I read the timely article on framing curved walls in the July issue, as I’m preparing to start building a house with 4 semi circular bump outs in it. I got the framing issues but does anyone have some nifty techniques or advice about installing the flat windows (clad) in the curved wall surfaces and trimming them ; both inside and out. Exterior finish will be stucco; interior finish will be sheetrock.
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Frankie:
I am not a framer but as a finish carpentry contractor we see a lot of curved walls these days. One type that I have seen is very thick and built with an outer 2x4 wall and an inner 2x4 wall. The window or door is a flat area between the two. It is recessed in from both the outside and inside "layers". The inner and outer walls are spaced apart a little to allow for the window area and for the outer stucco and inner drywall to return to the flat portion that lies between the two. We regularly see a certain model with enough lumber in its turret entry to build a small apartment. The studs are tightly spaced to get achieve a smooth curve. A lot of labor and material appears to go into this type.
Another method we see for doors is to simply flatten the part of the curve where the door or window lies. Usually the area above the door header continues the curve and overhangs the door. In other words the door viewed from the outside appears recessed and from the inside is on a flat section.
An aproximation of a curve we have see lately is four sides of a 16 sided polygon that creates a quarter of a turn. All the walls are straight so windows and doors are easy but it has the over all look a curve. The particular one that I am thinking of is a neat design because the quarter round pops out for a kitchen nook on the inside corner of an "L" shaped portion of the floor plan.
I'm sure there are other ways... and I hope most of this made sence.
Ross
Thanks Ross,
I too was thinking the windows would have to be recessed into the outer wall area . hence the stucco. Frankie
Couldn't you kerf the frames and heat up the glass and bend the window to fit the walls?.
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Just kidding
:^D
Mr TDo not try this at home!
I am a trained professional!
Mr. Toot...... no need for that, just soak them in water.no turn left unstoned
I've been messing around with curves for many years and I discovered that metal studs & strategically placed sheet metal can make the job not only easier & cheaper than wood.
Besides, just think of the concrete $$ you will save by not having a 'small apartment' foundation in 50 square feet of your house.....!
Another thing I have developed is a technique for sheet-rocking the inside & outside of curves.
I use 2, (or even 3 sometimes), layers of 1/4" rock. I scribe it 30-40% through with a utility knife & straight edge on the appropriate side: the outer on convex shapes, the back for concave shapes.
On tight convex shapes, I may also use a grout removal tool on the back to 'take away' some of the sheetrock. I try to keep the scribings parallel around 1/4", but no farther apart than 3/8".
Depending on the 'tightness' of the curve, I decide how to cut the sheetrock. The tighter the curve, the narrower they must be. (I did a 12-14" half column a few years ago and ended up cutting the rock into 9" strips, max.)
These strips are fitted from R to L across the length of the curve's radius. SO, you cut them as long as you can handle after they are wet. The only thing to do is experiment. The more coordinated pairs of arms you have available, the better. After a bit you can handle a 4 footer....
Also, you should cut the rock strips with the 4 foot side of the rock as the 'grain' of the rock is more conducive to bending in that direction.
I then cut a nice hard 2 X 4 w/ two chamfers. One on each of the 4" sides, along the same 2" edge. (Think of sharpening a 1 X 2 into a stake.) The length is determined by how wide you cut the sheetrock strips into. It needs to be 2-3 times the width. I then fasten this onto a couple of sturdy sawhorses, with the 'sharp' edge up.
Now, fill a bathtub with nice hot bath water. Soak the rock in it after it is cut and scored. The time depends on the 'freshness' of the rock and the temp of the water. Watch the air bubbles coming off it as that is also a good indicator.
When fully wetted, place the rock along the 'knife' edge of your 2 X 4 and work along the length of each scribe, 'breaking' the wet rock and forming it into a curve. This is hard to tell you how to do, just try it....
Let it dry a few minutes. ......(I usually go threw a bunch of old towels since I like to dry it off. The idea is to soften the rock w/o killing the adhesives.) While you get another piece going.
(I tend to cut & score, then wet, form, hang in two major stages.)
Now you can attach the rock to the curve. Start at the top w/ a 'half-width' strip working across the length of the curve and then down. Stagger your butt joints, if you have to have any, and use 'full-width' strips on the 2nd row on to the bottom.
As you begin with the final layer, start at the top & overlap, vertically, the 'half-width' strip with a full width strip. Continue down the wall until you have staggered all of the joints and rocked the wall.
On the first layer, I try to keep the 4 foot gaps from being under the second layer's 4 foot gaps. Any method of staggering you use to do that, is fine.
Screw the rock sparcely on the first, (and/or middle) layer so the final layer's screws won't hit underlying screws. The 2nd or 3rd layer holds down the under-layers, anyway.
