# How to Finish a GROIN Ceiling



## newfie49 (Sep 20, 2010)

any drywall experts or finishers out there that can help?


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## joecaption (Nov 30, 2011)

No clue what a groin ceiling even looks like.
Post a picture of the framing.
I do know what a barrel ceiling looks like.


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## newfie49 (Sep 20, 2010)

a groin ceiling is actually a domed ceiling that all joints meet in the middle, this one has square bottom, 8 x 8, with 16" band then begins to arch to center, 8 sections in all, I've done huge domes that are all round but this is both arched and has 4 defined seams starting at each corner gong to center.
I'm trying to figure out what tape to use, arch tape, flex tape? I have a combination of straight lines and curves??
google groin ceiling and you can see samples.....


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## newfie49 (Sep 20, 2010)

*groin ceiling sample*


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## newfie49 (Sep 20, 2010)

*samples*


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## Total Tool (Dec 4, 2011)

Not an expert but it looks like you would need to score the backside of the drywall kind of like if you were doing the inside of an arch.


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## newfie49 (Sep 20, 2010)

thanks, Its actually not that hard to hang, I'm looking for some tips on mudding/finishing the ceiling......


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## joecaption (Nov 30, 2011)

I'd be temped to use plaster instead of drywall.


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## bjbatlanta (Jul 16, 2008)

You'll basically have to "plaster" it, but it can be done with joint compound. You'll likely have some "stress cracks" in the drywall from bending it. Cut away any paper that comes away from the core of the board and tape those areas. If you have hung radius' before, you probably know it helps to wet the board before trying to bend it into place. Not saturated, just dampened. Sometimes it works just to lay the board on the concrete floor in the basement (if there is one) for acouple of days before you hang it. It will naturally absorb moisture from the concrete. Especially a fresh slab. Looks like the framer did a good job. Be sure to use plenty of glue, it will save headaches later......
Some type of arch bead on the outside radius There are several different types, Strait-Flex is a good product. I'd use mesh on any flat joints. Use setting compound on at least the first coat. I've done barrels, full domes, "eyebrow" dormers, etc. over the years. Can't recall ever doing a groin, but I've seen them and they look good when done properly. Just take your time. Don't try to "pile" the mud on. Several thin coats, sanding in between coats to get your radius smooth. 
It's just something you have be patient with. Best of luck!


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## newfie49 (Sep 20, 2010)

thanks, your info helped


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## bjbatlanta (Jul 16, 2008)

Glad to help. I should have mentioned too that if you have a concrete surface that is not particularly "damp", wet it down with a hose then lay your board on it. It's better to let the rock absorb moisture slowly than to try and get take bucket of water and soak it right before you try to hang it. 
Also, I forgot to mention the inside angles. I have used regular paper tape and let it "crease" over itself on the inside of the radius (depending on the curve).
I have actually cut paper tape by hand (on the inside radius side). Or you can use a Strait-Flex type of product too.


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## newfie49 (Sep 20, 2010)

UPDATE, I used hi-flex 1/4" drywall two layers, glued and screwed and it came out perfect, then taped with level line tape and arch strait flex and it really looked good, homeowner I was told would be extra picky but when he inspected it gave me a thumbs up, he plans on building a $40,000 bar in this same area, I maybe should have charged more, anyway another satisfied customer......:thumbsup:


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## bjbatlanta (Jul 16, 2008)

Glad to hear you were successful! Don't recall having heard of "level line" tape. (Haven't done any radius jobs in a while either.) Can you elaborate or give a source for the product? Always interested researching in new products whether I end up using them or not.....


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## Total Tool (Dec 4, 2011)

newfie49 said:


> UPDATE, I used hi-flex 1/4" drywall two layers, glued and screwed and it came out perfect, then taped with level line tape and arch strait flex and it really looked good, homeowner I was told would be extra picky but when he inspected it gave me a thumbs up, he plans on building a $40,000 bar in this same area, I maybe should have charged more, anyway another satisfied customer......:thumbsup:



Good to know. You got a pic of the finished product?


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