How to Determine The age of a building - Visual & Other Clues - A Home Inspection Guide to Building Age
InspectAPedia® -
How to determine the age of a building
Building component age: construction materials, methods, including hardware, saw cuts, and other details can help determine when a building was constructed or when it was modified.
Our site offers impartial, unbiased advice without conflicts of interest.
We will block advertisements which we discover or readers inform us are associated with bad business practices,
false-advertising, or junk science. Our contact info is at
InspectAPedia.com/appointment.htm.
Here we provide a photo guide to determining the age of a building by examination of the architectural style of construction or the building materials and components that were used in the structure. The age of a building can be determined quite accurately by documentation, but when documents are not readily
available, visual clues such as those available during a professional home inspection can still determine when a house was built by examining its components, building materials, even nails, fasteners, and types of saw cuts on lumber. Our page top photo shows a Mid-Victorian multi-floor structure built in Hudson, NY, USA ca 1874. The entire building exterior facade is made of cast iron, including the window parapets and sills and the faux stone exterior walls and corner quoins.
Here we list some helpful
clues to answer the question "how old is the house?" and we provide photographs of key visual
clues useful for determining the age of a building.
How to Determine The age of a building - A List of Visual and Documentary Clues Provided by a Home Inspection
Visual clues pointed out by a home inspector or available to any careful building inspector
can help indicate the age of a building.
Clues to building age include these examples which we expand and detail in text and articles below:
Architectural style, decorations, trim, building components
Building material types (shiplap siding, cement asbestos shingle siding, aluminum siding, vinyl siding, plywood vs. tongue and groove sheathing, even types of brick.
Building Framing methods,
hand hewn adze marks or even the type of saw cut marks on framing lumber,
Construction fasteners, nails, screws, the use of treenails or pegs
in post and beam framing,
Construction and framing methods such as post and beam, presence or absence of a ridge board,
balloon framing or platform framing,
Roofing nails and screws used,
Mechanical systems and plumbing materials; presence of gas piping, style of fireplace,
Chimney construction, type of mortar used, materials;
Electrical wiring, different wire types and generations of wire, fuses, circuit breakers, panels, etc.
Hardware: window and door hardware, hinges, doorknobs, door pulls, latches
Lumber width and edge finish of wood boards in various uses, interior trim,
and
And many similar details are available to the careful eye.
Keep in mind that even when we can identify specific types of building materials and building methods, precise dating of
the time of construction of a building remains difficult: old building materials were often re-used, so beams, siding, and other
components may appear in a building built later than when the materials were first made.
Also, in the U.S. various
states had machines for making cut nails, screws, and sawmills at different times. For example, New York State was industrialized
earlier than some western or southern states, so machine-made nails appear earlier in New York than elsewhere.
Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
Additional technical contributors & reference sources for this article are listed below.
Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.
Thanks to Alan Carson and Bob Dunlop, Carson Dunlop, Associates, Toronto, for permission to use illustrations from their publication, The Illustrated Home which illustrates construction details and building components. Carson Dunlop provides home inspection education, publications, report writing materials, and home inspection services. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.
Thanks to reader Kathy Bohon for suggesting using various sources of public records to determine the age of a home, 7/30/2009.
Carson Dunlop, Associates, Toronto, have provided us with (and we recommend)
Carson Dunlop Weldon & Associates' Technical Reference Guide to manufacturer's model and serial number information for heating and cooling equipment ($69.00 U.S.). Technical Reference Guide, Carson Dunlop Weldon & Associates, Ltd., 120 Carlton St. Suite 407, Toronto, Ontario, M5A 4K2 Canada, ISBN 1-895585-90-2 165pp.
America's Favorite Homes, mail-order catalogues as a guide to popular early 20th-century houses, Robert Schweitzer, Michael W.R. Davis, 1990, Wayne State University Press ISBN 0814320066 (may be available from Wayne State University Press)
American Plywood Association, APA, "Portland Manufacturing Company, No. 1, a series of monographs on the history of plywood manufacturing",Plywood Pioneers Association, 31 March, 1967, www.apawood.org
Asbestos products and their history and use in various building materials such as asphalt and vinyl flooring includes discussion which draws on Asbestos, Its Industrial Applications, D.V. Rosato, engineering consultant, Newton, MA, Reinhold Publishing, 1959 Library of Congress Catalog Card No.: 59-12535 (out of print).
Building Research Council, BRC, nee Small Homes Council, SHC, School of Architecture, University of Illinois at Urbana-Champaign, brc.arch.uiuc.edu. "The Small Homes Council (our original name) was organized in 1944 during the war at the request of the President of the University of Illinois to consider the role of the university in meeting the demand for housing in the United States. Soldiers would be coming home after the war and would be needing good low-cost housing. ... In 1993, the Council became part of the School of Architecture, and since then has been known as the School of Architecture-Building Research Council. ... The Council's researchers answered many critical questions that would affect the quality of the nation's housing stock.
How could homes be designed and built more efficiently?
What kinds of construction and production techniques worked well and which did not?
How did people use different kinds of spaces in their homes?
What roles did community planning, zoning, and interior design play in how neighborhoods worked?
"
Isham: "An Example of Colonial Paneling", Norman Morrison Isham, The Metropolitan Museum of Art Bulletin, Vol. 6, No. 5 (May, 1911), pp. 112-116, available by JSTOR.
