*
Many houses in North Carolina that were built in the 40s and 50s have interior arches from the living room to dining room or kitchen. I don’t believe I’ve ever been in one of these homes where the plaster on the arches were not cracking terribly. Is this a problem from support below or above? Wasn’t sure if the best way to remedy the problem was to put a footing below with a post up to the joists or girder above, or if these things were built without a proper header, and the better solution would be to tear out the arch, put in a better header above, then put in a new archway out of plywood covered with drywall.
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Skim-coating with joint compound covers texture, renews old drywall and plaster, and leaves smooth surfaces ready to paint.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
*
DML:
Well, guess what! I'm currently building a house in NC with interior arches - hope they don't crack!
FYI - if you replace the bad arch with 2x4 framing and drywall (total wall thickness of 4.5"), the drywall guys around here use a flexable plastic "channel" corner bead to wrap the arch. Makes it quick and easy.
*Interesting -- our VA 1940 house had an arched passageway as you describe, so does the sister house next door. No cracks despite a fair amount of curvature in the floor anf ceiling. It has probably been repaired at some point.Where are the cracks? Is the wall load bearing or does it follow a doubled joist span (ours did)? is the floor sagging? Etc. Plaster cracks like these reflect movement in the frame of the house.I say we "had" an arch because I removed the wall, keeping one half of the arch and imitating it on the other end. We'll see how mine does. I can tell you it is bloody strong, partly because I had to fiddle a bit to get it right. It has a plywood backing and it laid on expanded metal lath with a wood-fiber brown coat. i used regular metal corner bead snipped every inch or so, 'cause that's how they did the original arch. In fact, they just smeared finish plaster over the bent corner bead, so the arch surface was only 1/8 - 1/4" thick!
*I redently rebuilt a house my grandfather had built in the late 40's. It had three of those arches none were cracked. they all had headers. The house had setteled a little but the arches were fine. Before you build a pier check the floor for level and straight. If it is good check the ceiling above. If it is good dont rule out a moisture problem.
*Thanks for your responses, y'all! Andrew, the cracks are at the bottom of the curved arch. Basically where the stud meets the arch. Rick -- thanks for the advice on checking the floor and ceiling for level. There is definitely some deflection in the girders under the house, but none of the walls or ceilings are showing nearly the cracking as the darn arches. Matt, good luck with your North Carolina home -- it's a great state.
*DML:Just as an FYI, the point in the arch where the radius meets the jack stud is called the "spring line".
*The spring line should be an especially weak point, because of the abrupt change in direction. Interesting.
*In my experience, cracks mid-span are usually caused by an undersized header overhead. Cracks near the spring line are more commonly caused by settling below...floor joist/beam deflection or shrinkage, etc. I see the latter more often when one side of the arch sits on or near the main beam in the house, the other sits out in the room on the floor joists. (arch runs parallel to the floor joists)In new construction I've seen drywallers slather on too-thick coats of fast-drying compound near the springline, trying to make a fair curve on a poorly framed arch. These thick coats shrink and crack near the spring line. The cracks may be immediate of not show up for a month or two. Callback time. The better drywallers will use Durabond to build the curve, then a fast-drying mud for the final coat. The great drywallers make sure the poorly framed arch is repaired prior mudding.
*Durabond's not fast-drying? I sure felt in a hurry. having that *&(^% cement setting up on everything (compared to mud).
*Just a suggestion - I just started using a product called "Magic Corner" for off-angles like chamfered ceilings and arches. It is basically two pieces of flat vinyl connected by a thin piece of flexible PVC (that what they say it is,anyway). It conforms to any inside angle and the flexible piece in the center prevents cracking at the springline. It also has the fringe benefit of making it much easier to get nice straight lines on long joints in angled ceilings. Much better than endless coats of joint compound and one of those rubber spackling knives. The best way to put it up is to snap two lines and use spray adhesive to set it(best done with two people). Anyway, I think it's a lot quicker and easier and a year later, no cracks even in 20' spans. Please forgive the horribly cheesy drawing. I have Autocad but it seemed like overkill.