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AGE of a BUILDING - how to determine
AIR LEAK MINIMIZATION
AIR POLLUTANTS, COMMON INDOOR
APPLIANCE EFFICIENCY RATINGS
ARCHITECTURE & BUILDING COMPONENT ID
ASBESTOS IDENTIFICATION IN buildings
BASEMENT CEILING VAPOR BARRIER
BATH & KITCHEN DESIGN GUIDE
BEST CONSTRUCTION PRACTICES GUIDE
BOOKSTORE - INTERIORS
BRICK LINED WALLS
CABINETS & COUNTERTOPS
CARPETING, SELECTION & INSTALLATION
CASEWORK, CABINETS, SHELVING INSTALLATION
CATHEDRAL CEILING INSULATION
CEILING FINISHES INTERIOR
CEILINGS & WALLS, PLASTER TYPES
DRYWALL INSTALLATION Best Practices
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOOR TYPES & DEFECTS
FLOORING MATERIALS, Age, Types
HEAT LOSS in BUILDINGS
HOUSEWRAP AIR & VAPOR BARRIERS
HOUSE DOCTOR, how-to be
HOUSE PARTS, DEFINITIONS
HUMIDITY LEVEL TARGET
INDOOR AIR QUALITY & HOUSE TIGHTNESS
INTERIOR FINISHES, BEST PRACTICES
KITCHEN & BATH DESIGN GUIDE
LIGHTING, INTERIOR GUIDE
MAINTENANCE SCHEDULE & PRIORITIES
MOISTURE CONTROL in BUILDINGS
MOLD: A COMPLETE GUIDE TO MOLD
NOISE / SOUND DIAGNOSIS & CURE
ODORS GASES SMELLS, DIAGNOSIS & CURE
PAINT & STAIN SELECTION & PROCEDURES
PLASTER & BEAVERBOARD & DRYWALL
ROOF VENTILATION SPECIFICATIONS
SAFETY HAZARDS & INSPECTIONS
STAIN DIAGNOSIS on BUILDING INTERIORS
STAIRS, RAILINGS, LANDINGS, RAMPS
STUCCO WALL METHODS & INSTALLATION
SWEATING (CONDENSATION) on PIPES, TANKS
VAPOR BARRIERS & CONDENSATION in buildings
VENTILATION in BUILDINGS
WALL FINISHES INTERIOR
WATER ENTRY in buildings
WINDOWS & DOORS
WINTERIZE A BUILDING
Guide to beaverboard, drywall, plaster & paneling on interior walls: ages & types of finish materials used for interior walls & ceilings: here we provide a photo guide to identifying types of plaster, lath, Beaver board, Upson Board, and Drywall to help identify these interior building wall and ceiling coverings and as an aid in determining the age of a building. This article discusses the identification and history of older interior building surface materials such plaster and lath, Beaverboard, and Drywall - materials that were used to form the (usually) non-structural surface of building interior ceilings and walls. Our page top photo shows hand-split wooden lath backing for a plaster interior wall.
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History of Types Interior Plaster: split wood lath, sawn wood lath, expanded metal lath, "rock lath" or plasterboard, drywall, & tainted Chinese drywall
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.
Also see PLASTER TYPE IDENTIFICATION for a photo guide to different plastering systems used in buildings. See Sheathing Celotex Homasote & Other for a discussion of exterior wall sheathing fiberboard products such as Homasote® and Celotex® insulating roof, wall, and foundation board products. For plaster type surfaces used on building exteriors, see STUCCO WALL METHODS & INSTALLATION.
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:
Our photo (above left) shows perforated gypsum board panels that were used as plaster lath.
Solid gypsum board (above right, without holes) was also used as a support for a plaster finish coat. Often this material was applied in two-foot widths - a feature that the inspector may spot by noticing scalloped ceilings and walls or even cracks that appear regularly on 24" centers. See PLASTER TYPE IDENTIFICATION for details.
Our photo shows expanded mesh metal lath used as plaster lath support for ceilings and walls; this material was also used on building exterior walls to support a stucco finish.
Metal lath was on occasion used also to support poured concrete ceilings (shown here) - unlikely to provide adequate strength for a thick pour unless additional reinforcement was used.
Depending on building age we may find a mixture of multiple types of plaster support, wood lath, gypsum board lath, and metal lath.
Wall or ceiling or stucco crack patterns may follow the borders of metal lath segments, especially if the lath was not securely nailed.
see PLASTER TYPE IDENTIFICATION for details.
Our photos (above and below) show modern identification stamps or labels that may be found drywall products used for interior walls and ceilings. Also see additional drywall identifying number stamps found at Drywall Gypsum Board Used for Exterior Wall Sheathing.
Where there indoor environmental concerns or corrosion damage to electrical wiring, copper pipes, air conditioning equipment, etc. See CHINESE DRYWALL HAZARDS.
We also find gypsum board sheathing used on some roofs, believe it or not.
In some applications a water repellent paper was used to improve the product's durability, as we show in this wall cavity side photograph of identifying marks on gypsum board sheathing.
When gypsum board was used for exterior wall sheathing, as we show in this interior photo (above left), let-in cross bracing was required at building corners. The white paint on the wall cavity side of the gypsum board shown in this photo was added during building renovations to address water damage and to improve water resistance.
Notice the pair of wall studs in the left hand photo? That stud pair marks the abutment of two panelized wall sections in this building. The corner panels were built flat in the panelized home factory and measure just 1/2" under 8' x 4'. Larger 8' x 8' wall panels were also produced and were used for this home.