Manufactured & Modular Homes: Modular Building Systems Association, MBSA, modularhousing.com, is a trade association promoting and providing links to contact modular builders in North America. Also see the Manufactured Home Owners Association, MHOAA, at www.mhoaa.us. The Manufactured Home Owners Association of America is a National Organization dedicated to the protection of the rights of all people living in Manufactured Housing in the United States.
Re-Bath, tub lining products is a bath tub relining manufacturer and distributor located in Tempe, Arizona - see rebath.com
Pergo AB, division of Perstorp AB, is a Swedish manufacturer or modern laminate flooring products. Information about the U.S. company can be found at http://www.pergo.com where we obtained historical data used in our discussion of the age of flooring materials in buildings.
Plank House Construction: webslog from plankhouse.wordpress.com/2009/01/25/plank-house-construction/ and where plank houses were built by native Americans, see
Large 1:6 Scale Plank House Construction / P8094228,
Photographer: Mike Meuser
06/12/2007 documented at yurokplankhouse.com where scale model Museum quality Yurok Plank Houses are being sold to raise money for the Blue Creek - Ah Pah Traditional Yurok Village project.
Scott C. LeMarr has provided his file of keys to decode Furnace and Water Heater Age from the data provided on the manufacturer's equipment labels. Mr. LeMarr is
a professional home inspector, Certified Professional Inspector/President,
MASTER Indoor Environmental Specialist (MIES).
Vice President of Wisconsin NACHI. He and his company, Honest Home Inspections, LLC. can be reached at
262-424-5587 or by email to scott@honesthomeinspections.com
Weaver: Beaver Board and Upson Board:
Beaver Board and Upson Board: History and Conservation of Early Wallboard, Shelby Weaver,
APT Bulletin, Vol. 28, No. 2/3 (1997), pp. 71-78, Association for Preservation Technology International (APT), available online at JSTOR.
Photo Examples of Architecture & Style Providing Typical Dates of Construction
While building architectural styles such as "Victorian" continue to be built into the present, the combination
of a recognizable architectural style with an inspection of the building materials which have been used provide
considerable information about the age of a home as well as its history of changes and additions.
See Architecture & Style for photographs of buildings in North America and Europe demonstrating various architectural styles and dates.
Guide to Using Building Records to Help Determine the Age of a Building
Here we discuss and list examples of source of public records that can help determine the age of a building. Because the office where building records are held will vary by name and municipal authority, the exact name and location of building records in your community will vary from those examples shown here.
Sources of public records to assist in determining the age of a building
As suggested by reader Kathy Bohon, call your county Recorder of Deeds and inquire when the property was placed on the tax rolls. The date of construction can be 1-3 years prior or in some cases, much earlier if records are incomplete.
Local town, county, or even state or provincial (in Canada) tax records may indicate the original date of construction of a building
Historical records containing real estate listings include indications of building age
Census records can indicate that a building was present at a particular address at the time the census was taken.
Papers found in the building itself, its archives, will often indicate when the building was present.
Notes and annotations written on the building itself may indicate dates of its age or modification. When we renovated a neo-victorian house in Poughkeepsie, New York we found, on removing aluminum siding, that the siding installers had written their names and the year that the siding was installed (1960).
Historic homes that are in a national, state, or local historic register may include a plaque (photo above left of the Sufflolk Reserves House of 1774) as well as extensive documentation in local historical records. The Suffolik Resolves house (located in Milton, Massachusetts and placed inthe National Register of Historic Places in 1973) whose plaque is shown above documents the Suffolk resolves, a statement of colonial animosity, signed 9 September 1774 and ultimately leading to the United States Declaration of Independence from Great Britian in 1776. Such a home is of course well preserved and documented.
Some examples of conditions that confuse dating the age of a home include
The original home may have been substantially modified, renovated, or a large addition may have been built abutting or even overlaying the original structure.
The home may have been brought to its present site from another location.
The home may have been built on the site of an earlier structure of which no components remain, or sometimes, portions of the foundation of the original structure may be in place but nothing else, for example after a major fire.
Readers are welcome to Contact Us by email to suggest other locations of records that help document the age of a building and the date of its original construction.
Chimneys & Fireplaces as Indicators of Building Age
Here is a photograph of an unlined single wythe brick chimney on an 1856 home in New York State.
The location, size, shape, building materials, and use of chimneys on buildings offer good details aiding in
estimating the age of a building.
These details can also indicate where additional safety inspections
or perhaps repairs or updating are needed for safe use of a chimney, fireplace, building heating
system, or wood stove.
Chimney materials vary among none (a hole in a roof), brick, stone, masonry block,
metal flues, insulated metal chimney flues, and wood-framed metal flues on buildings.
Three different colonial era homes were common in America. Early homes of one room included a chimney at one end. Second were homes that had a chimney at either end, consisting of two rooms with (or without) an entry between them. The third group used a central chimney placed between the two rooms and provided a fireplace in each room. Earliest of these homes were only one-room deep; later they grew to two rooms deep. -- Isham.
Electrical Components as Indicators of Building Age
Here is a photograph of an obsolete 30-Amp electrical meter and fuse panel, ca 1935.
