I built an addition two years ago. Room has a bastard hip roof. We had the drywall crack at the hip about six months after we finished. I sent the finisher back over to re-work the area, new tape and mud. about six months later, the crack is back, but not as bad. NAHB quality standards say it is not my problem this time. I am curious how others handle similiar problems, espcially drywall callbacks?
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do you mean the room has a hipped cieling? With drywall placed directly on the bottom of roof rafters?
Every load issue in that roof and every dimensional change in the lumber from temp or humidity is telegraphing through and stressing the drywall joint there.
you could have undersized the framing too, but most likely is that it is almost impossible to vent a hipped cathedral cieling adequately.
Without more details, I am making assumptions and it sounds like a poorly detailed design thing
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Yes, it is a hipped roof with the drywall attached directly to the framing. The roof was designed by a architect, and was vented through the soffit and with a roof vent.
It is poorly vented then. To vent a space like that, air has to flow in at soffit and out at the top. At each rafter bay. Hips are harder to deal with because each bay terminates at the hip rafter. So with no detailing to mopve that air, it gets trapped. Temperatures and humidity can experience wilder swings and the joints can move, transmitting that movement to the SR. I would deal with that in original construction with breather notching in rafters and using strapping to ispolate the SR from the framing.
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What the heck is a bastard hip roof? Never heard the term.
Just because the thing was designed by an architect does not mean it was well designed!
What sort of material is the roof frame made of?
+++++++++++++++++++++++++++++++++++++
"Doubt is not a pleasant condition, but certainty is absurd." Voltaire
Irregular pitched hip roof. Where the roofs intersect at different pitches. 8/12-12/12 is an example.What's wrong with me? I could ask you the exact same thing.
Are you sure you aren't looking for the word "mansard" roof?+++++++++++++++++++++++++++++++++++++"Doubt is not a pleasant condition, but certainty is absurd." Voltaire
Here is a picture of one from Joe F's.http://www.josephfusco.org/Articles/Roof_Cutting/raftercutting.htm#Understanding%20Bastard%20Hips%20and%20Valleys
I am sure that they are called bastard or irregular hips.
Say the front and back of a house are a 10/12 pitch and the sides are 12/12 pitch. Thats considered a bastard roof.What's wrong with me? I could ask you the exact same thing.
Thanks. I get it now. I wasn't correctly picturing what was being described.+++++++++++++++++++++++++++++++++++++"Doubt is not a pleasant condition, but certainty is absurd." Voltaire
No - a bastard hip is a hip roof with tow different pitches on either side of the hip rafter.A mansard may or may not be hipped and simply changes pitch part way between eave and ridge, similarly to a gambrel
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You need to use the proper tool to make that work. It is by a company called StraitFlex. The product is X-crack. It is a metal movement absorbing material that is attached to the framing. Then the drywall is attached to that and not the framing. Then the Straitflex Standard is used to tape the inside corner or a No-Coat product. It may be possible to get a good result with just the NO-Coat or STraight flex Standard, but I have had some corners that have enough seasonal movement to even overcome those products alone.
I was thinking about No-coat corners but wasn't sure and thanks for word on the other product.
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Recurring cracks aren't usually caused by the taping job, in my experience. They're usually caused by shrinkage or movement in the framing members.
"...never charged nothing for his preaching, and it was worth it, too" - Mark Twain
Every couple of months, usually in response to a project photo posted by Mike Smith, someone asks "Why do you strap the ceiling?". Thanks for providing a fine example of the primary reason.
IMHO, 1x3 strapping is the cheapest insurance available to any builder or remodeler.
Just my $0.02
Jim
The awful thing is that beauty is mysterious as well as terrible. God and the devil are fighting there, and the battlefield is the heart of man.
- Fyodor Dostoyevski
Sometimes when a definate angle cant be achieved for a straight plane line from top to bottom of the angle like in this case a "curved" inside angle can be set with mud alone hiding the fact or masking it . That often happens in conditons like a 22 1/2 degree angle for example or less . There simply isnt enough of a change to run a knife to a decent angle to provide a staight line. If the lumber takes a dip or a hump or other wise is not straight a drywaller has to follow it so then a taper has to finish it too. One of the big no no s is not to complian to the builder which might have also been the framer . So "fix it " is the alternative . You get no where by complaining about a carps work when you will be talking to one .
So the alternative is to run the corner with a rubber knife that rounds the process . The knife is flexible so it fits what ever angle is there . Also works with round rooms.
Anyway when mud is built up on tape excessively it normally cracks the mud itself .
I doubt you will find the tape cracked . If it is you have some serious problems going on.
I run a glazer head on automatic equipment on 90 degree corners . In corners that are needing filled the glazer head does the same thing as I discussed. It is flexable or it woudnt work. So the glazer finds the angle and runs on the out side . The middle meets where it gets tight and makes an inside corner whether there is one there or not so a corner may be built from mud. In those cases of building a corner with mud it will crack the surface mud.
On still yet another example if the walls are coated with heavy wall texture they will also crack in the corners on the surface .
The quick fix is to run a bead of flexable caulking such as clear 30 year caulking which is paintable and will keep the corner flexable. Clear seems to have the best flexability .
Tim
"...about six months later, the crack is back, but not as bad. NAHB quality standards say it is not my problem this time."
Your attitude is consistent with your build quality. Can you say "hack"?
DG/Builder
easy there, she paid to fix it once and is still searching for further recommendations.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!