What Kind Of Plaster Is Used To Repair Plaster And Lathe

Plaster Types & Methods in Buildings
Plaster Ceilings, Plaster Walls & Plaster Blazon Identification in buildings

• Mail a QUESTION or Comment virtually how to identify dissimilar types of interior wall & ceiling plaster installation methods

InspectAPedia tolerates no conflicts of interest. We have no human relationship with advertisers, products, or services discussed at this website.

Types of plaster walls & ceilings:nails

Here we provide a photo guide to identifying types of plaster ceilings and walls installed in buildings, using building ceilings equally a photograph and investigation guide.

In this article serial we describe and hash out the identification and history of older interior building surface materials such plaster, plaster lath, split wood lath, accordion lath, sawn lath, and expanded metal lath, Beaverboard, and Drywall - materials that were used to form the (usually) not-structural surface of building interior ceilings and walls.

Synonyms for "plaster" include stucco, return, lime plaster, cement plaster, gypsum plaster, and plaster of paris. Lime plaster is also the principal ingredient in whitewash often used on building rock walls both indoors and exterior and also sometimes applied to wood surfaces.

Nosotros likewise provide an Commodity INDEX for this topic, or you can endeavour the page top or bottom SEARCH BOX every bit a quick way to detect data yous need.

Guide to Methods & Types of Plaster Ceiling & Wall Roofing Systems in buildings

Photograph Guide to Types Interior Plaster: carve up woods lath, sawn wood lath, expanded metal board, "rock lath" or plasterboard, drywall, & tainted Chinese drywall.

Our page top photo illustrates a thin plaster coating over woods lath in tardily 18th century dwelling house. When only a thin plaster glaze was applied, equally may be the case in an cranium or on a basement ceiling, the woods lath strips are clearly telegraphed equally the plaster dries and hardens.

Our stunning and stark photo of a sparse coat of plaster on gypsum lath illustrates a much afterward innovation for finishing edifice interiors. All of the modernistic plaster systems are discussed in this article serial.

[Click to enlarge any paradigm]

Article Series Contents

• PLASTER TYPES & METHODS in BUILDINGS
  • PLASTER Blanket LAYERS
  • FIBERBOARD PLASTER BASE SYSTEMS - divide article
  • GYPSUM BOARD Rock LATH SYSTEMS
  • Metallic LATH PLASTER LATH SYSTEMS - carve up article: expanded metal lath used beneath plaster indoors & on exteriors
  • MASONRY SURFACE PLASTER
  • PLASTER & GYPSUM BOARD HISTORY & RESEARCH
  • PLASTER REPAIR METHODS
  • SACKETT Board
  • WOOD Lath for PLASTER or STUCCO - separate article: hand-split board, squeeze box lath, sawn lath, mud-harbinger mix plasters
• PLASTER ASBESTOS CONTENT
• PLASTER BULGES & PILLOWS
• PLASTER Grit EXPOSURE HEALTH HAZARDS
• PLASTER INGREDIENTS, MIX, COMPONENTS
• PLASTER Lath, METAL
• PLASTER, LOOSE Autumn HAZARDS
• PLASTER Blazon IDENTIFICATION

This article includes a photo guide to split wood lath, pit-sawn lath, circular blade sawn wood board, expanded metallic lath, "stone board" or plasterboard, drywall, & tainted Chinese drywall discusses the types of plaster ceiling & wall coverings used in buildings, giving a history and description of types of materials used.

We include a description of plaster system identification and history of employ of plaster, a photo guide to plaster coatings, cracks, hazards, and plaster ceiling collapse hazards & photographs.

Reader Question: how to recognize types of plaster board or plaster lath used in buildings

I am not sure if you can help. I have looked up information online and can non find whatever. My abode was built in 1922. I have stripped wall paper that was hung in 1959. Nether the paper I thought id find board and plaster. Not so much. The look is that of sheet rock simply at close inspection information technology is more like concrete.

Like mortar I guess. You tin can scrape it away and it comes off like sand. It seems thick maybe 1/ii inch. I am wondering what it is and is it dangerous. The walls are all in excellent shape with small patch work. My grandparents lived hither since information technology was built both lived long healthy alive. But you lot never know. Any info would be helpful. Cheers. - B.D. 6/19/12

Respond: tips for decoding a cross-sectional cut of wall covering to disclose plaster, plasterboard, gyprock etc.

Our photo (above left) shows layers of wall finish material in a masonry block dwelling house: 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, modernistic drywall

But normally one cannot run into these layers of material except where there is a cantankerous-exclusive cut into the wall.

See FIBERBOARD PLASTER Base of operations SYSTEMS for a clarification of how fiberboard was used as a plastering base of operations.

A competent onsite inspection by an skillful unremarkably finds additional clues that aid accurately diagnose a trouble material in edifice interiors. That said, here are some things to consider:

I'd need to encounter photos and perhaps a sharp photo of a test cutting through the wall material to accept a more confident view of how your wall was constructed but

• Y'all may have a abode that used plasterboard (or gypsum board) as a lath arrangement to support a finished plaster wall. Plasterboard with holes in information technology was used as an alternative to forest lath or expanded metal lath to support finished plaster walls in homes congenital from the 1920-s to 1950'due south or even a bit subsequently.
• Asbestos was sometimes used in plaster, and certainly in joint compounds and in some finish textured paints. Even without asbestos, plaster and drywall dust tin exist a respiratory irritant or hazard, making steps to minimize dust and to command where it goes important, along with proper personal protective gear.

