Old log cabin © Daniel Friedman at Building Framing & Sheathing Materials

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How to determine the age of building framing or sheathing materials:

A Photo Guide to Types & Age of Framing Beams, Rafters, Studs, Lumber & Sheathing.

This article provides a photo guide to determining building age by examining its structure. We describe building framing materials used in different epochs of residential construction. Knowing when certain materials were first or last in common use can help determine the age of a building.

We list various kinds of building materials and give the history and dates of their first (and in some cases last) use in residential and light commercial construction.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Framing & Construction Materials as Indicators of Building Age

Modern post and beam construction © Daniel Friedman at

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. Our page top photo shows modern floor framing details for a modular-constructed house.

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.

Antique and modern trusses are distinguished and modern laminated beams and I-truss beams and wood joists are discussed.

Article contents

At above left our photo illustrates a modern (21st century) post-and-beam construction using milled timbers but traditional mortise and tenon and treenail connectors.

Post and beam modern construction (C) Daniel Friedman at

Cement Board & Fiber Cement Building Products

Asbestos-Cement Board & Fiberboard Products

Exterior Siding & Roofing Using Asbestos Cement included asbestos cement shingles, asbestos cement siding, corrugated asbestos-cement roofing.


Other fiber cement materials used in construction included


Modern Cement Board & Fiber Cement Products

Cement board is a non-structural building sheathing material which in its contemporary form is made from Portland cement covered with a reinforced fiberglass mesh fabric. Cement board is used as a tile backer or a backer board for stucco applications on buildings. Current producers include Custom Building Products (WonderBoard™) and US Gypsum (Durock™).

Panels made of a mixture of cement and wood fibers are produced for building siding by James Hardi (Hardi-panel and Cemplank™), and CertainTeed (Weatherboard™).

(History & dates in process, contributions invited - CONTACT us)

History of Dimensional Lumber Used in Building Framing

Platform framing © Daniel Friedman at

Dimensional lumber that initially actually measured as equal to its nominal size (a 2x4 was actually 2" x 4") was produced beginning in 1833 in the U.S. (Augustine Taylor, building St. Mary's church in Chicago in that year) and was the dominant framing material in the U.S. by 1900.

Our photo (left) shows the interior of a modern platform-framed structure going up in Minneapolis, MN in 2008.

The appeal of dimensional lumber was the reduced time and effort to construct a wood frame building compared with hewn timber frame beams that had to be cut and shaped, air dried for two years, and joined with mortise and tenon joints that required more highly skilled carpenters.

Initially church members were concerned that their building was being built of flimsy too-small sticks and scaffolding materials.

But 2x4 and other dimensional lumber did not remain exactly the same physical size as its nominal size, and by 1940 or earlier the finished size of most framing lumber products was notably less than the nominal size. A modern 2x4 is approximately 1 1/2" x 3 1/2" in cross section.

What Lumber Species Were Most Common in Older North American Wood-Framed Structures?

The table given below is of general interest in understanding the most-widely-used framing lumber species in North America up to about 1985. However it is likely that especially in buildings constructed before 1900, lumber came from local mills and was milled from local tree species - a fact that will change the probable species of woods used in antique structures.

Most-Common Framing Lumber Wood Species in North America 1

Framing Lumber Wood Species To Early 1900's Framing Lumber Wood Species To Late 1900's Comments
Red Cypress*#
Douglas Fir-coastal#
Douglas Fir – inland*#
Pacific Coast Hemlock#
Western Larch*#
Eastern Hemlock*#
Eastern Spruce*#
California White Pine#
White Pine (Northern, Idaho, and sugar)#
Norway Pine#
Port Orford Cedar#
White Fir*#
Long leaf Southern Pine#
Short Leaf Southern Pine#
North Carolina Pine#
Arkansas Soft Pine#
Southern Yellow Pine#

Douglas Fir

Hem-Fir - Hemlock / Fir

Southern Yellow Pine - also referred to as


Spruce-Pine-Fir - also referred to as SPF

Southern Pine

Audel’s mentions White Pine as the most common framing lumber on the East Coast in the early 1900s,

which is also confirmed by similar references in the Sears catalogues.

* Species reported as being appropriate for studs (No. 1 or No. 2 grade recommended)

# Species reported as being appropriate for joists and girders (No. 1 grade recommended)

Notes to the table above

For help with visual identification of wood species I particularly like

Is Modern 2x Pine Lumber as Strong as Antique 2x Pine Lumber?

Broken rafter © Daniel Friedman at

Our opinion is that modern dimensional lumber is not the same product as it was in 1833 or even 1940. Modern 2x lumber is produced from trees that have been developed to grow rapidly to a size at which they can be harvested.