These details permit the conclusion that this home was constructed using pre-fab exterior and interior wall panels, all clad with gypsum board that was glued to the wall studs for extra strength. Our photo at above right shows additional bracing that was incorporated into the gypsum-clad wall panel bottom, along with an assembly wire.
Details of this panelized construction home are at Panelized Construction.
An example of a drywall/gypsum board identification number appear on this 1950's product shown at left. This is another example of gypsum board used for exterior wall sheathing.
Mold growth on the wall cavity side of drywall is common when there have been leaks into the wall cavity. Our photo (left) shows mold growth on the wall cavity side of gypsum board used as exterior wall sheathing on a 1960's condominium in New York.
See SAMPLING DRYWALL for more information about mold growth on drywall and gypsum board products.
The photographs above show two different gypsum board wall sheathing products that employ a textured paper surface. At right is a modern product found in a home built in the 1990's.
Early Colonial Wall Paneling & Wainscoting
Early colonial paneling is described by Isham.
A concise history of wall coverings in residential buildings, more photos, & dates in process, CONTACT us, contributions invited.
Shown at left, colonial style wall paneling in the historic Suffolk Resolves House (1774) in Milton MA.
Wainscot Wall Covering
Wainscoting or "wainscot" is a wood wall finish applied to the lower portion of a building interior, typically about three to four feet up from floor level, and usually capped with a chair rail and usually applied with board edge joints butted vertically as in our photo.
Traditional wainscot is constructed by nailing individual boards to the wall surface.
Modern "wainscot" panels are sold in 4' x 8' sheets and cut to fit, producing a beadboard surface that looks like traditional wainscot.
Wainscot is an old term, possibly from the 1300's, that in its contemporary usage derives from the British Wainscot, "a fine grade of oak imported for woodwork" - Merriam Webster.
In North America wainscot has been in use since the colonial era.
Our photo (left) illustrates beadboard type wainscot wall paneling in a Victorian home built in Poughkeepsie, NY in 1900.
Wooden wall paneling - tongue and groove pine and other woods
Wooden wall paneling made of individual boards, often tongue-and-groove common or knotty pine, was most often nailed vertically from floor to ceiling and finished with wall trim at both of those levels.
In North America solid vertical tongue-and-groove pine paneling on building interior walls was particularly popular from about 1945 through the 1960's.
Wall paneling in 4' x 8' sheets
By the 1970's in the U.S. and Canada, the use of solid tongue-and groove wall paneling was more often replaced by thinner 4' x 8' sheets of wood veneer paneling sections.
Shown at left is a typical thin plywood veneer type wall paneling installed in the 1970's. A concise history of veneer-type wall paneling in residential buildings, more photos, & dates in process, CONTACT us, contributions invited.
Beaver-board and Upson Board are a wood fiber product used as an inexpensive interior wall covering and draft blocker from about 1903 when Beaver Board was invented by J.P. Lewis in Beaver Falls, NY, to the 1950s, with its near-twin product Upson Board continuing in use into at least the 1980's.
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.
Readers should see Sheathing Celotex Homasote & Other for a discussion of exterior wall sheathing fiberboard products such as Homasote® and Celotex® insulating roof, wall, and foundation board products. There we also include photographs of insulating wallboard products that have been attacked by mold or insects.
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.
Beaverboard and other paper or fiberboard products were used for exterior wall sheathing, as we show in this photograph at left. More widespread and recognized are insulating board sheathing products discussed at Sheathing Celotex Homasote & Other.
How to Identify Beaver Board and Upson Board
Beaver Board was marked on the back of each sheet with an ink-stamped trademark and brand.
Upson board embossed its marking into the board itself, and a "Blue Center" runs through every piece of the board.
Examine a cross section of the board for this characteristic blue material.
Portions of this material were derived from Weaver.
Masonite hardboard panels are often found as a utility cladding in buildings on walls and ceilings. This article explains the utility usage of hardboard interior products, and we exclude wood or wood-like wall or ceiling paneling products. Those are discussed at History of the Use of Wood and other Wall Paneling in North America.
Also see Masonite™ used in strutures.
(History, more photos, & dates in process, CONTACT us, contributions invited)
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Frequently Asked Questions (FAQs) about building interior wall materials, surfaces, & finishes
Question: how to recognize types of plaster board or plaster lath used in buidings
I am not sure if you can help. I have looked up infor online and csn not find any. My home was built in 1922. I have stripped wall paper that was hung in 1959. Under the paper I thought id find lath and plaster. Not so much. The look is that of sheet rock but at close inspection it is more like concrete.
Like morter I guess. You can scrape it away and it comes off like sand. It seems thick maybe 1/2 inch. I am wondering what it is and is it dangerous. The walls are all in excellent shape with minor patch work. My grandparents lived here since it was built both lived long healthy live. But ya never know. Any info would be helpful. Thanks. - B.D. 6/19/12
Our photo (above left) shows layers of wall finish material in a masonry block home: concrete block at left, wood insert to secure window trim (removed for the photo), a wood fiber insulating board or "beaverboard" type material, a layer of plaster, layers of finish plaster and paint, and finally at right, modern drywall. But normally one cannot see these layers oif material except where there is a cross-sectional cut into the wall.
A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem material in building interiors. That said, here are some things to consider:
I'd need to see photos and perhaps a sharp photo of a test cut through the wall material to have a more confident view of how your wall was constructed but
If all that's needed are minor repairs to the finish wall surfaces and you are adding a patch not demolishing the walls, leaving the existing material in place is not itself a hazard. Asbestos is not radioactive - it does not emit harmful particles unless it is disturbed. In a home of this age it would be resonable to treat these materials as Presumed Asbestos Containing Materials (PACM) as well as to assume that lead paint hazards are present.
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