While varying somewhat by area of the country in the U.S., Latin America, Europe, and other areas,
there are recognizable generations of electrical wiring ( knob and tube, greenfield, armored cable or " BX" wiring,
plastic or " NM/NMC" wiring), wiring materials (copper, tinned copper, aluminum, copper-plated aluminum), and
also, easily recognized generations of electrical meters and electrical service panels.
Here we illustrate
various of these materials and products and we provide information about their safety or about the need
to inspect or perhaps replace or upgrade certain problem equipment. See:
Aluminum wiring, although it may have made earlier appearances, was used extensively in new construction in North America from about 1967 to 1975, probably in response to a spike in copper prices, and ending as the fire hazards of aluminum wiring became widely known. Presently solid conductor aluminum wiring is not used in new construction but multi-strand aluminum wiring is still in use for service entry cables and single-appliance high-amperage circuits such as air conditioners and electric ranges. (Overheating and connection failures occur with multi-stranded aluminum wiring too.)
Armored Cable - BX, metallic-sheathed electrical cable was first introduced in 1896 and continues in use in modernized form (with better conductor insulators) today. The earliest armored cable wiring used only paper inside of the insulating steel jacket, a material that failed when the wire was wet or was flexed excessively. Later generations of armored cable used rubber-insulated and fabric covered conductors. We find lots of rubber-insulated armored electrical cables in U.S. homes dating between 1920 and around 1940. Beware of this older armored cable: often the conductor insulation is deteriorated and unsafe, particularly close to electrical lights and other connections where heat may have been present. We've successfully repaired and kept such circuits in use by cutting back the damaged overheated length of wire. Modern BX wiring uses plastic insulated conductors and is available in a variety of wire gauge
s and number of conductors.
Electrical receptacles and device power cord plugs have varied in design and features over the history of electrical wiring;
Un-polarized electrical receptacles: Early electrical receptacles were (and are) usually two-prong, with each receptacle slot of equal size, and with no ground connection for the power cord that is plugged into the receptacle
Polarized electrical receptacles: Electrical receptacles were changed to require proper polarity of electrical connection between the receptacle and the connecting appliance or device cord by making one of the receptacle slots wider and the corresponding power cord plug spade wider than the other. These un-grounded (or unearthed) electrical receptacles (some people call them electrical sockets or wall plugs) are still in use and should still be installed if the electrical circuit to which they are connected does not provide a ground path.
Grounded electrical receptacles: Most modern electrical receptacles (power outlets, wall sockets, wall plugs) provide a combination of polarized connectors (one slot wider than the other) and a ground connection (the rounded opening below the center of the two spade connectors). The most common electrical receptacle used in homes in the Americas, Japan, and some other countries is the 15 Amp (#14 copper wire circuit) receptacle described as NEMA 5-15 15 A/125V electrical outlets. If the receptacle is properly installed with the ground connection "down", the wider slot on the left accepts the neutral connection of the power cord and the more narrow slot accepts the "hot" connection of the power cord.
Beginning with the U.S. 1992 electrical code, special versions of grounded electrical receptacles may shift the pattern of the spade connector slots to provide receptacles that accept both 15A and 20A power cords and others which rotate one of the spade connectors to 90 degrees from the other, to accept only 20A power cords.
European electrical receptacles in modern form (2008) use the CEE 7/16 electrical socket and matching wall plug with openings 19 mm apart and 4 mm in diameter, and that usually does not include a ground connection.That's because european residential electrical circuits are designed for 240-volt circuits (both wires to the receptacle are "hot" and the power cord plug can be inserted in either position. These receptacles are designed for 2.5A/240V circuits with no ground path. A grounded version of this wall receptacle is used in the U.K. (BS 4573) and is called the UK "Shaver" receptacle.
European electrical receptacles of an older design and still found in many buildings in the U.K. and India use a three prong 5-amp 240V BS 546 plug (one is for ground) or a higher capacity BS-546 "M" receptacle rated for 15 amps. The older British 3-pin 13-Amp line cord plug and matching wall receptacle (BS 1363) first saw use after WW II in 1946 and is still found in the UK and some other countries and has two flat 240V pins and a single vertical ground pin connector.
Different electrical receptacles and line cord connectors are used in France (Type E -pin with a female connection to ground (earth) on the line cord plug and a protruding ground pin on the wall receptacle, and in Germany and Russia (Type F two pin with a ground connection provided by a metallic clip below the hot pin connections and at the edge of the line cord plug and electrical receptacle socket. CF: Wikipedia for a nice detailed article describing these connectors.
Electrical Wiring in Old Houses discusses the inspection and repair of old house electrical systems including wiring and other devices
First generation electrical wiring, including from Thomas Edison's D.C. electricity era, used a pair of physically separated copper electrical conductors insulated with cloth and stapled to building framing. Where this wiring was to be exposed to moisture its cloth covering was sealed with tar or similar bituminous compounds and buried in a wooden trough according to a Wikipedia entry. It is unlikely that you'll find this wiring in active use, but if you do, it's dangerous and should be replaced.