(I want to digress a bit on the 2 or 3 layer comment: I use three layers if the curve is fighting me. It's easier to take this bail out option if it is a concave curve than a convex. Remember, you go up to 3/4" thick.
If I need to, on a convex curve, then I just cover the rest of the wall with 1/4" rock.
As far as the 'fighting', it just seems to get easier to hang this curved, grooved, wet stuff the more layers you do! I don't hesitate to pull off a strip & cut one off of another sheet of rock.
SOMETIMES, it's the rock and not me. Everytime I do these, I try to start slow & "get the hang of it" again.
The other reason to use 3 layers is when you have a less-curved wall. Your studs end up farther apart and the third layer gives some great strength.
If this is a concave curve, finishing out the 'ends' of the curve is easy w/o adding another layer of 1/4". Just make sure you hang the flat wall rock first & then make each layer extend a bit farther out onto the flat wall.
****Remember, the 3rd layer and adding a 1/4" to the flat wall is a bail-out, plane's-on-fire, nothing is working situation.)
Ok, one last thing on hanging - hang it while the rock is still soft from the water. It allows you to more 'gently' place the screws, they sink very easy into the wet rock. Also, it gives you a chance to use a block of wood & hammer to GENTLY 'crush' the rock into a nice smooth curve.
One last trick -
When you have the rock hung and your're ready to mud, use some vinyl/plastic window screen material. I start at the top, smear some mud on, in a 1/8" coat. Do as much as you can handle. Start small and, after a while, you'll find that you can do bigger and bigger areas at a time. Overlay any joints in the screen seam by an inch or so.
After the screen is set. in the area you plan on working that day, smooth out the mud as well as you can. But don't get too picky, it's real easy to catch the corner of your trowel or blade in the screen, snag it and pull it up. Work confidently, but smoothly....keep your eyes on what you're doing.
After the screen is set, keep adding coats of mud until you have an incredible looking curve. I coat with, at minimum, two coats of tape-setting mud before I move to topping mud.
I always go to topping mud, though, usually three coats. Since the topping mud is a different color, it helps you keep track during the sanding, as well as making the sanding easier.
I also will wet-sand between coats of mud, where necessary, and ALWAYS scrap the ridges, etc in the hardened mud to get it smooth before the next coat of mud.
I know this seems like a butt load of work, but I can tell you that people are blown away by the curves in my house & others and my customers have ALWAYS been smiling wide when I'm done. It really goes quicker than it seems and it is one well-built, great looking curve when you are done.
I ran into one or two minor cracking problems in the early days, but I think that was do to thinning the mud a bit too much. (I used to do that.....I was taught mudding that way. Anymore, to me, thinning mud is a personal-thing: keep it to a consistency that is easiest for YOU to use.....)
Make sure you also get good screen cover at the 'ends' of the curve where the flat meets the curve. This will keep the joint from cracking.
Good luck with your curving adventures, it's the great part of being a carpenter, exploring the artistic boundaries.
The downstairs bathroom in my house has no vertical 90 degree corners, only curves. Also, there is an El shaped open soffet about 9' by 5' over the sink/counter-top. Everything is curved, cabinet end, all of it.....except the shower door! You should see the looks it gets....
GeoD
The 1/4 inch sheet rock is available as High Flex... this product has additional fiber in the gyp.... this will allow you to roll the rock to a much tighter radius. You may find that the direction the rock is rolled will determine the quality of the finished product, by this I mean ,roll from the butt side,48 in. is for lesser a radius, and a roll from the rip side , the long side, for much tighter radius. On occation thicker rock1/2 or 5/8 rock can be rolled with ease by wetting the paper on both sides lightly, and waiting for a uniform color to appear in the paper then start at on end and completely screw off each stud as you progress around the rad. Generally 5/8 rock will roll to 12 dia, 1/2 in roch will roll to 9 ft dia. and standard 1/4 in will roll to a 4ft dia... high flex will roll as tight as 12 in dia, if it is done right.... Mark.... DW Supr't Matrix DW/ Dallas TX.
is this from an issue of fine home building ??
This is completely off the subject but here goes. Your comment brings back a question I've had for some time now, why don't some of these window companies make a curved thermo windows like they use to make around the 1920's and 1930's. I know it would probably cost a ton but I can't believe there isn't a market for it in the appropriate spot. I know the older windows were only single pane jobs but they do look nice and if you install a flat glass window in it's place, it just doesn't have the same quality look to it.
Anyone out there in the window biz to answer this ?
I'll bet Frankie would buy one or two without hesitation and I'm sure there are more curved wall fanatics around.
I believe Anderson can special order that window
Marvin will do that $$$!
curved wall....14" rock is ok,
plaster better. Do anything you want with plaster.
It's all out there....for a price