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Extending existing 10 inch plaster crown molding

striker1211's Avatar

Join Date: Nov 2013
Posts: 11

04-04-14, 12:11 AM   #1  
Extending existing 10 inch plaster crown molding

Hello. I recently began replacing wood paneling in our new house with drywall and have been thinking about extending the existing crown molding. This house has been redesigned more times than we can figure out and the molding is missing for some reason in some places, about 30 linear feet worth. We are trying to see if any company makes it out of maybe plastic or foam or wood but are not finding any useful results. If we paid someone to do this who would we call? A carpenter, plaster-er? I feel like we might be able to do it ourselves but would like to quote it out to see if it is worth our time. Thanks

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calvert's Avatar

Join Date: Jan 2014
Posts: 466

04-04-14, 04:28 AM   #2  
You would need the services of a plastering contractor. What you have was more than likely run "in situ" or "in place" by a few guys working in unison...and quickly to get the material in place and profiled for the design. Yours is relatively simple but not for a novice.

A template has to be made to match the design of the cove and then mounted to a jig that will enable you to slide along the wall and profile the unset plaster to produce the pattern. You could also run pieces on a bench and then attach them to the wall/ceiling. Either way requires some understanding of the proper plasters to use .

You might first go to a building supply house that sells plaster and ask for names of a few people that would understand the materials and processes. Perhaps you could obtain the services of a retired plasterer to take on the job.

You could find some similar designs online in cast plaster or other materials but matching the exact radius of your molding is the part that will be the challenge with a manufactured product.

Google "Warehouse Bay Co." In Reading,Pa and look at their line of interior trim made to look like plaster. They also will custom match a profile but you will pay extra for small quantities. I have had them do custom runs for projects where homeowners didn't want to endure the cost or mess of real plaster.

Last edited by calvert; 04-04-14 at 04:58 AM.
tightcoat's Avatar

Join Date: Jul 2003
Posts: 1,676

04-04-14, 06:56 PM   #3  
Plaster is preferred. I have seen coves but not mouldings like yours done with Masonite. a carpenter cut curves to the right radius, put them up then screwed the Masonite to that and used joint mud to ease the transitions. Maybe you could do this with lumber strips top and bottom then flexible Sheetrock or Masonite. i have never run mouldings with a template. there are probably a few old timers who know how or accomplished union apprentices might know how too.

marksr's Avatar
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Join Date: Mar 2005
Posts: 42,796

04-05-14, 03:58 AM   #4  
I've painted a few new construction house where they used a 'decorative plaster company' to come in and add plaster crown and other details to the drywall. What they did was bring in the premolded plaster pieces, install them and then finish off the joints and repair any damage.

retired painter/contractor avid DIYer

calvert's Avatar

Join Date: Jan 2014
Posts: 466

04-05-14, 07:52 AM   #5  
The major issue to consider if you go with cast pieces is that the perimeter of the ceiling HAS to be in a relatively straight plane. Cast moldings don't bend and any high or low spot has to either be chopped or filled to allow for a consistent edge reveal along the wall and ceiling plane.

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