If all that's needed are minor repairs to the cease 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 like a radioactive material - it does not emit harmful particles unless it is disturbed. In a home of this historic period it would exist reasonable to treat these materials as Presumed Asbestos Containing Materials (PACM) as well as to presume that atomic number 82 paint hazards are present.

Wood Lath Plaster Systems from 1600 A.D. to Present

Plaster-type coatings practical over wood lath or directly onto masonry surfaces is at least 2000 years old. We provide details of wood-board plaster systems

at Forest LATH for PLASTER or STUCCO - split up article: manus-split board, accordion lath, sawn board, mud-straw mix plasters

This page illustrates several generations of plaster mixtures, types of wood, metal and gypsum board lath, board nails, drywall nails and screws and related materials used in buildings in recent-centuries.

Studying the details of plaster and its lath or other support system in a edifice tin can help decide the age of the structure.

Our photograph shows rough sawn and some hand split wood lath from Brinstone Farms in St. Weonards, Herefordshire, U.G. The lath is nailed with hand-wrought nails. This Herefordshire building and others in the area date from the early 1600s.

Nosotros name and illustrate these and talk over their periods of use below as an aid in finding out how old a building is and tracing its history. Examples:

• Mud used every bit a plaster over carve up woods board or woven wood lath. An example of mud plaster is beneath in this article

  at MUD PLASTER

• Horsehair mixed with plaster or cement for building exterior wall roofing.

  A photo of equus caballus hair in plaster is

  at PLASTER INGREDIENTS, MIX, COMPONENTS

• Plaster of paris applied in at to the lowest degree two layers, a rough brown or scratch coat and a smooth white plaster top coat over paw separate forest lath;
• Hand-mixed plaster scratch coat and finish glaze, diverse formulas of gypsum / plaster
• Plaster applied over "rock lath" or over Sackett Board, or over fiberboard: various board type substitutes for wood or metal lath systems - these are illustrated in detail beneath.

Also see DRYWALL, FIBERBOARD, PLASTER INTERIORS where we include photographs of not-plaster interior wall and ceiling coverings including drywall, beaverboard, and paneling.

For plaster type surfaces used on building exteriors,

meet STUCCO WALL METHODS & INSTALLATION.

Plaster on Lath Coatings or Layers: iii-coat & two-coat plaster systems

Our plaster wall and ceiling photos below demonstrate the stages in amalgam an traditional plaster on lath surface. The chief differences between 3-glaze plaster and ii-coat plaster systems are the inclusion or omission of the second intermediate coat that we discuss below.

Mud Plaster

Below we illustrate the plaster ears of mud-plaster used on woods lath strips, seen from the wall cavity side.

The mud plaster in this case was but a mud-straw mix of "plaster" base coat used in a belatedly 18th century New York habitation, ca 1785.

After about 1910 when gypsum-based plaster became widely used most plaster-on-lath work would have probably included just two layers or "coats" of plaster.

Three-coat Plaster organisation

Three-glaze plaster was applied in three layers from most-coarse to most fine.

When applied over forest lath or later, metal lath, the first coat of plaster, the chocolate-brown coat or scratch coat, is pushed through openings in the board so that when it hardens information technology is mechanically secured to the building wall or ceiling.

Below is a photo of the base coat of plaster viewed from the other side of a hand-split lath wall in a pre-1900 home I restored.

The base of operations coat was very fibroid and was referred to as a scratch coat or brown coat. Sometimes in attics and basements just the chocolate-brown coat or scratch plaster coat was applied, which is why I was able to take the photo shown just below.

The gouges or scratches in the dark-brown coat were made past the plasterer using a notched tool or saw-tooth-edged tool to ameliorate the adhesion of the next coat. The get-go two plaster coats would each exist nigh three/8" thick while the concluding coat was quite thin, merely 1/eight" in thickness.

Our plaster scratch glaze or "brown glaze" photo (below) shows how this surface was sometimes scarified to provide meliorate adhesion of the top coats of plaster.

However often the chocolate-brown coat was only applied roughly without gouging, as we show in this extra plaster crude coat photo [Image file].

The second coat of plaster in a three coat system was used to bring the surface of the finished wall frontwards and add thickness before applying the thinner, smoother finish coat.

Our photo at below left shows a common practice in roughly-finished attics: simply a thin skim glaze of plaster was applied directly to the wood lath - you can see the wood lath telegraphing through the plaster coating. Very often plaster cracking follows the lines of these lath strips.

In a 2 or three-glaze plaster organisation the final top glaze was intended to be troweled smooth and typically would have included the highest lime or gypsum content of the 2 or 3 layers. Typically the elevation coat is just 1/8" thick.

Spray-on plaster coatings, widely used equally a fireproofing in ships and buildings were more than likely to include asbestos likewise as rock wool, vermiculite, and fiberglass.

Asbestos was been used in other plaster preparations too. Spray-on plaster ceiling coatings beginning much later on (perhaps in the 1960'south [commendation needed] included styrofoam or similar beads or fragments.

Using Fiberboard Sheathing as a Plaster Base

Celotex and other brands of fiberboard sheathing were used both as exterior wall capsule and as interior wall sheathing or as a base for plastering as we depict below. This fiberboard is a cellulose product, non asbestos.

