The Ashlar Treatment, or on How to Make Stucco Look Like Ashlar Stone Blocks

Preservation specialists are now working on the final details of the Cloverfields restoration, including finishes and paint. And they keep making some very interesting discoveries. A few months ago, the painters were working on the 1769 paint layer, when they noticed that the stucco had been scored to make it look like ashlar.

In the video above, architectural historian Willie Graham explains the historic relevance of the ashlar treatment:

This is very exciting, very interesting. It is more interesting to see what the painters have uncovered than it would be for us to freshen up the paint and paint over, and sort of mask this original finish. The fact that we are down to the 1769-paint layer here; that they were able to get us down to that is just pretty extraordinary.

Photo of the stair head on the second floor of cloverfields. Photo provided by willie graham, december 2020.

Photo of the ashlar patern in the stucco at cloverfields. Photo provided by willie graham, december 2020.

I think part of what they are doing is… They’re making it look like stone blocks; “ashlar” is what they would call it. That is a particularly relevant treatment for entries and passages. They are trying to bring the indoors out, and outdoors in kind of thing, and these ashlar blocks are sort of one way to do that.

The stone imitation functions as an indoor-outdoor connection for transitional spaces. Graham continues:

The yellow color on it is also a very common treatment for these spaces, so this is probably the most literal incarnation of the ashlar treatment, where you actually score it to make it look like stone blocks.

Photo shoing the faux stone coursing in the center hall at cloverfields. Photo provided by Willie Graham, December 2020.

In the Chesapeake Bay, it is very unusual to find walls that were scored to imitate stones. Graham knows of only one other historic house where the same technique was used: a house in Anne Arundel County called “Larkin’s Hill.” Graham says:

The only other one of these that I know of in the region is a house in southern Anne Arundel County that's called “Larkets Hills” and it has a lot of this scoring kind of peeking through the walls. It's been patched and skimmed in places, but you can still see the treatment on the arches and some of the scoring of the lines to create the stone. And we have a period account where the daughter of the builder talks about the treatment and how it was made, and it seems to relate a lot to this.

But these are the only two I know of in the region where it literally is made to look like stone.

It's not the only way it's done. At the Brice House in Annapolis in the late 1760s they put a slightly textured plaster in the entry and the stair passages all the way up to the attic, and then they painted it with a yellow distemper paint but very similar to this yellow lime wash that we used here, as a way to suggest that it's stoned without going through the trouble of actually scoring it to make it look like stone.

photograph of the Brice House, Annapolis, Maryland. Photo provided by Willie Graham, 2016.

We find sections of Cloverfields, of Larket Hills, and of the Brice House where the eighteenth-century walls are subjected to different treatments to make them look like stone. At Cloverfields and at Larket Hills they actually went through the effort of scoring the stucco; at the Brice House, they simply used lightly textured plaster.

Preservation specialist Chris Mills agrees with Graham regarding the historic relevance of the ashlar treatment:

This is a very deliberate large element. And how interesting it is that the longer you are with the building and the more it opens up the more you can discover and see, and to see this whole scale of treatment was a great find. William [Graham] had only sent me pictures of it, I had no idea the scale of it; I thought it was a small piece. We did see a little bit that is exposed downstairs but it looked like distemper and we had no idea what it was, and it looked flat so I said: “Oh! It's either a whitewash or a distemper on there,” but it is this treatment that is fabulous.

Graham then enumerates the reasons why the plaster treatment is distinct for a house of the late eighteenth century: It is exceptionally wide, the material used was of the highest quality, and the workmanship was exceptional. Graham says:

What is really interesting about the plaster in the house from this period, the 1769 period, is very distinct.

First of all, it's put on really wide laid bits; it's split out on riven oak lath that’s really wide. It's a couple of inches wide which for this region particularly is unusual.

And then they did a very competent job when they applied it. They used good materials, they used a higher percentage of lime that you would find in a lot of houses. Although they are not using long floats to get real smooth surfaces, they have carefully worked the surfaces to get the nice and flat flush.

The finish coat is really hard and durable; that’s true for the plaster everywhere that was done in 1769. Here, the top plaster layer that creates the stucco look is treated differently; it's also hard and durable and really beautifully put on, but it has this gray cast to it, and that to me relates it potentially to the house in the southern Anne Arundel County, Larkin’s Hill Farm.

in the image is a portion of the original, 1753 exposed stucco work at Larkin’s Hill Farm, Maryland. Photo provided by Willie Grahm, 2016.

But inside, eventually, you go from this to wallpaper, and certainly, by the nineteenth century they are printing wallpaper in ashlar patterns to look like stonework, and it's common up through the middle of the nineteenth century. They eventually get more stylized and it evolves into other stuff after the middle of the century. But I think there is a tradition from about 1760 to 1850 of treating these passages in that manner.

One of the most rewarding aspects of working in a three-centuries-old house like Cloverfields is to find unexpected features or techniques. In the past we discussed, for example, how the archaeologists of Applied Archaeology and History Associates found one of the few surviving wooden eighteenth-century ice houses at the Cloverfields site. The archaeologists also found evidence of a front porch—the first porch of its kind in the Chesapeake Bay. This time, it was the painters who made an exciting discovery. They showed us that in 1769 the ashlar treatment was used to make plaster look like stone blocks.

Like the porch, the ashlar treatment creates an indoor-outdoor connection to highlight the transitional nature of entries and other sections of the house. Cloverfields was one of the first houses of the region to attempt to bring the outdoors indoors by imitating stone, an idea that was popular up to the middle of the nineteenth century. Once more, Cloverfields helps us fill in the gaps of the architectural history of the Chesapeake Bay.

Update on the Gardens

Over the past few months, McHale Landscape has been working to recreate the Cloverfields falling gardens. Kimmel Studio Architects created designs for the gardens based on ground-penetrating radar and archaeology to know where the parterre gardens were located. The falls (terrace hills) were still visible. We will provide more updates on the gardens as they develop.