Gas piping used to route electrical wires: often in older homes when gas service was discontinued the gas pipes were used to route electrical wires through building walls, particularly when the occupants wanted to install an electric light where a gas light had previously been found. But don't assume all gas piping in an old house has been abandoned - it may still be "live", as we discuss at Gas Lighting Pipes & Fixtures
KNOB & TUBE WIRING details this electrical wiring system, and also see other old house electrical wiring and its history that are provided here. Knob and tube wiring is probably the oldest electrical wiring style that was applied with any standard consistency, and was used from 1880 right up into the 1970's in some jurisdictions, though it fell from widespread use by 1940 when less costly insulated electrical cables increased in popularity.
Rubber-insulated electrical cables were introduced in 1922 and contained two electrical conductors insulated with a rubber coating and wrapped with an asphalt-like impregnated cloth. Some inspectors refer to this as "cloth" or "fabric" wrapped electrical wiring but it's not, it's rubber-insulated.
Wooden floor baseboard trim and other wood molding trims in older homes were often routed on their back side in order to run electrical wires. Be careful in driving nails through wood baseboards before you know if wires are present.
Abbreviated comments on some flooring types are also found just below. In some cases, floor covering such as carpets and tiles have been in use for thousands of years. If we comment on these materials it is to identify certain modern variations such as ceramic bath or wall tiles that are purchased pre-glued to a mesh backer to speed tile placement. But in general we focus on flooring materials that have special properties, ability to date the era of their use, or environmental concerns.
Various types of flooring and the inspection, diagnosis, and repair of flooring defects are discussed at FLOORING TYPES & DEFECTS. Types of building flooring that contain asbestos, a health and environmental concern, are discussed in detail at Floor Tiles Containing Asbestos.
List & History Resilient Floor Coverings Used in Buildings
Resilient floor coverings include organic flooring materials such as asphalt tile, cork tile, linoleum, rubber flooring, vinyl tile, vinyl sheet flooring.
Asphalt Tile Flooring as an Indicator of Building Age - 1920 - 1960 (est)
In 1920 asphalt roofing manufacturers, who had been using asphalt and fiber binders to make asphalt roofing shingles for some time, tried to develop a rigid product that could be a substitute for (more costly) slate roofing.
The material did not perform acceptably as a roof covering, but it led to the development of asphalt floor tiles.
Asphalt floor tiles are 9" square (or other sized) tiles which used asphalt as the main binding material. the original asphalt tiles were produced only in dark colors because asphalt was a main ingredient.
Rosato indicates that the first publicized asphalt tile installation was in 1920 in New York City's Western Union office.
The product was very successful and by 1936 over four million square yards of asphalt floor tiles were being sold annually. By 1940, 5% of floor coverings sold in the U.S. were asphalt tile. -- Rosato
If you encounter black or very dark asphalt floor tiles they are probably very high in asbestos fibers. We discuss floor tiles as an asbestos fiber source in buildings in more detail at Floor Tiles Containing Asbestos.
Cork Flooring Tiles as an Indicator of Building Age -
Cork floor tiles were considered a warm, quiet, but less durable resilient floor covering than some of its competitors. It was sold often for use in residential dens, family rooms, or other warm, low-traffic areas, and it may have been popular (research needed) for use in areas where workers had to spend long periods standing - where it would have competed with rubber floor coverings. In 1952 cork flooring sales made up 2% of total floor tile sales. -- Rosato p88.
Vinyl Asbestos Floor Tiles as an Indicator of Building Age - 1930 - 1976 (est)
Vinyl floor tiles, including vinyl-asbestos floor tiles and homogenous vinyl floor tiles (non-asbestos product) are almost as old as asphalt floor tiles. By the early 1950's in the U.S. vinyl tile floor products were more popular than asphalt-based flooring. The reason is pretty obvious.
Asphalt-based flooring as it was originally produced used heavy asphalt products which meant that the floor tiles could be made in dark colors only.
Soon after asphalt-asbestos floor tiles were marketed manufacturers heard from their buyers that consumers wanted lighter floor tiles and tiles of varying color and pattern.
Organic resin vinyl increased in popularity for this reason, but slowly. By 1952, the production of vinyl plastic floor tile sales in the U.S. was about half the volume of asphalt floor tiles, selling 35 million square yards.
Sheet Flooring Materials That Indicate Age of a Building
Here is a photograph of an early (pre-vinyl) continuous floor covering, ca 1900, in an 1840 historic Vermont house.
Note the fabric backing of the flooring material.
Here we discuss various common flooring materials (rough wood, finished wood, parquet, carpeting,
linocrusta, sheet vinyl, and other items as they assist in determining The age of a building or other building.
Linoleum Sheet Flooring As an Indicator of Building Age - 1890 - 1960 (est)
According to Rosato, "The original resilient floor coverings were developed during the latter part of the Nineteenth Century by Frederick Walton. The original covering was linoleum for use as a floor decking on British naval ships." The composition of the original products included asphaltic binders to which an asbestos filler was added by mixing on a rubber mill.
List of Non-Resilient Floor Coverings Used in Buildings
Non-resilient floor coverings used in buildings that can assist in determining the age of a structure include bamboo, brick, concrete, stone, and a wide variety of wood products.
Determining the Age of Buildings Using Laminate Flooring Products
Contemporary snap-together flooring products that resemble wood or other surfaces, but are made of plastic, and other pre-finished and ready-to-assemble wood flooring products are a much more modern product.
Sadly the laminate floor shown at left was ruined by a building flood.