Above: excerpted from a photo provided by a reader who was renovating a North American dwelling house built ca 1930, we see fiberboard-gypsum panels used as a plaster base.

[Click to enlarge whatsoever image] Fiberboard pre-laminated to gypsum was sold in sheets in several thicknesses for employ as a plaster base of operations.

Separately, fiberboard, including Celotex™ was besides sold in raw fiberboard form for use as a plaster base, without pre-lamination of the fiberboard or pre-coating of it with gypsum.

These fiberboard sheets were lighter, easier to send, and less frail than the fiberboard-gypsum laminate product we show but to a higher place. Celotex provided detailed instructions for using their fiberboard equally a plaster base of operations. Y'all can see those details but beneath on this page.

Details well-nigh the types and uses and installation instructions for fiberboard-based and fiberboard-plaster-laminate based plaster systems are

at FIBERBOARD PLASTER BASE SYSTEMS.

More than near fiberboard products used as exterior and interior capsule as an insulating board is

at FIBERBOARD Sheathing IDENTIFICATION.

If you lot are worried almost possible asbestos contamination in fiberboard capsule or in fiberboard-gypsum laminate boards used every bit sheathing or as a plaster base,

see SHEATHING, FIBERBOARD ASBESTOS CONTENT

Our photo in a higher place shows a round cross department examination plug we cutting from a finished interior wall in an older home. Oldest materials are on the correct side of the plug. From left to correct we see

• Modernistic drywall (at leftmost side in the photo)
• A layer of plaster, or a pre-laminated plaster+Insulating gypsum-lath board comprised of a layer of forest or paper cobweb insulating board that has been bonded to the plaster layer.

More Manufactures Virtually Fiberboard Sheathing & Fiberboard Plaster Base of operations

• FIBERBOARD PLASTER BASE SYSTEMS - plaster systems using interior fiberboard or fiberboard pre-laminated with gypsum
• FIBERBOARD SHEATHING - home
• FIBERBOARD SHEATHING IDENTIFICATION - includes other examples of fibreboad-plaster systems also as other soft-lath or paper-board plaster base of operations products.

Gypsum Board Lath Sheets Used for Plaster Walls & Ceilings = Rock Lath, Plaster Lath, or Rock Lathe

Hither we will illustrate several types of gypsum board lath or "rock lath" and nosotros as well illustrate awarding of plaster over fiberboard sheathing, including both perforated and solid gypsum lath over which plaster was applied.

Perforated Gypsum Board Lath

Our photo (above) shows perforated gypsum lath panels that were used as plaster lath. Both perforated and solid gypsum lath panels were sold for utilize as a base for terminate wall and ceiling plaster.

Plasterboard with round holes punched at regular intervals substituted for the plaster scratch coat, nailed to wall studs, eliminating the woods lath requirement. A top coat of plaster was applied to the plaster board. "Ears" of oozing plaster pushed through the circular holes helped hold the plaster top coat in place

Our wall cross section cutaway photograph of gypsum board board installed on a New York home (photo at left) shows how these walls are constructed, and you can see quite clearly the top coats of plaster that were applied over the gypsum board itself. [Click any prototype for an enlarged, detailed view.]

Here is another photograph of a plaster wall test cut [photo] that shows a closeup of the layers of plaster board and pinnacle coats that make up the wall surface in a 1930's-built home whose plaster-board lath included wood fiber reinforcing materials.

Gimmicky gypsum lath products include GoldBond® brand gypsum board products including Kal-Kore brand plaster base panels sold by National Gypsum Corporation. Kal-Kore plaster base panels are designed as a base for veneer plaster, but these can also be used as basecoat plasters for Gypsolite, Two-Way Hardwall (National Gypsum products) or other conventional plasters.

Kal-Kore plaster base is sold in four' and viii' widths and in 8' to sixteen' lengths - considerably larger than the older plaster-board lath systems shown higher up and just below where nosotros describe regular rectangular bulges in plaster ceilings and walls.

Board lath and how information technology is applied are described in Plastering Skills, F. Van Den Branden, Thomas L. Hartsell, and in Usa Gypsum's Gypsum Construction Handbook [book for sale link] also equally other publications. VanDenBranden/Hartsell explain the popularity of board lath as a plaster base of operations [paraphrasing]:

• Board lath is rigid, strong, stable, and reduces the possibility of clay filtering through the mortar to stain the surface
• Board board is insulating, strengthens the framework of the construction, and the gypsum board is fire resistant
• Board board requires the least corporeality of mortar to cover the surface

Gypsum Board Board is provided in a variety of sizes, thicknesses, and types, most usually 3/8" x 16" x 48" in dimension, solid or perforated with iii/iv" diameter round holes punched 4" o.c. to provide mechanical keys, improving adhesion and burn rating of the surface. Our photo (in a higher place) shows mortar passing through the holes in perforated lath lath.

Here is some other example of perforated gypsum board plaster lath or rock lath, taken from a 1945 Greenville S Carolina home, courtesy of reader - 2022/11/03 Stephanie F. Nichols, Greenville SC

Picket out: only gypsum mortar can be practical over gypsum lath. Never employ lime mortar, portland cement, any other kind of binding amanuensis to gypsum lath.

