Background:
A few years ago, we took out the walls in our house that stood between the living room, dining room, and kitchen. We did this based on a plan drawn up by an architect who told us that we wouldn’t have any trouble with this because we had a truss roof. The first winter, we had a couple of cracks that showed up in the ceiling drywall perpendicular to the trusses. Each winter, the cracks are a little worse than the previous year. Each summer, the ceiling looks better but not as good as the previous summer. In addition, in one corner, the wall and ceiling pull away from each other in the winter, to the point where you can see a gap between the two. (In case it makes a difference, the trusses are 24″ apart with 5/8″ drywall on the ceiling.)
I am currently redoing our master bedroom and I’m interviewing people to do the drywall. In addition to talking to them about the bedroom, I’ve been asking what it would take to fix the living room ceiling and whether it’s possible to fix it “permanently”. I recently had someone who told me the way to fix a problem like this is to redo the seams and the corner and make sure that the drywall is screwed down tight around the edges.
Questions:
1. I had the impression that screwing drywall down tightly around the edges of the wall and ceiling was exactly the opposite of what should be done. I thought that you shouldn’t put screws closer than 3 or 4 from the edge so that there is some give in the corners when the house inevitably moves. Is this true?
2. I’ve been trying to find someone who knows what they’re doing in drywall, and not just someone who gives me the cheapest price. I’m having a hard time finding someone in my area who specializes in drywall, instead of a handyman who also does drywall. I want my best chance of getting a job that looks good even after the seasons have changed a few times. Can anyone give me any suggestions for finding someone, or about questions I might ask to figure out if someone knows what they’re doing in this area?
Replies
no amount of drywall work is going to correct a structural deficiency... and a structural deficiency is what I believe you have. Where exactly it exists is uncertain without looking at it.
Can you give me some ideas about what kinds of people to talk to, or questions to ask, to figure out what the problem is and how to fix it?
How was the patch done where you removed the wall? Was any of the original ceiling board cut back?
A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Yes, some of the original ceiling was still there. I would say that about half the drywall on the current ceiling is new. One of the cracks in the ceiling runs along a joint between an old and new piece of drywall, and one runs between two new pieces. The corner I'm having trouble with is a mixture of new and old drywall, but in at least part of the area where the ceiling is pulling away from the wall, both pieces of drywall are old and never had a problem before the walls were changed.
If it is truss uplift, your best bet will be to not put drywall on them. I hate to say it, but removal of the problem areas might be your best bet. If it were me, Id take the entire ceiling down and fur down the ceiling (I like hat channel, but it is easy for me to get sometimes). Shimming the new furring strips, be they metal or wood, makes for I nice flat plane for the new sheetrock. When the old ceiling is down, you could add blocking, strongbacks, sisters, etc., to beef up the trusses before the furring goes in. I personally glue and screw drywall no matter where I hang it. I don't have to fuss so much with screw placement and depth of fasteners that way. The guy that recommends this to you is the guy you want to hire to do your sheetrock.
I had the impression that screwing drywall down tightly around the edges of the wall and ceiling was exactly the opposite of what should be done.
I just asked this very question in this thread: http://forums.taunton.com/tp-breaktime/messages?msg=124421.1.
According to Gypsum (http://www.gypsum.org/pdf/GA-216-07.pdf) the first screw should be 7" from the wall to help prevent the effects of truss uplift.
Yes, he has truss uplift!
Sounds like the trusses may have been designed with that bearing wall in mind. The architect may have just assumed a little too much originally. Was the ceiling patched with a small strip where the wall once was, or was it patched with full sheets?
It was patched with full sheets.
Go to a building materials yard and ask for the names of a few local drywallers. When you find someone who suggests that you need to address framing issues first, that's your guy.
Asking for a few client references is OK. Asking for free advice on how to fix a recurring problem during an "interview" isn't, at least IMHO.
My intention wasn't to get free advice. It was to ask some questions that might give me an idea of whether the people I was talking to knew something about how to deal with this kind of issue, and if they did, to hire them.
what you describe sounds like a classic case of truss uplift. There are environmental factors that cause some trusses to bow upwards and back down with the seasons. Usually where the cracks are seen most is at the intersection of wall and ceiling. This is why the gypsum board should not be screwed tight there in the ceiling. The other cracks are probably much finer and are more common when the mesh is used instead of tape. Do you know if your cieling was finished with mesh or with tape? Every time I have seen the fine longitudinal cracks it was with mesh.Here in the northeast, we do use strapping on the ceilings, which is running furring strips of 1x3 perpendicular to the framing, and then screw the SR to it. Somneone else mentioned hat track, the metal version of the same.These serve as an isolation barrier that absorbs some vibration and movement from structures above.You do not have a structural problem, but a normal deficiency that comes with trusses, tho yours sounds like it may be worse than some.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I remember that my drywaller used tape.What is SR?Do you think it's possible to fix this without tearing out the whole ceiling? And do you have any suggestions about how to find someone who is competent to fix the problem?