Pergo™ laminate flooring, for example, was developed by Pergo AB, a Swedish company founded around 1890 as a vinegar manufacturer. Product development for Pergo laminate flooring began in 1977 and was first brought to the market in 1984. Pergo laminate flooring was first sold in the U.S. in 1994.
Foundation Materials as Indicators of Building Age
Foundation materials commonly used for buildings include:
Wood, beams set on grade or on flat stone set on or close to ground level
Stone, natural found on site or brought to the building site
Brick, less commonly used below grade, more often used from grade-level up, set on stone below grade.
"Cinder blocks" or concrete blocks
Poured concrete
Pre-fabricated concrete foundation sections assembled onsite (photo at left)
Wood, treated lumber, treated plywood on treated wood or on concrete studs
Photograph of a buckling, damaged stone foundation on an 1864 structure in Rhinebeck, NY.
In evaluating the probable age of a home when inspecting its foundation, we consider the foundation
materials and style of workmanship.
A building's foundation materials and style of construction, stone, wood, brick, masonry block (at least
two different generations), and poured concrete (various generations and methods including hand-built
and by machine and pumper truck) can give considerable information about the foundation age.
On occasion
we'll find a very old structure which has been moved and re-set on a new concrete or concrete block foundation,
adding more historical information to the home.
All of the common building foundation materials, how they fail, how they are inspected, are discussed at The Foundation Crack Bible.
Logs, various sizes, chopped, dried, assembled at the building site
Hand hewn beams, chopped and then sized with an adze and axe. Adze cuts and axe cuts are normally visible in the rough surface of hand hewn wood structural beams.
Full-sized 2"x4" (or larger 2 x n") wood framing materials
Modern wood framing wall studs 2x4's (3.5" x 1/5") and larger members (x" deep by 1.5" thick)
Glulam beams; large timbers are built-up of laminated wood strips
Tongue and groove wood subflooring, wall sheathing, roof sheathing
Plywood subfloors, wall sheathing, roof sheathing
Oriented-strand board subflooring, wall sheathing, roof sheathing - see OSB
Here is a photograph of post and beam framing with joint number markings.
The observation of
framing materials, framing markings, and framing styles provides considerable information about the
probable age of a house.
We discuss framing materials and styles here as an aid to house age determination.
Below we provide abbreviated discussion taken from the full-text articles listed above.
Arkansas framing system: 2x6 wall studs are spaced 24' on center, a spacing that permitted installation of more wall insulation volume than provide by conventional 2x4 wall studs.
The Arkansas building framing method became popular in North America following the 1970's arab oil embargo and addressed concern for high energy costs.
Tall wall studs run from the sill plate atop the foundation wall to the top plate below the building rafters. Wall studs and first floor joists rest on the building sill plates (flat wood members set atop the building foundation). The wall studs extend from the first floor sill to a height sufficient to frame both the first and second floor walls.
First floor joists and second floor joists are framed by nailing to these tall wall studs at the appropriate heights. Rafters attach to the top plate of the building walls. Ceiling joists for the top floor are nailed to the sides of the balloon-framed wall studs just as the floor joists were nailed below.
(1640 - est U.S.): solid logs usually felled and prepared at or close to the building site, set on ground level, on flat stones on ground, or on a stone foundation, corners joined using various notch and overlap methods. See Log Home Guide.
Modular construction (1910 - present) was first provided on a large scale with Sears Kit homes that were distributed from about 1910 to 194o0 - see How to Identify Sears Kit Houses.
Some modern modular homes built in the U.S. during the 1950's post war building boom originally enjoyed a less than stellar reputation several decades ago, having the reputation of flimsy construction.
That is no longer the case. Since at least the 1980's a modular home is constructed in a factory of one or more sections which are carried to the building site on a trailer (photo above left) and lifted by a crane to be set upon a foundation which has been prepared ahead of time.
Modular homes can be quite large, involving four or quite a few more individual sections which are lifted and "set" into place at the site (photo at left)
Some manufacturers provide custom architectural services and can deliver unique, but factory-built homes in sections. Contemporary modular construction of homes have these attributes:
OSB - Oriented Strand Board Used in Building Construction, History, Description, Identification
Panelized construction: floor and wall panels constructed in a factory are delivered to and assembled at the building site. Panels may be conventionally-framed stud walls in modular sections or structural panels may be constructed of a sandwich of OSB (oriented strand board), plywood, or wafer board on either side of solid foam board insulation.
Panelized construction makes use of wall, floor, ceiling or roof "panels" which have been framed off-site and brought to the site by truck. Panels are lifted into place by crane and fastened together on a foundation, and possibly a framed-in floor which have been prepared before the panels arrive.
Some framing panels make use of special materials, such as plywood and foam roof panels for insulated cathedral ceilings.
(In process, contributions invited).
Plank House or Box Construction Method Defined & Described
1880 - 1920 estimated, with some plank house construction continuing up to possibly 1950. Plank houses were constructed entirely of sawn planks and without the use of larger dimensioned 2x lumber. Some of the plank houses we've inspected were made from scraps or salvaged lumber such as a home in Dutchess County New York that was constructed from packing crate wood. Larger collections of plank houses were built as company housing in the mining or railroad industries.
(In process, contributions invited).