See PLASTER BULGES & PILLOWS.

Also, perforated board lath should not exist used on ceilings where it is supported but at edges, because the perforations weaken the lath.

Simply this is not the merely type of plaster lath board or gypsum lath board found in homes. Higher up the product includes an insulating layer of upwardly to 1/2" of woods or paper cobweb insulating board on its innermost layer.

That layer is placed against the wall studs or in a masonry edifice confronting the masonry wall.

Insulating gypsum board plaster boards (not shown here) are similar to the gypsum board lath discussed above, merely include aluminum foil laminated to the wall or ceiling cavity side of the board. Installed with a 3/4" air infinite before whatever ensuing insulation, this material adds well-nigh the same R-value equally 1/2" insulating lath.

Solid Gypsum Lath Lath or Rock Lath

Solid gypsum lath products: gypsum-based fire-resistant tiles were first produced past The states Gypsum in 1916, a predecessor of paper-covered gypsum board used every bit a plaster board base and later in lighter form as mod drywall. U.S. Gypsum, formed in 1902 by the merger of 30 independent gypsum rock and plaster manufacturers, produced Pyrobar in 1903, a gypsum-based fireproof tile.

USG's get-go gypsum board product was Sackett Board described just to a higher place.

Below are photos of Certain-teed Products Corporation's Beaver Gypsum Lath, "Fire-Proof", including a nice edge view of "rock lath" or gypsum board used as a plaster base, courtesy of InspectApedia.com reader Z Headman & Zach, posted originally

at DRYWALL IDENTIFICATION STAMPS,

...

Solid gypsum board (to a higher place without holes) was also used every bit a support for a plaster finish coat. Often this material was practical in two-foot widths - a feature that the inspector may spot past noticing scalloped ceilings and walls or even cracks that announced regularly on 24" centers.

Below: rock lath / plasterboard lath / gypsum- lath (all synonyms) in a 1940'southward home in Poughkeepsie, New York. [Click to overstate any paradigm]

While cutting an opening in the habitation's interior wall to provide repair access to bath tub plumbing we could come across the cross department of this textile showing the thick plaster applied to the wall exterior. This is a more-normal awarding than the thin-plaster on gypsum board shown simply below.

Beneath: very thin-glaze plaster on more-contempo gypsum board.

Our gyp-lath photo merely above illustrates a simpler product installed on interior walls where no insulating layer was desired.

The gypsum-lath board (at left in the photograph is fabricated of gypsum covered on both sides by paper - there is no insulating board layer. Yous can run across the very thin layer of terminate-coat plaster on the right side of this gyp-lath board.

Question: What type of plaster ceiling do I take?

...

I've searched the internet and am trying to determine which type plaster ceiling I have in my master sleeping accommodation that collapsed. (see attached pictures) The insurance visitor has denied coverage and due to the Covid-19 pandemic the insurance company asked me to ship them pictures.

The insurance company claims it is was a faulty installation and seem to be hanging their hat on 1 of the pictures showing a staple.

There are also pictures that show some nails. As an FYI, the dwelling house was built in 1962.

The 2 questions I have are:

1. What type of plaster ceiling do I have?
2. Were staples and nails used in plaster ceilings during the early 1960'south?

Thank you so much, Anonymous by private e-mail 13 June 2022, Northridge CA

Moderator reply:

That'due south called a stone lath ceiling. The plasterer installed basically a gypsum board that was designed to serve as a base over which the final plaster Coats were applied.

Rock lath was a faster substitute for traditional wooden lath strips. I have not encountered rock lath nor other plaster lath installed with staples.

I have found no prohibition of use of staples for fastening drywall nor plasterboard provided a staple with proper crown width and thickness is used, and some drywall installation instructions might include staples along with drywall nails and drywalls screws equally acceptable fasteners, though staples are not a fastener I'd cull first for that purpose.

I prefer a larger fastener head and a more than-secure fastener. The thin caput of a staple is more-easily over-driven to create a weak connexion between plasterboard or drywall and the edifice frame, and the thin legs of the staple accept less withdrawal forcefulness than a drywall spiral and probably less withdrawal strength than a drywall boom.

The give-and-take "Staple" does non appear in USG's drywall installation instructions, not in CertainTeed'south drywall instructions, nor in those from Lowes nor Home Depot, all of whom recommend utilize of drywall screws.

USG's Sheetrock™ installation instructions recommend:

Type W Bugle Head Screws attach singlelayer gypsum panels to wood framing. Screws provide greater property power than wallboard nails, minimize popping and assist prevent impairment to the panels.

You're in Northridge where convulsion activity has shown itself thoroughly capable of loosening or damaging plaster ceilings and walls regardless of the type of fastener used.

Run across details

at Earthquake DAMAGE PHOTOS CA 1994 where we mail service photos of impairment I inspected after the 1994 quake that decimated Northridge Meadows and other areas.

Besides see

• DRYWALL INSTALLATION Best Practices
• DRYWALL INSTALLATION HORIZONTAL vs VERTICAL

Sackett Board mutli-layered gypsum / paper board - the commencement "drywall"

Patented as early as 1894, Augustine Sackett's paper-coated plasteboard provided a fast, economical means of covering interior walls and began a slow shift away from reliance on wood lath for plastering systems.