Rapid tree growth means wide-spaced growth rings which may mean softer, weaker wood than dense-grained first-cut timbers or lumber.

That combined with the increasing number of knots (as 2x's are cut from ever smaller trees) means that the building frame must rely on additional materials (such as plywood or OSB sheathing) for a critical part of its strength.

Details about the evolution of lumber standards are at FRAMING AGE, SIZE, SPACING, TYPES.


Where lumber strength vs. size, weight, or bending resistance is a particular design concern, architects and engineers may specify an engineered wood product such as a laminate-beam or wooden I-trusses or trusses where that strength is needed.

Other framing material & hardware details can assist in determining building age. An examination of nails and fasteners and other building hardware is a complimentary effort useful in determining the age of a building and its components. (NAILS & HARDWARE, AGE).

as well as SAW & AXE CUTS, TOOL MARKS, AGE for additional building age clues likely to be available when examining building framing materials.

Engineered Wood Product Building Construction Materials History & Dates

Laminated beams © Daniel Friedman at I_Joist floor support © Daniel Friedman at

Our photo (above left) shows a modern laminated wood structural beam in both side and end view. (Make sure that your builder uses proper connectors and supporting posts, not the goofy structural setup in our photo). Our photo of I-joists (above right) shows this engineered floor support system in use in a Minneapolis home under construction in 2008.

Fiberboard Building Sheathing: Black board, grayboard, buffaloboard exterior sheathing

Fiberboard sheathing © Daniel Friedman at

In addition to plywood, OSB, and gypsum board, impregnated fiberboard has been used as exterior building insulating sheathing in North America since at least 1909.

Fiberboard wall sheathing, when intended for use on a building exterior is installed by nailing directly to the wall studs, most often with let-in diagonal bracing or plywood panel bracing at the building corners to assure building rigidity.

There both non-structural and structural fiberboard panels that did not require this additional bracing have been produced.

Some fiberboard sheathing products can claim adequate structural shear strength, particularly if the proper nails and nail pattern are used.

Other contemporary producers of fiberboard building sheathing include International Bildrite (Bildrite structural), Georgia Pacific (Stedi-R & Stedi-R-structural), Knight Celotex (Celotex premium insulating), and Temple Inland (Temple fiber brace).

Fiberboard sheathing, also called black board, gray board, or buffalo board sheathing in some areas, is a fibrous material impregnated with a stabilizer and water repellant - asphalt on early versions of this material that we have found.

While it's not easy to find and identify this material on a building wall unless indoor or outdoor demolition is being performed, you can spot the product in building attics on the gable-end walls.

The R-value of fiberboard sheathing is higher than plywood, gypsum board, etc, and is rated at about R 2.4 per inch (or about R 1.2 in more typical half-inch thickness with which it is applied. The board also reduces sound transmission into buildings.

Details about fiberboard sheathing products including Celotex & Homasote & Masonite are found

at FIBERBOARD SHEATHING (separate article) and Masonite™ (in this article).

Gypsum board building exterior wall sheathing

Gypsum board wall sheathing © Daniel Friedman at

[Click to enlarge any image]

Gypsum board has been used for non-structural wall sheathing and even roof sheathing on buildings for more than 50 years in North America alone.

Above is a row of 1940's buildings constructed at Stewart Air Force Base in Newburgh, New York, apparently as military housing. Some of these structures are still in use while others (foreground) are being demolished.

Originally a brick veneer covered the structure, behind which was this black paper-covered gypsum board sheathing.

An ongoing demolition project ca 2012-2014 has removed the brick veneer from several of these buildings, leaving the gypsum-board sheathing exposed to the weather.

Details about moisture-resistant gypsum panels or gyproc are at SHEATHING, GYPSUM BOARD

Hewn Beams & Pit-Sawn Planks as Construction Materials - Help in Determining Building Age

Hand hewn beam © Daniel Friedman at

Above: hand hewn beams, chopped and then sized with an adze and axe were used in North America from the 1600's into the late 1800's.

Timber frame construction initially used hand hewn beams, cut roughly rectangular by an adze and axe.

Details about chopped or hewn timbers and beams are at AXE ADZ HEWN BEAMS & PLANKS

Roof framing 1790 © Daniel Friedman at

Our photo at above left shows typical roof framing on a Poughkeepsie home built ca 1790.

See SCRIBE & SQUARE RULE MARKS on TIMBERS for details abou thow these marks were used.

Pit saw kerf marks indicate age of a framing timber © Daniel Friedman at

Our photo-left, shows a hand-sawn pit-saw cut beam or plank.