Platform Framing Construction Method Defined & Described
The platform frame construction method, also called western construction is the most-common residential wood structure framing method in North America. A floor is constructed atop of the building foundation, forming the first "platform", using the platform as a working surface.
Plywood Used in Building Construction, History, Description, Identification
Plywood (1905 - present as a construction material in North America) is sheet material made of thin veneers of wood that are laid with wood grains in alternating direction, glued, heated, and pressed together. Interior plywood is generally glued with urea formaldehyde based glues; exterior plywood and marine plywood use phenolic formaldehyde glues and are water resistant.
The cross-grain construction combined with glue produces a strong, uniform material that is used for both enclosure and for structural stiffness in frame construction of building walls and roofs. The properties of plywood, including its tolerance to weather exposure (marine plywood) depend on the glues and finishes used. Both softwood and hardwoods are used in plywoods, and fine wood veneer finishes are also available (for furniture use).
Also see Oriented-strand board subflooring, wall sheathing, roof sheathing - at OSB
Post & Beam Construction Method Defined & Described
Post and beam construction (1700 - est. in North America): (timber framing) uses horizontal and vertical timbers that are connected (joined) using mortise and tenon joints pinned with wood pegs (treenails).
Timber frame construction initially used hand hewn beams, later manually or mechanically sawn beams cut by a pit saw.; Later timber frame beams were sawn in mills using circular saws.
Timber framing using post and beam construction with mortise and tenon joint connections was used in Europe for at least 500 years before it was first employed in North America.
By 1650 a typical timber frame building used multiple bents and girt beams, may have been more than one story tall, and included an exterior made of horsehair-reinforced cement stuccoed over hand-split lath. Our photo (above) shows an 18th century Norwegian timber frame building using brick infill and stucco to complete the wall enclosure.
Welded Wire Sandwich Framing Panelized Construction
Welded-wire sandwich framing panels: polystyrene or polyurethane foam core insulation is surrounded by a welded-wire space frame.\
non-standard wood framing spacings, typically in post and beam or hewn beam frame construction
14" spaced wooden stud framing - early balloon framing
24" spaced wood stud and wood rafter framing, based on a 24" module - all framing, wall studs, floor joists, roof rafters are spaced 24 inches on center. See Arkansas framing above.
16" spaced wooden wall stud and wooden roof rafter or wood roof joist framing
Gas-fired furnaces, boilers, steam boilers - see AGE of HEATERS, BOILERS, FURNACES - AGE of heating equipment, boilers, furnaces by decoding data tags
Electric furnaces and heating boilers
Geothermal hot water heating systems (Iceland)
Heat pumps - see AGE of HEAT PUMPS - how to read data tags to decode the age
Above we show a photograph of an "octopus heating furnace", originally coal fired,
usually by now (if still in use) converted to natural gas fuel.
These octopus furnaces, also called "gravity heating systems" provided heat by natural convection,
hot air rising into the building from the top of the furnace where it was delivered
to the building first floor through a wood or iron grate, or perhaps delivered
through metal ducts.
The original installation usually supplied heat to a home through a
central grate in the first floor of the building from where warm air might rise
to upper floors. Later versions or modified original systems
added ducts to individual rooms, sometimes still only on the first floor of the building.
These furnaces are the ancestor of modern forced hot air heating systems.
Here we discuss types of heating systems ( octopus furnaces, forced air heating systems, steam boilers, forced hot water boilers, high efficiency systems) and fuel types
(coal, oil, gas) as an aid in determining the age of a home or other building. Where
there are special safety or maintenance concerns for certain systems we cite those as well.
Insulation Materials as Indicators of Building Age
Insulation materials used in buildings includes:
Nothing - no insulation - solid log walls, solid stone walls, providing thermal mass. Chinking or other methods used to reduce air leakage were the principal energy savings or comfort detail applied; adobe and concrete construction.
Air - open cavities in wood framed walls; a small 1" air gap is also found in older structural brick walls; the air gap in brick walls was intended to avoid transmission of moisture from outside the building to its interior.
Silage or corncobs used as wall insulation
Paper, newspaper, rags used as wall insulation
Brick, masonry, as wall cavity fillers to block air leaks and provide thermal mass - see brick-lined walls as building insulation
Cotton building insulation batts - see cotton building insulation
Perlite building insulation - see perlite building insulation
Asbestos used as insulation in buildings, generally on heating pipes (corrugated asbestos paper lengths wrapped around pipes, asbestos paste at elbows and on boiler exteriors, asbestos paper on heating duct exteriors); asbestos was not normally used as a fill material for the insulation of building cavities though we have encountered it in rare cases. See asbestos insulation.
Rock wool or mineral wool used as building wall or ceiling insulation - see rock wool insulation
Paper or foil air and heat reflective barriers used as ceiling or wall insulation in buildings
Chopped, fire-retardant cellulose (newsprint) building insulation - see cellulose building insulation
Chopped fiberglass building insulation
UFFI urea formaldehyde foam insulation used as building insulation - see foam spray building insulation
Foam board building insulation products: styrofoam board insulation, other foam insulating board products, paper faced and foil faced insulating boards - see foam board building insulation
Insulated building panels, a wood "sandwich" of solid foam board and plywood, used primarily on building roofs
Icynene® foam building insulation
Latex foam building insulation and other foam insulation products
At Insulation Material Identification Guide we discuss various types of insulation materials (none, air gaps, brick and brick-lined walls, cellulose, cotton, corn or corn husks, hay bales (including hay bale or straw construction),
straw, newspaper, rock wool insulation or mineral wool, fiberglass insulation of various colors (brands), types (batts,chopped, etc), perlite building insulation, asbestos insulation and fire barriers, UFFI and other more modern foam board and foam spray insulation materials,
and the use of radiant barriers) and their common eras of usage
as an aid to determining the age and history of a building.