Past 1908, Kane Friedman, (afterward known equally F.L. Kane) along with Blumenfeld and Strimban were also credited with development of plaster board as nosotros cite below.

The Friedman (no relation to the web author Daniel Friedman) patent describes plaster board structure in the early on 1900s as beingness fabricated upwards of from eight to x layers of paper and plaster, much like the plasterboard shown in our photograph provided by InspectApedi.com reader Haniacek.

Friedman et al. patented a similar multi-layered plaster board to which a flexible metallic layer was added to let angle to form plasterboard around a curved radius.

In at least some instances layers of paper and plaster were bonded using coal tar pitch, and included thin canvas metal reinforcement.

These plaster boards were not intended to provide a finished surface.

Boards-of this character should non be used to make a finished wall, a dressing or surface of ordinary plaster being relied upon for the finished surface. - Friedman 1908

[Click to enlarge any image]

Sackett Board, outset produced by Alexander Sackett, who formed the Sackett Plaster Lath Co. became then widely-used that the term "sackett board" became rather generic, as we read in construction articles and in afterward patents by various inventors.

Please run across details

at SACKETT BOARD

Masonry Surfaces (Brick, Stone, Concrete) as a Plaster Base

As Van Den Branden and Hartsell detail, "masonry walls are about the oldest grade of plaster base known".

Thick coats of lime-based mortar were practical to very crude surfaces to plaster or "stucco" the building exterior or interior surfaces for many centuries earlier anyone thought of foam-board based EIFS blazon systems.

Run across SIDING EIFS & STUCCO

The authors continue to explicate that considering modern masonry wall exteriors are much more than smooth (film brick or physical cake walls), thinner coatings of mortar are used. The authors define three types of masonry bases for plaster, whether indoors or exterior:

Our photo (above, courtesy of Steve Goldstein) shows both rough and smooth brick and adobe surfaces on buildings in Guanajuato, United mexican states.

These masonry surfaces are regularly plastered or stuccoed with lime based cement mixtures and should exist considered high suction masonry bases every bit we describe beneath.

1. Low suction masonry bases for plaster: glazed tile, hard burnt brick surfaces, route or paving bricks, difficult stone such as granite
2. Medium or average "suction" masonry bases: "cinder block", concrete block, face brick, medium-hard brick, hard clay partitioning tile, improve grades of common brick, and some softer stone surfaces.

   See too CLAY HOLLOW TILE CONSTRUCTION

3. High suction masonry bases: soft common brick, soft clay sectionalisation tile, gypsum sectionalization tile, some highly porous tile surfaces.

   For completeness one should add a quaternary plaster surface blazon:

4. Concrete surfaces every bit a plaster base: these surfaces provide special problems for plaster application and need to be especially prepared (scratched), or must be plastered using a special loftier-adhesive bonding plaster, or coated with a primer that is approved for bonding the plaster to the concrete

Encounter STUCCO WALL METHODS & INSTALLATION for details about exterior stucco wall systems.

History of Invention of Gypsum Board, Perforated Board, Push Board as a Plaster Base of operations or Plaster Lath System

Van Den Branden and Hartsell list ten gypsum board lath products, hither we provide the full list

1. Gypsum lath board - discussed above - run across also SACKETT Board
2. Long length insulating gypsum lath
3. Veneer plaster gypsum lath
4. Radiant oestrus gypsum lath plaster base of operations
5. Gypsum wallboards
6. Gypsum backer boards
7. Coreboard
8. Gypsum studs
9. Gypsum sound-irksome backer lath
10. Insulating board board - discussed to a higher place

Patent disclosures give a general idea of the years of first popular use of gypsum lath as a plaster lath base. We encounter that in Due north America plaster board lath was in use at least before 1918, condign more widespread in the 1920s. Utzman in 1925 described "gypsum lumber" every bit a plaster base of operations.

And Hicks, likewise in 1922, described plaster board with recesses or depressions to adapt gypsum board for utilise as a plaster base of operations.

Gypsum Board & GypRoc plaster base patent inquiry & history

The following citations are ordered by year of patent grant for gypsum board and gypsum board used every bit a plaster base.

• White, Alexander P. "Composite lath." U.S. Patent 1,276,147, issued August 20, 1918.

  Patent excerpts:

  Improvements in Blended Laths, of which the post-obit is a specification. This invention relates to a novel building textile to be used chiefly for lathing, and its object is to provide an improved and side thereof. cheaper article of this nature that tin can be readily handled and transported, and which possesses forcefulness without nifty weight.

  A special object` of the invention is to provide a composite lath construction having novel means for strengthening the product in combination with an artificial rock body element, while at the same time imparting thereto improved facility for absorbing and assimilating excess moisture in-such a manner as to concur the body of the lath to proper class and condition during the setting of the plaster, thereby insuring the drying of the latter with an fifty-fifty surface, both on walls and ceilings.

• Emerson, Joseph W. "Gypsum wall board." U.Due south. Patent one,439,954, issued December 26, 1922.
• Hicks, William D. "Lath." U.S. Patent 1,430,080, issued September 26, 1922.

  Patent excerpt: This invention relates to a lath and .especially pertains to a composition lath. It is the object of this invention to provide a lath in the form of a wall board adjusted to exist manufactured in comparatively large sheets and and so formed every bit to possess considerable rigidity and not bend in treatment and so reinforced as non to exist readily bro en.

