Craftsmanship doesn’t come easy — or cheap
Original plaster crown moulding can be repaired properly, but it will be expensive
Q Our plumber has had to cut two holes in our dining room ceiling and remove a section of original cast-plaster crown moulding to assess, access and repair the second-floor bathroom plumbing above. We won’t have to pull up any of the near-perfect 1913 hexagonal bathroom floor tile, but I have no idea where to go for replacement moulding. Will we need to have a mould and moulding custom-made, or is this something we could do ourselves? Would it make sense to repair other areas of water damage in the room at the same time?
A The plaster moulding in your dining room wasn’t cast separately and put up in sections. The pictures you sent show that it was run in place, meaning a plasterer pushed in the shape by running a template with the opposite shape against wet plaster.
The moulding and ceiling can be patched in an authentic way to look good as new, but it isn’t cheap. It’s time-consuming and there aren’t many people who still know how to do it.
Reggie Bullard, who has nearly a half-century of experience as a plasterer in Virginia, said he would first assess the situation, then he could answer your question about whether it would make sense to repair other areas of water damage at the same time. Plaster lasts essentially forever if it stays dry, but water can make it crumbly and loose. He would need to figure out whether the other areas are just stained or are disintegrating.
To replicate the missing sections of moulding, he would need to copy the shape, then cut a mating profile in stiff metal. After filing the edge for a perfect fit, he’d outfit the blade with wooden stiffeners and a bottom piece, called a sled, that he could slide against a straight guide screwed to the wall, underneath the existing moulding.
He’d patch the ceiling first, aiming to create a perfectly level surface. He often has to enlarge ceiling holes by another foot or so to get a big enough area for a smooth, level patch.
Although older plaster was typically backed up by thin wooden slats called laths, Bullard often fills in behind with metal laths. Then he spreads on layers of moulding plaster. It stiffens quickly — often in 10 or 15 minutes — so he can do multiple coats.
Bullard estimated that it would cost about US$4,000 to repair each of the holes.
Given the cost of doing the repairs in an authentic way, you might be tempted to do the
work yourself or search for other patching options. There are YouTube videos on how to patch plaster crown. Bullard said the do-it-yourself patches he’s seen look “like you let kids come in and do it with Play-Doh.”
He’s dismissive about patching the moulding with a piece of ready-made moulding, either plastic types such as those made of polystyrene foam or ones cast from glass-fibre-reinforced gypsum plaster.
Still, you might be able to patch in pieces that leave your dining room better looking than now and almost as good as new. Look for someone, such as RWM (rwm-inc.com), that replicates crown moulding and other plaster details using glass-fibre-reinforced gypsum plaster, (which can be shipped to Canada).
You or a contractor would need to cut out a full-width section four or five inches long of each style of moulding, or you could extend the existing saw cuts to get a full-width edge or slot where you could slip in a piece of poster board to trace the profile. From that, RWM would make a custom mould, form the lengths needed and mail them to you. Owner Dan Litson estimated the cost at $1,300 plus shipping if you have a single moulding profile. If you’d need two moulds, add $550. The estimate is based on a guess of four feet of moulding for one hole and two feet for the other; it also includes crating the pieces for shipping.
It’s possible you could have avoided much of the damage if you had called in someone with a restoration mindset to make the initial cuts. When plumbers cut through walls or other surfaces, the holes often aren’t pretty.
You might be tempted to do the work yourself or search for other patching options. ... You might be able to patch in pieces that leave your dining room better looking than now and almost as good as new.