Home > Video Channel > Plaster Cornice Reconstruction

Plaster Cornice Reconstruction

Bob checks out the plaster cornice in the project home. Water damage has ruined a large section of the cornice, and much of the remaining plaster is in need of repair. Bob discusses the various elements and construction process for this style of cornice.
Get Adobe Flash Player to see this content.

Chapters from this episode

Clip Transcript For:

Plaster Cornice Reconstruction

  computer-generated transcript - may not be 100% accurate

" -All four of the main rooms in this house were heavily ornamented. Both the wood work and of course the plaster work and as we said earlier all the straight plaster was torn down but a previous owner left the cornice moldings in place."

" -We are very fortunate. It is a very high style federal and it is probably made up of about six or seven different pieces and we have got all of it this room except for a portion that, I guess, fell off."

" -Right. We have some water damage behind it and it just became delaminated."

" -Yeah. While we are in the process of restoring it and we are going to show how to mend it but first let us look at some of the components here."

" -This a piece that fell off the wall and it shows you a profile and the make up."

" -Uh huh."

" -And you can see the most of the cornice is actually built up brown coat and the actual finished plaster is really about an eight of an inch thick."

" -Right."

" -And the way you achieve all these lines is with a template such as this which would be the original one obviously would have been probably wood and metal but this is just sheet metal that has been cut to fit from the sample and it gets pulled through the wet plaster to create that effect. All we are doing today is putting the brown coat on."

" -That is exactly right."

" -Yeah."

" -But these are the pieces that would make up the applied elements after this section is run then the [unk] sleeves were mounted."

" -Okay. The wall would have been coming from here and you would have an [unk] sleeve every couple of inches or so."

" -Right and then the triglyphs would have been mounted like that on a ledger called triglyphs."

" -This is all Greek."

" -That is right and then the smaller [unk] sleeves were mounted up above."

" -Exactly and then along the lower portion."

" -Is made up of several cast elements that match like this."

" -Can these actually have like a cornucopia with fruit and I see what probably are [unk]."

" -She is a [unk]. Yeah."

" -Let us go up there and get a closer look at the rough work."

" -We are off to scratching the plaster now. This is 1810 we are looking at over here."

" -That is right."

" -This is the original plaster work."

" -Yeah and you can see a missing one here and of course the pieces that we were just talking about fit right into place. The [unk] pieces but it is fascinating to get this close up and to see some of the color that is still there."

" -You see a lot of light blue in here which was the color obviously at one time."

" -Uhum."

" -And we have a picture mold here."

" -Yes."

" -That captured some early paint, some greens and blues."

" -What has happened to all this? It does not have the crispness that I would expect."

" -Unfortunately, the previous owner that tore off the plaster work applied chemical strippers to remove the paint."

" -That is a big mistake."

" -Right. We never apply chemicals to plaster because it is porous and once the chemicals get in, it is hard to get out and it can also deteriorate the [unk] and totally destroy it."

" -Right."

" -But is fascinating to be right up here next to this work. Look at the thickness up here of the brown coat. Look at the few remaining hand split [unk] and look down here at this detail, how they framed this."

" -Yeah. That is a more [unk] and instead of hanging with round [unk], they have actually driven a wedge."

" -Yeah. The header goes right through the jacks and then they had a wedge to tighten it up. You can probably take this house apart without having to use a crowbar or anything."

" -You could."

" -Here is an interesting thing we do. This is a plaster washer and this whole section was loose so we have come in and drill holes and then fastened it with a plaster washer and screws and that is a mechanical reattachment back to the stud."

" -And you want to preserve as much of the original plaster even if it is bits and pieces like this."

" -That is right. You do not want lose it."

" -This is a diamond mesh, right?"

" -Yeah."

" -Yeah and it has just been nailed up over a 15-pound felt and I can see you had to have a couple of 2 x 4's to help create the profile of the cove up here."

" -Yeah exactly."

" -Right. Now what is it you are using? What is the [unk]?"

" -This is gypsum plaster, Gypsolite. It has vermiculite added to it. It is thick and light weight gypsum plaster. "

" -Sure."

" -And we have to apply several coats because it will shrink and crack. We will apply it too heavily."

" -Okay. So right now you are putting on the first coat and is there?"

" -Yeah, the first coat."

" -Now this is a hock down in the south."

" -Yeah."

" -It is hod up in New England and you basically just have to develop a technique but I have a great technique for spilling it on my shoes that I have to show you sometime."

" -I have done that before."

" -Yeah indeed but it is fun. It is one of my favorite trades. Now how do you deal with the build up that you got to do up here?"

