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I have a 4 year old house with a bay window in the kitchen. The 3 walls that make up the bay come together at 45 degree angles. My problem is that the tape joint at these 45’s are constantly cracking. I’ve had dry wall contractors try to repair it, but it doesn’t last. Recently, a roof leak has forced me to replace some of the dry wall in the bay, and I thought this would be a good time to entirely replace both 45’s and try to get them right. My question is, what’s the best method for getting a stable 45 inside joint? I’ve seen joint tapes advertised in Fine Home building that have metal incorporated. What about fiberglass mesh? The regular paper tape didn’t work the last time, so I want to specify to the subcontractor what material to use. Any insight would be greatly appreciated. Thanks.
Eric “Cracked & Frustrated” Mueller
Replies
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For about three years I've been using a product called Straight Flex in a lot of inside corners and all off angle corners. Its vinyl, but goes on like paper tape. Not to be confused with solid vinyl corner I've been hearing about. The main thing about it is when you finish, you don't have to leave mud over it in the corner- when you sand it doesn't scuff up and the edges feather easily. I still think its a miracle and none has failed me. Phone around to the drywall suppliers, somebody will have it but not all of them.
*Eric - does your foundation jog out to support that bay, or does it cantaliever? Is it possible your framing is flexing enough to crack the drywall joints? Why did the roof leak? Was it "worked" loose by flexing framing too?
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Yes, the foundation supports the bay. I suspect that wood shrinkage is the culprit. As for the leak, I tried to stick to an authentic construction of the bay roof, with a lead pan that slopes into a trough. Unfortnately, one of the joints in the pan failed. The pan is coming out and a rubber membrane is going underneath. This was my bad. I should have speced that in the first place.
*As a drywall contractor I was frustrated by 45 degree corners for many years until I discovered a product called ultaflex no-coat. I think it is the same stuff advertised in FHB as "structural" corners. (whatever that means) The wideness of it produces straight corners without the waves and doglegs you get with paper tape or the metalbacked flex tape. The cracking is weird though, and may indicate movement your wall as another respondent has suggetsed.
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Many times the framing corners don't get nailed off to each other. Proper fastening of the pcs/parts will go a long way in to stopping the cracking. And not just the outside of the 45's. If it's impossible to get to the inside corners now, try those simpson angled plates (adjustible) a few times up the corner. You can mortice them in if you feel the board will show the bump. Best of luck.
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Eric,
Trim-Tex makes a PVC "expansion" joint with a soft center that flexes and bends as the structure expands and contracts. It is called magic-corner and is used alot for off angled walls and cathedral ceilings. I handled 10 footers but they also came in 8 and 9's. Your lumberyard or drywall supplier may have them in stock. Scott
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I have a 4 year old house with a bay window in the kitchen. The 3 walls that make up the bay come together at 45 degree angles. My problem is that the tape joint at these 45's are constantly cracking. I've had dry wall contractors try to repair it, but it doesn't last. Recently, a roof leak has forced me to replace some of the dry wall in the bay, and I thought this would be a good time to entirely replace both 45's and try to get them right. My question is, what's the best method for getting a stable 45 inside joint? I've seen joint tapes advertised in Fine Home building that have metal incorporated. What about fiberglass mesh? The regular paper tape didn't work the last time, so I want to specify to the subcontractor what material to use. Any insight would be greatly appreciated. Thanks.
Eric "Cracked & Frustrated" Mueller