Plaster lath evolution

Paul Brubacher

In Memoriam
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296
Location
outside of Toronto, Ont
A couple of weeks ago I posted a message about how my father-in-law had built 2 houses after WWII.That finally got me wondering what he actually did himself and what he contracted out. I am certain that he did the framing, insulation, roofing and trim work. He probably also put up the plaster lath.

When I worked on construction in the mid 1960s, the lath was 48" x 16" paper wrapped gypsum. By the early 1970's, the lath had been replaced with dry wall, and only a few people still used the rough coat followed by a putty coat. The rough coat was actually sprayed on the walls in the 1970s.

At one time they used wooden lath, about 48" x 1.5" and the rough coat was reinforced with horse hair.

When did the changes from wooden lath to 48 x 16 and then drywall occur?
 
I would think there would be some regional differences. Around here, I see metal lathe in commercial buildings and then homes, starting probably late 40's (commercial) early 50's for residential. I would assume commercial first, for speed of construction (higher product cost for less labor).
I have a room my grandfather added in 1960, and I don't know if it was cost effective or just what was popular then, but instead of drywall or plaster, they used paneling. I've seen that on other houses of that vintage. (there could have been a shortage as well)
 
I'm not sure about specific timelines, it was likely highly regional[1]... Somewhere in the plaster->gypsum paper transition there was also the shift from lime and horse hair plaster to cement plaster around here that looks like it started happening around the turn of the last century, some buildings around 1890(ish) were cement plaster but the earlier ones sometimes I've found a bit of horse hair lime plaster residue. You can't really tell unless its broken off or you can see the backside of the lathe.

[1] The wikipedia article on drywall has a short history https://en.wikipedia.org/wiki/Drywall
  1. The first plasterboard plant in the UK was opened in 1888
  2. Sackett Board was invented in 1894 by Augustine Sackett and Fred Kane. It was made by layering plaster within four plies of wool felt paper
  3. Gypsum board evolved between 1910 and 1930 beginning with wrapped board edges and elimination of the two inner layers of felt paper in favor of paper-based facings

I also found a few articles saying that usage really took off in the post WWII building boom.

Talking to friends who have moved out here to the west coast from the east there is still a fair bit of cultural difference in how drywall is applied. The east coast applications tend (vast generalizations here) to have a skim coat (or possibly several) on top and perfectly flat/level walls. The west coast has embraced "textured" walls which are usually of the spray on/knock down variety. The smooth skim coat requires a lot higher level of skill because if there is any variation in wall straightness or skim application it really shows up whereas the textured surface hides a lot of sins. I'm guessing that this is a hold over from the lathe and plaster days on the east coast and the west coast had a lot more rough and ready construction so never really developed the culture.

Equally as interesting is looking for evidence of the transition of framing types from timber frame/modified timber frame to balloon to modern platform frame construction. Interestingly you'll see balloon framing techniques in some newer metal frame buildings (usually with fire barriers added between floors though unlike most of the old wooden ones..).
 
I'm also thinking the 48x16 was likely something called "rock lathe" and not "drywall" in the modern sense, the timeline mostly lines up. Everything I'm seeing claims that 1960's was around the tail end of the rock lathe period mostly everywhere.
 
Cedar lath was common here on the west coast of Canada through the 40's and 50's when it pretty well gave way to gyproc lath, the 16" x 48" and sometimes 24 ' x 96" stuff. Gyproc lath continued to be used right through the 70's and occasionally in the 80's. Starting in the mid 70's Veneer plaster started to become common. It is the skim coat applied over a board that has the same dimensions as drywall board but withe a more porous paper on the surface. It was developed in the UK around 1900 and was a finish used more for speed of application rather than quality of finish. You really can't straighten much with veneer nor can you obtain the high sheen of a properly applied 3 coat browning and putty coat finish. Drywall started to become popular here in the mid 50's.
I spent 45 years as an ornamental plasterer, a trade that that is pretty much dead.
 
It's interesting that most of the comments are that the dry wall is coated. Around here, at least the non luxury houses, the joints are taped and the screws covered, but no final coat is applied.

The contractor that I worked for in the 60s did both brick laying and plastering. Slaking the lime for the putty coat always involved inhaling the lime dust which would sting.

Some ceilings got fancy putty coats, raised edges and cove around the edges. Or circular swirls around a central light fixture. I can't remember what was used to build up the cove corners.
 
When I was building a computer center in the early 1970s, I was surprised that the building people put up wire lath, base coat, and finish coat plaster. WHY??? They said they could do it faster than sheet rock, since the taping compound dried slowly. The room was ready for painting in less than a day, so I guess they were right. I watched closely to learn how, and still have dry base and finish plaster that I occasionally pull out for repairs.
 
the skim coat board was commonly called blue board, and rock lath in our area was still being used regularly around the early 70's. quite often for a backer behind paneling,, which is basically non existent today,, used be stores that dealed exclusively in it.. fine wood grain and species.. i have seen it priced as high as 65 dollars a sheet for some fine stuff.. construction has changed since the old days:)
 
It's interesting that most of the comments are that the dry wall is coated. Around here, at least the non luxury houses, the joints are taped and the screws covered, but no final coat is applied.