For details about post and beam construction methods see our full text article at Post & Beam Construction.

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. Timber framing in North America continued until about 1920. (CF Reference due: Age of Barns, op. cit.)

Reader comment: first timbers cut with broadaxe

2016/07/28 Anonymous said:
The first timber introduced was done with a common axe, probably a double bit. It was not done with an adze

This comment appeared originally at SAW & AXE CUTS, TOOL MARKS, AGE


Thanks for your comment, Anonymous;

I agree that intial cutting timbers was done with an axe and sometimes rough-hewn timbers may have been prepared with an axe but more commonly those first hewn timbers were used as round logs, sometimes with bark-on.

Lehman (2015) agrees that the broadaxe was used for hewing timbers (cutting down trees), a broad hatchet was used for hewing smaller timbers, and "The Carpenter's Adze-used to finish levelling the surfaces of sleepers and other floor pieces."

It's possible to somewhat flatten one or more sides of a round log using an axe, or double-bit axe.

Some timbers were hewn flat on just two sides, such as in the Missouri-French houses.

Most four-sided squared timbers we'll see in older buildings in Europe, the U.K., Russia, and in North America in standing buildings were flattened using an adze or a combination of adze and axe in which the axe made straight-on cuts into the log and the adz chopped out those chips and further flattened the surface.

Interestingly the adze is not a modern tool; it dates from pre-historic times when people made an adze out of chert or other stone.

Do you agree?

Research citations on hewing timbers and on early use of the adz or adze:

Identifying Photographs of Homasote®, Celotex®, & Similar Fiberboard & Insulating Sheathing Board Products

Fiberboard sheathing like Homasote © Daniel Friedman at

Insulating building sheathing made by Homasote® is produced by the Homasote Company, a manufacturer in the U.S. in New Jersey, and similar fiber sheathing products have been used both as a sound barrier and for exterior sheathing on buildings. Insulating board sheathing has been widely used on building exterior walls, under roofs, and against masonry foundations in finished basements.

Originally, Homasote produced sanded "agasote" sheets used in the roofs of passenger railroad cars, moving, in 1915, to automobile roofs, and in 1916 to construction products. Homasote was widely used for military barracks in both WWI and WWII and is still promoted for sound resistant sheathing and other applications.

Homasote and similar insulating building sheathing board products are still sold as a lower cost alternative to plywood or OSB for building sheathing. The product is used as structural paneling, insulation, concrete pouring forms, and expansion joints.

Homasote type insulating sheathing board © Daniel Friedman at Homasote type insulating sheathing board © Daniel Friedman at

Our photos (above left and right) show close ups of Homasote-type insulating building sheathing board products, including a torn cross section showing the layered fibrous character of this material. Where structural shear strength is needed by using the company's recommended ring-shanked nails in a specified nailing pattern.

Homasote Co., the oldest manufacturer of building products from recycled materials in the United States, was founded by Eugenius Harvey Outerbridge as Agasote Millboard Company, and has been producing this material since 1909. In 1936 the company changed its name to its best known product, Homasote.

Our photographs below show Celotex® insulating board with an older Celotex fiberboard building sheathing board at left and a more recent Celotex insulating board product shown at below-right.

Also see this close up of an older Celotex insulating sheathing board product.

Celotex old insulating board © Daniel Friedman at Celotex tuff-R insulating board © Daniel Friedman at

Details about fiberboard sheathing products are
at FIBERBOARD SHEATHING (separate article)

Also see Fiberboard insulating sheathing or board sheathing products discussed in this article (above) and see Masonite® hardboard siding products also discussed in this article.

Log Home Construction Materials

Elk Lake Michigan Log Cabin © Daniel Friedman at

Our photo above shows traditional hand hewn logs and a log joint on a Norwegian cabin outside of Oslo. [Click to enlarge any image]

Antique Log Home Construction

(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.

Below: logs used as widely-spaced rafters in a home built in 1865 and photographed by Rockland County NY home inspector Dobver Kahn.

Log rafters in an 1865 ranch inspected by home inspector Dobver Kahn (C) 2018

In our OPINION these log rafters do not provide framing to modern structural standards. Their actual structural evaluation, even by a licensed professional, is difficult as the logs are not a standard building material in dimension nor in consistency.

Log rafters in an 1865 ranch inspected by home inspector Dobver Kahn (C) 2018

An experienced inspector observing log roof support framing like this will report evidence of insect damage, rot, sagging, separation of structural connections, and even where these are not observed he or she will cite non-standard framing that might need additional investigation or support.