  Another object is to provide a rigid composition slab or board having recesses or depressions on its outer face adapted to receive and form a key for plaster, and in which the recesses or depressions are so formed and arranged every bit not to materially weaken the board.

  ... to provide a combined wall board and lath to arrange it for use in forming either a polish wall surface in itself or every bit a lath to receive a finish' coating of plastic material.

• Brookby, Harry E. "Limerick wall lath and method of making the same." U.S. Patent 1,428,827, issued September 12, 1922.
• Brookby, Harry East. "Process of making plaster lath." U.S. Patent 1,511,500, issued October 14, 1924.
  Patent disclosure excerpts:

  This invention relates to improvements in building materials and more particularly to 'a light weight wallboard or plaster board, and is an comeback of the invention set up along in my prior Patent No. ane,428,827, dated September 12-, 1922.

  Fabricated plaster lath for some fourth dimension i has been used as a substitute for the customary wooden lath in buildings and plaster wallboard every bit a substitute for both wooden lath and plaster.

  The fabricated boards of this graphic symbol formed of a plaster body protected by fibrous cover sheets when used as wallboard or a substitute for both lath and plaster are usually of a larger size than the plaster board or substitute for the board alone and on account of the weight of the plaster body and increased size. usually 48 inches wide, of an inch thick and from to 10 feet in length, are both cumbersome and heavy.

  It is an object of this invention to provide a light. weight trunk for plaster wallboard with all the favorable characteristics and structural requirements of the present plaster wallboard but which will be easier to i handle in shipment and in awarding .upon the edifice, wall or ceiling, and which while not detracting from the force of the board volition greatly reduce the price of transportation.

• Utzman, Clarence W. "Wall construction." U.Southward. Patent 1,559,134, issued October 27, 1925.

  Excerpt: ... body having a fibrous-"covering" bonding, the gypsum boards contemplated in this invention may both be sawed and fitted in the same manner as their wooden construction here before mentioned a ... This invention contemplates the use of gypsum lumber [for the backing of' wall-. board the nature of which' board will permit the accomplishment of the above described objects.

• John, Schumacher. "Method of making plaster-board lath." U.S. Patent ane,589,569, issued June 22, 1926.
• MacDonald, Marylee. OLD HOUSE RESTORATION: PLASTER [PDF] (1984) Sometime Business firm Restoration OHR1 (2004). Building Inquiry Quango, School of Architecture, Univ. Illinois Urbana Champaign
• Buttress, George A. "Board lath." U.S. Patent 1,694,640, issued December xi, 1928.

  Extract: This invention especially pertains to aIl lath of the type embodying a panel consisting of a layer of plaster interposed between gristly facing sheets.

• SACKETT Lath - early history of plaster board products used as a plaster base of operations to supplant or replace forest lath systems.

Plaster Repair Methods, Resources, Standards

• ASTM C 842
• ASTM C 841 Metal Lath or gypsum lath installation
• Isham: "An Example of Colonial Paneling", Norman Morrison Isham, The Metropolitan Museum of Fine art Bulletin, Vol. 6, No. 5 (May, 1911), pp. 112-116, bachelor by JSTOR
• PLASTERING, [PDF] PM 5, Product & Systems Technology, U.s. Gypsum, May 1998, retrieved x.5.2010, original source: http://www.usg.com/rc/technical-articles/plaster/
  plastering-technical-guide-veneer-plaster-joint-reinforcement-systems-en-PM5.pdf Usa Gypsum Visitor, 125 Due south Franklin ST., PO Box 806278, Chicago, IL 60680-4124,
  Paraphrasing from this certificate:

  USG uses the term shadowing in this certificate in describing the visual effect over gypsum lath joints caused by the lower moisture absorption charge per unit (take-upwards) and lower capacity than gypsum base confront paper. Shadowing at joints occurs where veneer plaster is applied over record joints, requiring a second coat to completely hibernate the tape, providing a visually uniform surface. USG Advises: "This [2d] comprehend glaze must exist allowed to harden and dry out before plaster application is started.

