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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.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
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 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.
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.
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.
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.
Wooden wall paneling - tongue and groove pine and other woods
Wall paneling in 4' x 8' sheets
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
Frequently Asked Questions (FAQs) about building interior wall materials, surfaces, & finishes
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.
Questions & answers or comments about ages & types of wall & ceiling materials, installations & practices.
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