…Emad Andarawis. It was Emad’s insightful and hard-hitting suggestion “I need you to do a post about plaster” that was really the catalyst for this piece. Although I fear this post may not have the level of detail that Emad is looking for (after all – this is the man who has read the entire internet and finds it lacking in answering his questions about plaster) I hope it may prove somewhat helpful. Emad if it does prove helpful, I will take all the credit and if it doesn’t, I blame #3 and #4.
Unbelievable – you don’t check in with the restoration workers for a measly two weeks and they plaster all the walls in the house on you! Maybe not all the walls, just the lower portion of the walls in the North and South Parlors and the Center Hall that were in need of plastering. On the one hand I want to be positive about their work ethic and dedication but on the other hand I wish they had taken a page out of my book and worked SUPER slow so that I would have had the time to snap some pictures of the process. Or make a plastering video – how exciting would that have been? Don’t all respond at once or anything.
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This is obviously not as exciting as watching it live on a video but it's the best I could do. |
Admittedly, I have been preoccupied with back-to-school stuff the past couple of weeks. I’m thinking about starting a campaign to save trees from schools. I have three kids in school this year and they easily get about 9 handouts to take home with them. Every single day. That’s 27 handouts that come into my house on any given day. That’s 135 handouts every week. That’s 540 handouts every month. That’s…that’s a lot of paper. Those poor trees. And what do I do with all of these many, many handouts? If I’m not using them to write down phone messages in illegible handwriting or to mop up yet another spilled cup of milk (whoever said “There’s no use crying over spilt milk” clearly didn’t have four children who spill milk twice a day on average. They’d be crying too if they were on their hands and knees soaking up milk from the stained and dirty fibrous mat formerly known as a carpet), I’m giving them to the garbage men so they have something to throw in to the recycling truck once a week. What I’m not doing is saving them, and I’m usually not even reading them. Wasteful.
But I can’t say there was anything wasteful about the way plaster was made prior to the 20th century. (How’s that for a transition? I’m telling you I could be a TV news anchor - ‘…the blast wiped out the entire town leaving no survivors. [pause, turn the frown upside down and go…] If you’re looking for a blast of fun this weekend, check out the doggy fashion show being held at the Downtown Community Center where you’re sure to see some real barkers strutting their stuff.’)
I found #3 and #4 in the house last Tuesday and by the very nature of the work they were doing, they were unable to escape me. #3 was perched atop a ladder in the South Parlor and #4 was squatting down in the Center Hall with a trowel full of plaster in his hand which he was systematically smoothing over the lath. These boys weren’t going anywhere and they knew it, and they knew that I knew it. I took my time, snapping pictures and then I settled in on the floor with pen and paper in hand and began the interrogation.
#3 begged off talking to me – insisting that #4 was the plaster expert. Maybe he was, or maybe #3 was still recovering from last week when I cornered him for a restoration update. (I wouldn’t have twisted his arm behind his back so hard if he hadn’t tried to run). #4 is no spring chicken so he wasn’t going to get the leg up on me and run out of the place. Having my subjects secured, I had to get them to talk. But how? I couldn’t open with an obvious question like, “What are you doing?” That would make me sound ignorant and I can’t afford to lose my restoration street cred. Instead I tried a much more subtle tack: “Can you explain what you are doing?”
“Plastering.” #4 responded.
Darn, I was back to square one. Time to pull out all of the stops – “Can you explain what you do when you plaster?” The Spanish Inquisition I am not, but effective I am, cause #4 sang like a little birdie.
The first thing he stated was that the lath only existed as a platform against which the plaster is applied. It has no function beyond that – it’s like an artist’s blank canvas, and the plaster is the masterpiece smeared on for display. The plaster alone, once applied and dried, has the strength to hold up the walls.
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#4 is quite the artist. The art world is all afire! |
Typically three coats of plaster are applied to lath to make a wall. The first coat is called the scratch coat. The scratch coat is flexible, it can move with changes in temperature. Plaster is a lime product, which makes it very hard, solid, durable, but it can break easily which is why the scratch coat is applied - to provide the flexibility that the top coats of plaster do not and cannot have. After the scratch coat come two veneer coats. The veneer coats are smoother, the lines left behind by the trowel used to apply the plaster are no longer visible. When the last veneer coat is applied, there may be a need for minimal sanding to smooth out the surface, and perhaps some filling but basically the top veneer coat, once in place, means the plaster wall is ready for the next phase of its makeover – painting or wall-papering.
In Cherry Hill’s case – some extra coats of plaster were needed in order to build the wall out to where it was supposed to be. So Cherry Hill had two scratch coats and two veneer coats of plaster applied to the walls. It takes about 24 hours to let a layer of plaster set. As I write the walls have all been plastered and are prepared for the decorative phase of the restoration work. But why did I mention the non-wasteful nature of plaster prior to the 20th century? I thought I told you that was a transition point. And not such a strong one the more I consider it.
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North Parlor - totally plastered |
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South Parlor - totally plastered |
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Center Hall - totally...um...you probably get the point |
Plaster, as I said earlier, is a lime product and when it dries it is super duper hard. Not only is it functional for use as a wall because of its strength and durability, but it is also an effective means of preventing rats and mice from having the run of the walls in a house. Rodents don’t particularly enjoy eating through plaster precisely because it is hard. They’ll do it in an emergency situation but plaster walls are an effective means of pest prevention. But what was mixed in with plaster to make the scratch coat? (Note – here is where the transition point is explained.) Fibrous materials. Once upon a time, animal hair was an essential ingredient in plaster. Hair from cows, horses or pigs, obtained from slaughterhouses or what have you, were mixed into the plaster to help boost the flexibility of the plaster as the wall moved. That’s what I meant by early plaster production not being wasteful. Get it? Okay, it’s official, my transition was terrible. Nowadays, wood fiber is mixed in with the plaster instead of animal hair, for the scratch coat. More wood – poor trees.
The veneer coat has sand in it. Sand, somehow, lends strength to the veneer coats of plaster which is essential for the top coats of a plaster wall. Sand is always used in the veneer coats of plaster – the Greeks and Romans did it, as do #3 and #4. #4 explained they have to add the sand to the plaster mixture for the veneer coat. Particularly with restoration work, one must be sure to match the size of the grain of sand used in the plaster of the original walls with the grains of sand used in the restored portion of the walls. By taking a piece of original plaster and mashing it up, #3 and #4 can look at the size of the sand and then be sure to add sand of a similar size to the plaster they are mixing for the restoration work.
Who knew getting plastered could be so much fun? Besides college kids, and people at football tailgate parties, the bride’s embarrassing Uncle Steve, grumpy old Mr. Smith at the end of the street, attendees at museum conferences, people who ride mechanical bulls, anyone who has ever sung karaoke….I guess a lot of people knew.