• Gypsum Construction Handbook [purchase at Amazon.com] H17, Technical Folder SA920 and PM2, PM3 and PM4, United States Gypsum Company, 125 South Franklin ST., PO Box 806278, Chicago, IL 60680-4124,
• Plastering Skills [purchase at Amazon.com] F. Van Den Branden, Thomas Fifty. Hartsell, Amer Technical Pub (July one, 1985), ISBN-10: 0826906575, ISBN-13: 978-0826906571 [purchase at Amazon.com]
• Grimmer, Anne Eastward., The PRESERVATION & REPAIR of HISTORIC STUCCO [PDF], National Park Service Preservation Brief No. 22., retrieved 2022/06/18, original source: https://www.nps.gov/tps/how-to-preserve/briefs/22-stucco.htm
• METAL LATH SPECIFICATIONS, SPECIFICATION FOR Metal LATH AND ACCESSORIES, Lath AND PLASTER [PDF] from Amico, a lath and plaster accessory producer.
• Board & PLASTER SYSTEMS, [PDF] 092300/NGC, National Gypsum Lath and Plaster Systems, National Gypsum Corporation, 800-628-4662 describing National Gypsum's Kal-Kore brand plaster base of operations
• Gypsum Construction Guide, National Gypsum Corporation, 2001 Rexford Road, Charlotte, North Carolina 28211, Tel: 704-365-7300, Email: ng@nationalgypsum.com, Website: http://www.nationalgypsum.com
• MSDS: GOLD Bond® Make GYPSUM BOARD PRODUCTS, [PDF] plaster base, National Gypsum Corporation. Other drywall MSDS sheets are establish at Drywall MSDS.
• METAL Lath SPECIFICATIONS, SPECIFICATION FOR Metal LATH AND ACCESSORIES, Lath AND PLASTER [PDF] rom Amico, 3245 Fayette Ave. P.O. Box 3928, Birmingham, AL 35208, (205) 787-2611, (800) 366-2642 and in Canada: 1080 Corporate Bulldoze, Burlington, Ontario L7L 5R6, Canada, (905) 335-4474, (800) 663-4474. Amico is the largest metallic lath producer in North America. Website: http://amico-board.com/
• NPS, DETERIORATED PLASTER FINISHES - REPAIR STANDARDS [PDF], U.South. National Park Services, ITS No. nineteen, Interpreting the secretary of the interior's standards for rehabilitation, applicable standards, retrieved 2022/06/18, original source: https://www.nps.gov/tps/standards/applying-rehabilitation/its-bulletins/ITS19-DeterioratedPlaster.pdf
• NPS, REPAIRING HISTORIC Apartment PLASTER WALLS & CEILINGS [PDF], National Park Service, U.Due south. Department of Interior, Preservation Cursory NO. 21, retrieved 2022/06/17, original source: https://world wide web.nps.gov/tps/how-to-preserve/briefs/21-flat-plaster.htm
• Worsham, Gibson. "Exterior Plaster Restoration at the Lord Morton Business firm, Lexington, Kentucky." Association for Preservation Technology Bulletin. Vol. Thirteen, No. 4 (1981), pp. 2733

Reader Q&A - likewise come across the FAQs series linked-to below

@Dana, that wall area is simply a cement-grout mix used to seal the wall surface without its top layer if ceramic tile.

As long as your newe vanity covers that same surface area or larger you should be fine. If it doesn't let me know and I tin can describe another fill-in options.

Hello! My firm was built in 1957ish. I just removed a bath vanity only to observe that this was behind it. I am not sure what I am looking at? What do I need to do before installing a new vanity? Thank you very much for ANY tips!

Re-posting without disallowed advertising link:

Mikaela Flemington · 1 minutes agone
I wish more people would postal service valuable content like this. This plastering is the first time I've been on your website, but after this, I doubtfulness it will be the terminal time. - Lancaster Drywall Contractors Co.

Moderator annotate:

Thanks for the comment Mikaela; we welcome questions, criticism, content suggestions and we are happy to place and link to and give contact information for those technical contributors.

@Katharine Gibson,
Cheers very much!

Katharine

I can't quite make out your photo merely it's possible that what we are looking at is a fiberboard that was used as a plaster base. You don't have to apply that same cloth you lot can use drywall for repairs

How-do-you-do,
My husband and I tin't figure out how to repair our plaster wall. It doesn't look similar information technology was synthetic using wood lath method. Would you be able to tell us what type of plaster structure this is and the best method for repairing information technology? Thanks!
Katharine Gibson

That sounds similar rough-glaze plaster, peradventure a poor mix, or water damaged. Sorry just I can't identify the textile from text.

The ceiling in our cellar has wooden laths just, instead of plaster, there's grey crumbly dusty stuff which may perhaps accept once been some kind of mortar. At that place'due south a thick layer, about one-half-inch-or then above the laths & a sparse coat beneath, both very crude & uneven, like a desperately ploughed field.

It seems reasonably safe & secure, apart from a few random holes with broken laths, possibly where someone has accidentally bashed information technology while moving beefy things in & out of the cellar. It's only a cellar, which we hardly use at all, & I've got no DIY skill or cognition any, so I'one thousand definitely not going to mess with it across, um, filling the holes with Polyfilla. But I'1000 curious about the grey crumbly stuff -any idea what information technology might be?

Gypsum Sheathing Fire-Proof Board
In Ceiling, coated with another layer of Plaster
Does this incorporate Asbestos?

Vincent

Please find our discussion at present in the bottom of the commodity above on this folio.

You may need to clear or refresh your browser cache to see the updates.

Vincent

That's definitely a wood fiberboard product. It looks equally if the original finished wall in your home was fiberboard and that afterward someone installed modern drywall or gypsum board over-top of the fiberboard.

I've taken a few boosted pictures to add on to the one I sent 4 days ago, in case that helps.

Vincent, if it's soft it could be fiberboard.

See UNIDENTIFIED FIBERBOARD PRODUCTS

Hullo, I'm in the procedure of remodeling a bathroom in my business firm and I've discovered a strange mysterious board similar material backside the walls and the ceiling of the bathroom.

The board is like a mix between cardboard and particle lath, information technology's stiff and has a bit of softness to it (kinda crumbles when I cut it). The boards in the walls don't seem to be securely fastened to the studs.

A couple of them overlap in a section of the wall. There's also a adept amount of play in the wall (i.e. I can wiggle the lath front end and back a few inches).

There's also stuffed insulation backside the boards in the walls while in that location'south no insulation in the ceiling (the bathroom is on the 1st floor of a 2 story house).