Our photo at left shows a pre-1900 brick wall lining used as insulation and as a wind or draft block.
Brick nogging can determine the probable age for the home.
Houses built between 1810 and 1900, or perhaps earlier may have brick-lined walls.
I have found brick nogging in the walls of a 1790 Poughkeepsie NY home.
Bricks lining the walls of a home is an indicator of when it was built.
See Brick Lined Walls for a detailed, illustrated article about the use, detection, and inspection of
brick lined walls in older homes were we describe and explain the reasons
for and concerns with brick wall lining or "insulation" sometimes called nogging.
Guide to Nails and Hardware as Indicators of Building Age
A close observation of the type of fasteners used in a building is one of the most popular means
of estimating its age. Hand wrought nails, machine cut nails, modern round "wire" nails and other
details offer considerable information about the time of original construction of a building
as well as of the time of modifications to the structure.
Tremont Nail Company continues to manufacture reproduction nails which in appearance are quite like
those made by hand more than 100 years ago.
Tremont supplies restoration contractors and others working
on historic buildings and for historians, Tremont offers a reference set of old fasteners. (See Tremont
at "More Reading" below.)
Shown is Tremont's standard Clout Nail:
Similar in design to Shingle Nails, but made from lighter gauge steel.
this nail was (and is) used for the application of thin siding and paneling.
It was and is also used for furniture repair, cabinet work, batten doors and counter tops.
(Photo courtesy Tremont Nail Company).
Window Latches, Fasteners, Tracks, Window Weights, and Window Components as Indicators of Building Age
The window latch shown in our photo (left) dates from the 1840 Justin Morrill Smith Historic house in Vermont.
(Photos of various window hardware components wanted. Contact Us)
Guide to Plaster & Drywall & Other Interior Wall Coverings as Indicators of Building Age
Please see Plaster & Beaverboard & Drywall we describe and discuss the identification and history of older interior building surface materials such plaster and lath, Beaverboard, and Drywall - materials that were used to form the (ususally) non-structural surface of building interior ceilings and walls.
Readers should see Sheathing Homasote & Other Board for a discussion of exterior wall sheathing fiberboard products such as Homasote® and Celotex® insulating roof, wall, and foundation board products.
A quick review and description of these materials is provided just below.
History of Plaster, Plasterboard, Drywall, Wood Lath, Metal Lath
Photograph of hand-split wood lath and plaster wall, from the wall-cavity side. Ca 1800.
There are several generations of plaster and lath, plaster board, and drywall which have been used
in buildings.
We name and illustrate these and discuss their periods of use below as an
aid in finding out how old a building is and tracing its history. Examples:
Mud used as a plaster over split wood lath or woven wood lath
Horsehair mixed with plaster or cement for building exterior wall covering
History of Beaver Board & Upson Board Wall Coverings in North America
Details about Beaver-board and Upson Board, a wood fiber product used as an inexpensive interior wall covering and draft blocker from about 1903 are provided at Plaster & Beaverboard & Drywall.
Our photographs (below) show this product from it's back or wall cavity side. On the exposed side this wood fiberboard product was usually painted and its joints covered with wood lath or other trim. In some applications it was covered with wallpaper. In some homes it was later covered with drywall to provide a more fire-resistant surface.
Beaverboard takes its name from the Beaver N.Y. and the Beaver Board Companies that produced this product until that firm was purchased by Certain Teed Prod cuts in 1928. Beaver Board and Upson Board were produced by the Beaver Wood Fibre Company Limited, in Thorold, Ontario.
Beaver board's competition was from Upson Processed board (John Upson, Upson Company, Lockport, NY) which was produced beginning in 1910. As late as the 1950's Upson Board was used in prefabricated houses and exterior building sheathing and in recreational vehicles. Upson purchased the Beaver Board plant from CertainTeed in 1955. Upson began its decline in the 1970's and closed in 1984, opening later that year as Niagara Fiberboard.
Photograph of an active gaslight found in a 1900 home in New York.
Often old gas lines have been disconnected entirely and sometimes they have been re-used to route electrical wiring to
new light fixtures or to gaslight fixtures which have been converted to electric.
Don't assume
that an old gas fixture or valve on a wall or found in a fireplace are inactive.
We turned-on and lit this fixture which gave a bright surprise to everyone.
Chart of Dates When Different Types of Plumbing Were Used in Homes
Plumbing fixtures and piping materials offer considerable age in dating a building, including easy
clues such as the presence of a date of manufacture stamped into many toilet tanks to the periods
of use of types of water supply piping (lead, galvanized steel, black iron pipe, copper, plastic piping)
and building drain piping (lead, cast iron, copper, plastic, clay).
Often on older buildings multiple
types of piping will be present as repairs and changes have been made in the building plumbing system.