" -Well, yeah, as you can see we curved it to fit the curvature of the ceiling itself and we will just apply 2 more layers, one more layer and then the white coat layer then the finishing coat."

" -Go for it Ralph Let us watch your technique for a sec."

" -You cover the wire completely and then you come back and add more."

" -So the mix is made stiff enough, enough that you can ah."

" -Yeah, it is just powder form which you say I order."

" -Yeah but you do not ask so much, you got to mix it."

" -Oh no it is definitely [unk]."

" -Exactly."

" -And also carried away of itself."

 [-]


More Videos »Related Videos

Painting Plaster
Painting Plaster

If you're repainting older plaster, take the extra prep time to make the effort worthwhile. Use patching plaster to smooth cracks and imperfections in the plaster before you paint. If there's an angle that's in bad shape, use corner bead to form a crisp new profile under your new paint.

Plaster Reproductions
Plaster Reproductions

The lost art of Victorian plaster details is making a comeback - in a new form. Modern manufacturers are finding ways to reproduce cornice moldings, friezes, corbels, brackets, rosettes, and ceiling medallions, using lightweight polymers. Less prone to damage than plaster, polymer details are flexible, paintable, easy to ship, and they come in a wide variety of shapes and sizes.

Marmorino Plaster
Marmorino Plaster

For a rich wall treatment that's truly unique, find out more about marmorino plaster. Developed in 16th-century venice as a lightweight alternative to marble, this mix of marble dust and plaster with custom pigments requires two coats, a waxy finish, and lots of elbow grease, but the results can be spectacular.

Patching with Plaster
Patching with Plaster

Chris Borovka from US Gypsum joins Bob explain about patching with plaster. The first job entails patching over an existing door opening. They've put some Imperial Gypsum base up to the existing door frame and patched the existing hole with diamond veneer base coat. Next they put pressure sensitive fiber tape, P-Tape, over it and bonded the entire existing surface. The use USG Plaster Bonder Pink as a bonding agent - it rewettens and re-emulsifies - and put the base coat of plaster over that. Where the wall meets the ceiling, they apply pressure-sensitive tape to the existing surface and butt it in while applying the first coat of base coat. The first coat provides a nice even scratch coat. The second coat should be applied while the first coat is still fully wet and serves to take out some the bad dips and dives and the trowel marks from the first coat leaving a nice smooth finish. The next day you they'll put the finish coat over it. Where the insulators drilled holes into the original walls, the plasters put the Plaster Bonder Pink around the inside of the hole and fill it in with the base coat. They've meshed over the top of that for extra security and then bonded over the whole surface. On the blue board, it's a different type of installation. Shreve applies one-coat over the joints to reinforce them and fill in the undulation that's left from the two end tapes from the butt joints. That sets up for about an hour and then it's ready for finish coat.

Related Products & Services Showrooms

Columns, Pillars, Pilasters & Balustrades
Columns, Pillars, Pilasters & Balustrades

Chadsworth offers a complete line of columns, pillars, pilasters, and posts for both interior and exterior use, with plain or fluted shafts in Wood-all species of lumber (stain- and paint-grade), their award-winning PolyStone', Composite, Fiberglass (molded and spun-cast), and PVC. All sizes and

More Content »More Content

Choosing and Using a Pressure Washer
Choosing and Using a Pressure Washer

…a day. Cleaning power: A pressure washer is the perfect tool for removing the dirt…
…Seal. Cleaning power: A pressure washer is the perfect tool for removing the dirt…
…There are four basic elements to pressure washer performance: pressure, flow rate, temperature…

Rebuilding a Wall with Three-Coat Plaster
Rebuilding a Wall with Three-Coat Plaster

A traditional three-coat plaster job was used in the Manhattan Brownstone…
…finish or white coat that blends the new plaster wall into the profile of the cornice…
…where new support is needed for the plaster application. It has many "keys…

How To Replace Old Washer Hoses
How To Replace Old Washer Hoses

… Step 4: Disconnect the hose at the washer inlet Diconnect the the cold-water…
…the new stainless-steel hose to the washer at the cold-water inlet. Step 6…
…tighten fittings to stop leaks. Move washer back into place. Tighten the fittings…

Blue Board and Veneer Plaster
Blue Board and Veneer Plaster

…characteristic hue comes from a special plaster-friendly paper applied over its gypsum…
…commonly known as drywall pushed traditional plaster out of the new-home market. Everyone…
…to a skim coat of specially formulated plaster. When finishing blue board, instead…

Browse Topics

Click on a letter to browse content by topic alphabetically.



About  | FAQ  | Contact  | Sitemap  | Privacy Policy  | Terms of Use  | Help

© BobVila.com 2009