I'd like to notice out what this fabric is and then I can find the best way to repair the walls and besides brand sure it's prophylactic to work with.
Thanks in advance.

Kerry

I would become help from a habitation inspector who has equipment to measure wet - we desire to be Sure that at that place is no ongoing leakage nor that wet plaster or gypsum board was left where information technology might harbor a nasty mold reservoir.

I agree that inadequate surface prep such as leaving dust or debris can lead to pigment failure, but your photograph looks to me like peeling pigment effectually a water stain.

If the problem with peeling pigment were inherent in the properties of perforated gypsum board lath used as a plaster base you would not see such a localized peeling problem.

Bottom line: look for a contempo or recurrent or seasonal leak.

Keep me posted, every bit what you find will assistance other readers.

We have a 1950s business firm that has Perforated Gypsum Lath Lath and I am wondering if this is what caused issues in the kitchen area when the business firm was remodeled (before we bought it). The paint on the ceiling in the kitchen keeps pealing.

We call up that there might have been a leak from the roof years ago from the looks of the staining now visible when the ceiling peeled. We just put a new roof on so that is not a problem any longer. Yet we don't know how to deal with the ceiling in there.

It keeps peeling. Are at that place any suggestions on it? I think the guys we bought the house from may have taken the texture off, just and then painted it with a bad selection of type of pigment. Any suggestions on dealing with this? This is also happening in the bath.

Something else to think about is that these houses in Western Colorado utilise swamp coolers in the summer to cool the houses which pumps a large amount of humidity in the firm in the dry summertime months. This might exist function of the problem also merely I don't think so.

If you lot have any ideas I would dear to hear them!
Prototype LOST by older version of Clark Van Oyen's useful Comments code - now fixed. Please re-post the image if you lot can. Sorry. G

Matt

What's the question. in your photo I come across

onetime knob and tube electric wiring (search this website for that phrase to read communication)

marks from a prior generation of wood board / plaster ceiling or wall (photo unclear)

Evidently more-contempo gprock or drywall

water leak stains

some diagonal lath capsule, incomplete

some sistering forth side a joist or stud (photo unclear)

wires hanging from a ceiling, perchance previously a suspended ceiling was here?

Permit me know.

Anyone familiar with the
Paradigm LOST past older version of Clark Van Oyen's useful Comments code - now fixed. Please re-mail the image if you lot can. Sorry. G

Pam:

Yes, there were some plaster patterns as well equally textured-paint patterns embossed on walls and ceilings using a condom or foam roller forth with a suitable soft-mix of plaster or gypsum chemical compound; some of those surfaces may comprise asbestos.

Is there any sort if plaster "stamp" that could reproduce this pattern in my math and plaster ceiling from 1960?
Epitome LOST by older version of Clark Van Oyen'due south useful Comments lawmaking - now fixed. Please re-post the image if y'all can. Sorry. M

Loose Plaster is Unsafe, Peculiarly Loose, Falling Plaster Ceilings

For a discussion of rectangular bulges, shadow furnishings, or scalloping in plaster ceilings or walls

see PLASTER BULGES & PILLOWS

See PLASTER, LOOSE FALL HAZARDS for examples of bulged plaster that may exist danger signs

Ingredients in Plaster Used in Buildings

This topic has been moved to PLASTER INGREDIENTS, MIX, COMPONENTS

Types of Forest Board Used for Plaster Ceilings & Walls

Details of wood lath plaster base of operations systems are given in this separate article:

WOOD LATH for PLASTER or STUCCO

More about using saw kerf marks and other tool marks on wood to decide the age of a edifice tin can be read

at SAW & AXE CUTS, TOOL MARKS, Age

Expanded Diamond Mesh Metal Lath for Plaster Walls & Ceilings

Details near metal lath and its history are found

at PLASTER LATH, Metal.

Details most exterior stucco using metal lath are

at  STUCCO WALL METHODS & INSTALLATION.

...

Go along reading at PLASTER INGREDIENTS, MIX, COMPONENTS or select a topic from the closely-related articles below, or see the complete Commodity Alphabetize.

Or meet PLASTER TYPES & METHODS FAQs - questions & answers posted originally on this folio

Or see these

Recommended Manufactures

• DRYWALL, FIBERBOARD, PLASTER INTERIORS - home
• PLASTER TYPES & METHODS in BUILDINGS
  • PLASTER Blanket LAYERS
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  • GYPSUM Lath Rock LATH SYSTEMS
  • METAL Lath PLASTER Lath SYSTEMS
  • MASONRY SURFACE PLASTER
  • PLASTER & GYPSUM BOARD HISTORY & Inquiry
  • PLASTER REPAIR METHODS
  • SACKETT BOARD
  • WOOD LATH for PLASTER or STUCCO
• PLASTER ASBESTOS CONTENT
• PLASTER BULGES & PILLOWS
• PLASTER DUST EXPOSURE HEALTH HAZARDS
• PLASTER INGREDIENTS, MIX, COMPONENTS
• PLASTER LATH, Metal
• PLASTER, LOOSE FALL HAZARDS
• PLASTER Blazon IDENTIFICATION
• PLASTER VENEER Best Practices
• PLASTERBOARD EXPANSION COEFFICIENTS
• STUCCO WALL METHODS & INSTALLATION - plaster type surfaces used on edifice exteriors

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