Chart of plumbing types and years of use courtesy of Carson Dunlop
Wood shingle roofing has been in use for hundreds of years in the U.S. and Europe.
But an inspection of
interior and exterior roofing details can indicate the probable age of a wood roof (which can last up to
40 years) as well as the roofing history of the building, the number and types of roofing layers, and related
house-age-determination details.
The wood shingle roof shown in the photo below is on a building in Key West, Florida,
adjacent to the Hemingway house, viewed from the Key West tower. Notice the absence of lichens on the
wood shingles in the roof area below the metal-flashed rooftop tower?
We discuss here various roofing materials (Wood, slate, asphalt shingles (in several generations),
clay tile, metal roofing (several styles and generations), and how they assist in finding The age of a building below.
History and Dates of Use of Various Roofing Materials
(in process)
Here we discuss the eras of use of different types of roofing materials as an aid to understanding the history and age of buildings. If you are trying to determine the age and condition of a particular roof covering, please see Roofing.
Saw Cuts, Tool Marks as Indicators of Building Age
The saw cuts visible by flashlight on this sawn beam form an irregular "vee" shape, a
clear indicator that this beam was cut by hand using a two-person pit-saw.
This beam was
cut before mechanical saws were available, but after hand-hewn beams or raw logs were in common use. This places the age of
this structure perhaps in the mid 1700's.
We can contrast
these saw marks with the mechanical pit saw which followed, then with circular saw marks,
and later with planed dimensioned modern lumber of two generations. We include illustrations
of these markings and surfaces below.
Adze marks on hand-hewn beams, generations of types of saws used in cutting beams, and similar
details are readily available on many buildings and offer both clues to building age and
wonderful aesthetic detail.
An understanding of how hand-hewn beams were cut, for example, can
permit the careful observer to not only recognize the type and age of building framing, but even
to understand just where the worker was standing when a blow from a tool was delivered to a
building framing member.
This detail offers a very personal connection to the age of a building
and to its past construction.
A photograph of stencil numbers on wood framing shown here confirms that this building was a Sears Kit House whose
model and probable age we can determine.
Other kit homes were sold by Montgomery Ward and by a few other manufacturers
including copies of some of the popular Sears and Roebuck houses that continued to be sold after Sears had
discontinued their production.
Here we discuss types of kit homes including kit houses and log home kits which, in the latter instance
continue to be improved and sold.
Asphalt siding such as that shown in the photo of an extension on the rear of the Coolidge Hotel in
White River Junction, Vermont, was the "aluminum siding" of the 1930's and 1940's in the United States.
That is, it was a popular "no maintenance" siding material sold often as a cover-up product for
older siding in poor condition. (Aluminum siding and then vinyl siding were sold both for that purpose and
also as exterior wall cladding for new construction as well).
Asphalt siding material was made in two common versions, one much like asphalt roof shingles and the other (as
in this photo) was comprised of an asphalt coating laminated to hardboard siding material.
Commonly made to
look like brick, it also appears in faux-stone versions (not to be mistaken for "perma stone" which has been
sold since the 1960's as an exterior wall covering. It would be rare
to find asphalt-based exterior siding material as original wall cladding on a building; usually it was applied over wood clapboards which in turn
were badly in need of paint or repair.
History and Dates of Use of Various Building Exterior Siding Materials
Details of how this material deteriorates and examples of its variations are discussed
below along with other exterior siding materials and their common dates of use.
Windows & Doors & Interior Hardware as Indicators of Building Age
Here is a photograph of an 1840 window latch on a historic landmark property, the Justin Smith Morrill Homestead in Strafford, Vermont.
Here we discuss windows and doors as clues to building age, including window style, size, placement, construction,
and hardware, as well as door style and hardware.
Square D Circuit Breaker Recalls, announced by the US CPSC, recalls include a Square D GFCI circuit breaker distributed by Square D, and a Counterfeit Square-D circuit breaker sold through Scott Electric
Flooring Materials: history of types and age of different flooring materials: Asphalt or vinyl-asbestos floor tiles, sheet flooring, linoleum, ceramic tile, carpeting, wood floor types and materials
Foundation Crack Bible, in-depth diagnosis, and evaluation of all types of structural and non-structural cracks in residential foundations [Brick, Concrete, Masonry Block, Stone]
More Information on Building Diagnostic Inspections and Repairs
...
InspectAPedia® Home & Site Map - Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice: In-depth research & advice on diagnosing, testing, correcting, & preventing building defects & indoor environmental hazards. Unbiased information, no conflicts of interest.
The Mold Information Center: What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems
Environmental Inspection, Testing, & Diagnosis On-Site IAQ, Gas, Air Testing, Mold Investigation, Sick Building Diagnosis, Lab Services, & Remediation Plan Preparation - indoor air quality testing, problem source determination, supporting lab work, written remediation plan addressing removal of environmental and other hazards and prevention of their recurrence.
InspectAPedia ® Home & Site Map 
Window Latches, Fasteners, Tracks, Window Weights, and Window Components as Indicators of Building Age
InspectAPedia® Home & Site Map - Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice: In-depth research & advice on diagnosing, testing, correcting, & preventing building defects & indoor environmental hazards. Unbiased information, no conflicts of interest. 
A photograph of stencil numbers on wood framing shown here confirms that this building was a Sears Kit House whose
model and probable age we can determine. 
