",
   "title": "Preservation Brief 16: The Use of Substitute Materials on Historic Building Exteriors",
   "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-16-substitute-materials-2023.pdf",
   "published": "2023"
  },
  {
   "id": "S14",
   "publisher": "National Park Service",
   "title": "Preservation Brief 21: Repairing Historic Flat Plaster Walls and Ceilings",
   "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-21-flat-plaster.pdf",
   "published": "1989-10"
  },
  {
   "id": "S15",
   "publisher": "National Park Service",
   "title": "Preservation Brief 40: Preserving Historic Ceramic Tile Floors",
   "url": "https://www.nps.gov/orgs/1739/upload/preservation-brief-40-ceramic-tile-floors.pdf",
   "published": "1996"
  },
  {
   "id": "S16",
   "publisher": "U.S. Department of Agriculture, Forest Service, Forest Products Laboratory",
   "title": "Wood-Frame House Construction, Agriculture Handbook No. 73",
   "url": "https://archive.org/details/WoodFrameHouseConstruction",
   "published": "1955-02"
  },
  {
   "id": "S17",
   "publisher": "U.S. Department of Agriculture, Forest Service, Forest Products Laboratory",
   "title": "Commercial Lumber, Round Timbers, and Ties, chapter 6 of the Wood Handbook (General Technical Report FPL-GTR-282)",
   "url": "https://www.fpl.fs.usda.gov/documnts/fplgtr/fplgtr282/chapter_06_fpl_gtr282.pdf",
   "published": "2021"
  },
  {
   "id": "S18",
   "publisher": "National Institute of Standards and Technology, U.S. Department of Commerce",
   "title": "Voluntary Product Standard PS 20-25, American Softwood Lumber Standard",
   "url": "https://www.nist.gov/document/ps-20-25-final",
   "published": "2025-01"
  },
  {
   "id": "S19",
   "publisher": "U.S. Census Bureau",
   "title": "Characteristics of New Housing: Type of Foundation in New Single-Family Houses Completed",
   "url": "https://www.census.gov/construction/chars/xls/foundation_cust.xls",
   "published": "2026"
  },
  {
   "id": "S20",
   "publisher": "U.S. Census Bureau",
   "title": "Characteristics of New Housing: Primary Type of Exterior Wall Material of New Single-Family Houses Completed",
   "url": "https://www.census.gov/construction/chars/xls/exwallmat_cust.xls",
   "published": "2026"
  },
  {
   "id": "S21",
   "publisher": "U.S. Census Bureau",
   "title": "Characteristics of New Housing: Presence of Air-Conditioning in New Single-Family Houses Completed",
   "url": "https://www.census.gov/construction/chars/xls/aircond_cust.xls",
   "published": "2026"
  },
  {
   "id": "S22",
   "publisher": "U.S. Census Bureau",
   "title": "Characteristics of New Housing: Type of Heating System Used in New Single-Family Houses Completed",
   "url": "https://www.census.gov/construction/chars/xls/heatsystem_cust.xls",
   "published": "2026"
  },
  {
   "id": "S25",
   "publisher": "U.S. Census Bureau",
   "title": "Survey of Construction: Definitions",
   "url": "https://www.census.gov/construction/soc/definitions.html",
   "published": "undated"
  },
  {
   "id": "S26",
   "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
   "title": "Rule 4101:8-7-01, Wall covering (Residential Code of Ohio)",
   "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-7-01",
   "published": "2019-07-01"
  },
  {
   "id": "S27",
   "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
   "title": "Rule 4101:8-6-01, Wall construction (Residential Code of Ohio)",
   "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-6-01",
   "published": "2019-07-01"
  },
  {
   "id": "S28",
   "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
   "title": "Rule 4101:8-4-01, Foundations (Residential Code of Ohio)",
   "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-4-01",
   "published": "2019-07-01"
  },
  {
   "id": "S29",
   "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
   "title": "Rule 4101:8-11-01, Energy efficiency (Residential Code of Ohio)",
   "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-11-01",
   "published": "2019-07-01"
  },
  {
   "id": "S30",
   "publisher": "Ohio Administrative Code, Ohio Laws (codes.ohio.gov)",
   "title": "Rule 4101:8-1-01, Administration (Residential Code of Ohio)",
   "url": "https://codes.ohio.gov/ohio-administrative-code/rule-4101:8-1-01",
   "published": "2019-07-01"
  },
  {
   "id": "S31",
   "publisher": "City of Columbus, Department of Building and Zoning Services",
   "title": "Construction Industry Communication #09, Climatic and Geographic Design Criteria per Section R301.2 of the Residential Code of Ohio",
   "url": "https://www.columbus.gov/files/sharedassets/city/v/2/building-and-zoning/cics/cic-09-climatic-geographic-design-2026.pdf",
   "published": "2006-07-13"
  },
  {
   "id": "S32",
   "publisher": "Ohio Board of Building Standards, Ohio Department of Commerce",
   "title": "History of BBS",
   "url": "https://dam.assets.ohio.gov/image/upload/com.ohio.gov/documents/bbst_BBSAbout.pdf",
   "published": "undated"
  },
  {
   "id": "S33",
   "publisher": "Ohio Department of Natural Resources, Division of Geological Survey",
   "title": "GeoFacts No. 32, Dimension Stone in Ohio",
   "url": "https://dam.assets.ohio.gov/image/upload/ohiodnr.gov/documents/geology/GF32_Stucker_2023.pdf",
   "published": "2023"
  },
  {
   "id": "S34",
   "publisher": "National Park Service, National Register of Historic Places",
   "title": "National Register of Historic Places Registration Form: 711 Ninth Avenue Lustron House, Albany, Dougherty County, Georgia",
   "url": "https://npgallery.nps.gov/NRHP/GetAsset/b46b528a-546b-43da-a129-28084ea25e6e",
   "published": "undated"
  },
  {
   "id": "S35",
   "publisher": "Brick Industry Association",
   "title": "Technical Notes on Brick Construction 28: Brick Veneer/Wood Stud Walls",
   "url": "https://www.gobrick.com/media/file/28-brick-veneer-wood-stud-walls.pdf",
   "published": "2012-11"
  },
  {
   "id": "S37",
   "publisher": "Tile Council of North America",
   "title": "Frequently Asked Questions: Showers",
   "url": "https://tcnatile.com/resource-center/faq/showers/",
   "published": "undated"
  },
  {
   "id": "S38",
   "publisher": "U.S. Securities and Exchange Commission (Owens Corning, Form 10-K)",
   "title": "Owens Corning Annual Report on Form 10-K for the fiscal year ended December 31, 2025",
   "url": "https://www.sec.gov/Archives/edgar/data/1370946/000137094626000067/oc-20251231.htm",
   "published": "2026-02-25"
  },
  {
   "id": "S39",
   "publisher": "U.S. Department of Agriculture, Forest Service, Forest Products Laboratory",
   "title": "History of Yard Lumber Size Standards",
   "url": "https://archive.org/details/CAT10508210",
   "published": "1964-09"
  }
 ]
}