On Friday, we peeled plaster from the walls of the Blue Parlor, in the O’Kane Farmhouse. Scott was Bill and I, Ted, as we traveled in our proverbial telephone booth through layers of plaster, lath, wallpaper and time.
There were clues to some of what we might find. Surrounding the door openings were wooden strips, wedge-shaped in profile, that served as plaster grounds. They were a little over an inch thick, and were nailed four inches away from the opening itself, creating a border around the door opening that looked like a recessed casing. The application of these plaster grounds became popular in the mid-18th century, and allowed the plasterer to create a flat wall plane within the borders of the ground (Much of this initial dating information comes from James Garvin’s A Building History of Northern New England, pp 65-71). In most cases, the chair rail, baseboard, and door and window casings were applied directly to the frame, and served as the plaster ground. In Shaker buildings, for example, the casing is nearly flush with the plane of plaster. But in this wall, the plaster plane was an inch proud of the recessed door border, due to the applied ground, and there was a vertical, beaded joint between the side sections of the border and the top. It looked like a larger section of beaded paneled wall was peeking through.
As we carefully peeled the plaster from the lath, we paid attention to the composition of the plaster. Older plasters have a higher concentration of goat hair, and regularly one will uncover a multi-colored tuft that was was never fully mixed in. Older plasters were applied in three coats, a base coat, a straightening, or “brown” coat, and a skim coat. The base coat is thickly applied and creates the keys that lock the plaster onto the lath. The base coat squeezes through the slits between the pieces of lath, and droops behind. A skilled plasterer will use the right amount of pressure to create an even pattern of keys, enough pressure to create a key big enough to hold, but not so much that the plaster breaks off and splooges into the wall cavity. After the base coat has dried to a leather hard consistency, the brown coat is applied, and the plasterer drags a long straight-edged board, or screed, over the surface, flattening the wall plane between the grounds. The brown coat is usually where you see the most goat hair. The skim coat is the last, thinly applied coat, devoid of hair and leaving that hard, cured, eggshell finish. On the first two sections of wall, we found sawn lath behind the plaster, hung with machine-cut nails. This dates the added plaster surface to sometime after the mid-19th century, as we suspected (Garvin, p. 67).
Behind the lath we found beautiful, psychedelic wallpaper. The profile of beaded paneling telegraphed through, and punched vertical lines in the wallpaper at each panel’s joint. On the wall, one could see three different periods all at once. The horizontal shadow lines left behind by the lath, the lively geometric pattern of the wallpaper, and the vertical beads poking their noses through the surface.
So I liked that, but the most exciting discoveries were yet to come. So far, all we could determine in terms of dates was that the plaster was applied before the advent of wire nails during the late-1800’s, leaving no real indication of the date of the beaded paneling. Farther along the north wall, to the west, was a section that appeared to have once been partitioned off into a different room (according to a long joint in the floorboards). When Scott began dismantling this section, the wall cavity was different. There was a void behind the lath, and in its depths he could see the horizontal, bevelled profile characteristic of feather-edged paneling, and shiny, chrome yellow paint. The paneled wall he uncovered was was hung horizontally, and it had a feather-edged profile, where the edge of the board is beveled to a thin tongue that slips into a groove on the adjacent board. Conversely, beaded tongue and groove has a bead with an edge perpendicular to a quarter inch tongue. The joints in such boards are typically tighter. Both styles were used and re-used during the first half of the 18th century, but the feather-edged stuff is reminiscent of an earlier era.
Across the face of the older, yellow paneling, we saw the regular shadow lines of shelving, leading us to believe that this section of wall had been obscured by pantry storage and left alone when the rest of the room was upgraded. The wall plane of the beaded section is sufficiently proud of the feather-edged wall plane that the beaded paneling could be hiding more yellow feather-edged paneling–but this is only one of a number of possible scenarios. The beaded paneling could be contemporary with the feather-edged paneling; the feather-edged paneling might have been recycled from elsewhere, or simply used to delineate a different room in the house. In most homes, we’d never know the answer to these queries, because we wouldn’t dismantle the wall any more than was needed to make repairs, but the O’Kane house will be completely dismantled, and it is exciting to know that as we proceed, some questions will be answered, and even more created.
Adjacent the feather-edged paneling was the most exciting section yet. A section so exciting as to make the author flap her arms in an improvised, peacock-like dance. Behind the plaster Scott found accordian, or split board lath, hung with wrought nails. Accordian lath is hung using a wide, rough, knotty board. The first edge is nailed to the studs, and then the board is split along the grain and checks are stretched open and nailed, creating voids for the plaster to “key” into. This kind of lath supplanted the use of split, or riven lath around 1800. It was used until the mid-19th century, with the introduction of sawn lath.
Wrought nails were used until the advent of machine-cut nails, invented in 1790. So we were finding a relatively newer lath style with an older nail technology allowing us to date the wall to sometime between 1790 and 1800 (Garvin, p 66). Dating a building without recorded documentation is a fuzzy practice. Often, the invention of a technology allows us to bracket a building’s date into “well, we know it wasn’t built before such-and-such,” and this is an unsatisfactory conclusion. Most technologies were in favor for at least fifty years. We use all these time brackets, and the popularity of certain styles throughout the house, to come up with an approximate date. It is unusual, and thrilling, to uncover a wall that so neatly falls between the advent of one technology and the extinction of another–and that was why I found myself flapping my arms, wildly.
Please peruse the photos below for more information about our process, and stay-tuned for more exciting discoveries.