Details about log home construction for antique, historic, old or traditional log cabins are discussed in these articles:

Modern Pre-Cut Log Home Construction

Modern log construction © Daniel Friedman at

Typical modern log homes use 6" or larger diameter factory milled logs that are cut to precise dimensions and whose design includes interlocking splines and gaskets to protect against leakage. In our photo (left) you can see the notches on the log bottoms and the log-end profile shows the raised splines on the top of each log.

See HOME BUYERS/OWNERS GUIDE TO LOG HOMES for complete details about log home types, construction methods, inspection procedures, common defects.

See SLAB LOG CABIN SIDING for a description of conventionally framed homes with a log-exterior.

Also see LOG HOME CONSTRUCTION for a brief description of this construction method.

Our complete list of log-home information, inspection, diagnosis, repair, construction, articles is at LOG HOME GUIDE

Masonite™ and other hardboard Sheet and Siding Building Materials

Masonite hardboard © Daniel Friedman at

(History & dates in process, contributions invited)

Our photo (left) shows the back side of an early hardboard interior-use product labeled "Genuine4 Masonite Quartrboard".

See these related and contrasting materials:

OSB - Oriented Strand Board Roof and Wall Sheathing Materials

OSB Oriented strand board roof sheathing © Daniel Friedman at

Details about the properties of OSB are at OSB - Oriented Strand Board. Also see DEFINITIONS of ENGINEERED WOOD OSB LVL etc. Excerpts are below.

Our photo (left) shows oriented strand roof decking (OSB) from the attic side, in new construction. Developed in the 1980's, oriented strand board is an engineered wood product in which strands and flakes of wood are cut from straight, low-knot small-diameter logs, usually aspen or white birch.

What is the difference between waferboard and OSB?

OSB is a modern wood product that developed from earlier 1970's "waferboard" product. In 1990 the Structural Board Association was formed. By 1996 there were 38 OSB producers in North America.

Unlike waferboard whose composite wood chips were place randomly, an oriented strand board product is made from wood chips that are deliberately oriented with respect to one another to provide greater strength.

See SHEATHING, OSB for more details and photo examples of OSB Oriented Strand Board sheathing use.

CONTACT us to contribute photographs of waferboard or OSB.

Plywood Sheathing on Walls & Roofs: Use in Building Construction, History, Description, Identification

Fire retardant plywood and OSB roof sheathing © Daniel Friedman at

Details about plywood building materials are at PLYWOOD Roof, Wall, Floor Decks & Sheathing.

Also see MDO Plywood and HDO Plywood

at DEFINITIONS of ENGINEERED WOOD OSB LVL etc. Excerpts are below.

PLYWOOD Roof, Wall, Floor Decks & Sheathing (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.

Our photo (left) shows both fire-retardant plywood roof sheathing (left half of the photo and center top and bottom) and OSB roof sheathing (center of photo and right edges of photo).

While modern plywood products use a variety of glues, heat, and pressure to produce the product, plywood has been around at least since 3500 BC when a glued-veneer version was produced in Egypt.

The rotary lathe (ca 1850) made modern plywood possible by cutting large sheets of wood from logs. The sheets are at right angles to one another and glued together using interior or exterior-rated structural adhesives. Interior plywood is generally glued with urea formaldehyde based glues; exterior plywood and marine plywood use phenolic formaldehyde glues and are water resistant.


Floor & Roof Truss Materials used in Building Construction

Details about wood roof and floor trusses are found at TRUSSES, FLOOR & ROOF. Excerpts are below.

Wood Floor & Roof Truss Photos

Truss example © Daniel Friedman at Truss example © Daniel Friedman at

Our photos show an attic view of modern roof trusses (above left) and floor trusses (above right).

Truss uplift, a cosmetic not a structural defect, is discussed separately at TRUSS UPLIFT, ROOF

Metal Floor & Roof Trusses

Details about metal roof and floor trusses are found at TRUSSES, FLOOR & ROOF. Excerpts are below.

Steel roof trusses do not "rot" of course, but they too are vulnerable to damage from water, leaks, and rust.

Truss example © Daniel Friedman at Truss example © Daniel Friedman at

Below our photo shows steel I-joists used in floor structures.

Steel web Truss example © Daniel Friedman at

Also see  I-JOISTS, Wood Roof Floor


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.

(History & dates in process, contributions invited)


Continue reading at FRAMING METHODS, Age, Types for the history and date ranges of various building framing methods or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see AGE of a BUILDING, HOW to DETERMINE - home page




Or see SAW & AXE CUTS, TOOL MARKS, AGE for additional building age clues likely to be available when examining building framing materials.

Or see this

Framing Material Article Series

Suggested citation for this web page

FRAMING MATERIALS, Age, Types at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


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