Finish and coating are going to depend on how it is specified in the construction documents. There are five different levels to drywall finishing, most residential dry-wallers never go beyond level 2. Commercial jobs usually require more due to the expanse of some of the walls. For example, a level 2 finish on a long corridor in a hospital wouldn't work because the lighting reflected off the wall would make the tape seams more visible. I work for an architectural firm that does a lot of retail and other large commercial projects as well as medical/hospital projects and we rarely specify anything lower than a level 4 finish.

LEVEL 1 - Tape set in joint compound. Tool marks and ridges acceptable. Surface is free of excess joint compound.
Suggested use: Frequently specified in areas above ceilings, in attics, in areas where the assembly would generally be concealed, or in areas not normally open to public view. Some degree of sound and smoke control is provided. In some geographic areas, this level is referred to as "fire-taping". Tape and fastener heads need not be covered with joint compound.
LEVEL 2 - Tape embedded in joint compound and wiped with a joint knife, leaving a thin coat of compound over tape. Surface shall be covered by one separate coat of joint compound. Surface shall be free of excess joint compound. Tool marks and ridges acceptable. Joint compound applied over the body of the tape at the time of tape embedment shall be considered a separate coat of joint compound and shall satisfy the conditions of this level.
Suggested use: Specified where water-resistant gypsum backing board is used as a substrate for tile. May also be specified in garages, warehouse storage or other similar areas where surface appearance is not of primary concern.
LEVEL 3 - Taped as in level #2, then covered with two separate coats of joint compound. Joint compound shall be smooth and free of tool marks and ridges. Note: It is recommended that the prepared surface be coated with a drywall primer prior to the application of final finishes.
Suggested use: Typically specified in appearance areas which are to receive heavy or medium texture finishes before final painting, or where heavy-grade wall coverings are to be applied as the final decoration. This level of finish is not recommended where smooth painted surfaces, or light to medium weight wall coverings are specified.
LEVEL 4 - Taped as in level #2, then covered with three separate coats of joint compound. Joint compound shall be smooth and free of tool marks and ridges. Note: It is recommended that the prepared surface be coated with a drywall primer prior to the application of final finishes.
Suggested use: This level should be specified where flat paints, light textures or wall coverings are to be applied. In critical lighting areas, flat paints applied over light textures tend to reduce joint photographing. Gloss, semi-gloss and enamel paints are not recommended over this level of finish. The weight, texture and sheen level of wall coverings applied over this level of finish should be carefully evaluated. Joints and fasteners must be adequately concealed if the wall covering material is lightweight, contains limited pattern, has a gloss finish or any combination of these features is present. Un-backed vinyl wall-coverings are not recommended over this level of finish.
LEVEL 5 - Taped as in level #4. Surface shall be covered by three separate coats of joint compound. A thin skim coat of joint compound, or a material manufactured especially for this purpose, shall be applied to the entire surface. The surface shall be smooth and free of tool marks and ridges. Note: It is recommended that the prepared surface be coated with a drywall primer prior to the application of final finishes.
Suggested use: This level of finish is highly recommended where gloss, semi-gloss, enamel or non-textured flat paints are specified, or where severe lighting conditions occur. This highest quality finish is the most effective method to provide a uniform surface and minimize the possibility of joint photographing and of fasteners showing through the final decoration.
 
LEVEL 5 - Taped as in level #4. Surface shall be covered by three separate coats of joint compound. A thin skim coat of joint compound, or a material manufactured especially for this purpose, shall be applied to the entire surface. The surface shall be smooth and free of tool marks and ridges. Note: It is recommended that the prepared surface be coated with a drywall primer prior to the application of final finishes.
Suggested use: This level of finish is highly recommended where gloss, semi-gloss, enamel or non-textured flat paints are specified, or where severe lighting conditions occur. This highest quality finish is the most effective method to provide a uniform surface and minimize the possibility of joint photographing and of fasteners showing through the final decoration.

This was a finish that was used in high end projects here. I did quite a bit of it for certain contractors. We referred to it as glazing. After the final skim coat we would mix drywall primer together with finish mud to a fairly thick consistency and roll a coat over the entire surface with a course roller. When it dried it was hard and very slightly orange peeled. A light sanding knocked off any high spots. Two coats of the same material thickened a bit more would be applied, one going vertical and the other horizontal. The only sanding that would be done was done with a hand sander and a bright light. This stuff was very hard to sand so you made sure you got it right. It was as labor intensive as plaster and not many contractors would spring for the extra cost.
 
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