You could try a product like magic corner from Trim-Tex, but even that might not have enough flex.
SR is Sheet Rock a brand name of drywall.
Take a look at the attached document on truss uplift. Don't get too hung up on the use of those clips though. I've never seen them used and it is interesting that the truss industry often refers to them as a solution for truss uplift yet I have asked several truss manufacturers if they could get me some and they had none available. In the document they refer to truss uplift as "partition separation" which, to me is their terminology designed to take the focus off their product. :-) When reading the document take the "What causes..." portion with a grain of salt. Again, although these items are possible, I believe they are trying to take the focus off their product. Note though that the main thing is not to fasten the drywall to a truss close to an interior wall. Truss lift is caused by the seasonal shrinking and expansion of the lumber in the trusses, particularly the webs. This web page gives a simple pictorial explanation of that term "web." The drywall has to be able to flex to allow for this movement in the ceiling framing.
Truss uplift can be worsened by moisture problems in a home. These could include a bathroom or kitchen fan that are vented into the attic, improper roof ventilation, and even be a wet basement or crawl space.
Regarding the previous references to structural problems and trusses that need interior bearing walls it is unlikely, unless the span (overall length of the truss) is greater than maybe 40 or 50 feet.
If you want to explore further if one of the removed partitions was load bearing the first place to look is in the basement or crawl space to see if there is support all the way down to the concrete footings in the exact area where the partition(s) were removed above. Again though, it is unlikely.
Edited 9/17/2009 8:24 am ET by Matt
Piffin and Matt have it correct. Classic Trust uplift.
Your house probably has poor ventillation. This problem must be solved before the drywall problem can be fixed. In the winter, moisture in the attic is obsorbed into the trusses. The top truss expands from the cold and the bottom truss contracts. This situation can be avoided by better airflow.You get out of life what you put into it......minus taxes.
Marv
I hope that isn't the problem. As part of remodeling that area I tried to improve the ventilation and insulation. I did my best to seal all of the air leaks between the main floor and the attic, I added bathroom vents (there was no vent in the master bathroom and the vent in the second bathroom didn't work) and ran those vents out through the roof, and I added a ridge vent. I also blew in about R-70 worth of insulation into the attic (there was very little insulation there before) and I was careful to put in baffles in each bay to allow airflow to the eaves. I also resided the house with fiber cement siding and used their perforated boards under the eaves. If there is a ventilation problem, it wasn't for lack of trying.
The one thing that you did that might have contributed to the problem is the added insulation. This keeps the bottom chord of the truss warmer and moister than the rest of the truss members, which results in the differential expansion/contraction that causes uplift.But a few million other homes have similar insulation situations on trusses, without drywall separation problems.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
Yes on that one. This added quite a bit of weight too on the ceiling surface. That may now have a dead load of 20-30 lb / sf where most design criteria would have been for 10-15
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
It would take a lot of insulation to add up to 20#/sf. R70 would be on the order of 20" of cellulose, which would work out to 4-5 pounds per square foot.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
Your cieling dead load is not just the insulation. It is the gyp bd, and the cieling joists themselves, though I admit I don't know how that calculates when using trusses.I do figure this at just over 20" and about f#/sf when new, but my experience is that it does absorb and hold some moisture too.You are probably right on total load not going over the 15# normal when all is considered
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Put up some crown mold. Nail it only to the ceiling. Only caulk the ceiling joint. Have a nice day...
SR is SheetRock -- a brand name of drywall.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
SR = sheet rock = drywall = gypsum boardYou can run strapping @16" oc over the existing ( below it depending on point of view) with structural screws such as from GRK Canada penetrating the bottom chord of the trusses by 1-1/2" ( use 2-1/2" screws) to do this without removing the existing. You should think about trimming the joint wall-ceiling with a crown mold or bedmolding instead of taping to the wall
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
We just had our drywall completed in a new cottage build and are thrilled with the job done.
Our interior designer had recommend a painting/ woodworking crew to do all the finishing work. They inturn recommended the drywallers. As painters, they come in after and know who does good work. It makes the painters job easier if the drywall is done well. So if you know painters there is a good place to start.
PS By the way, I am from Canada, but have a friend in Naperville, nice place, loved the quaint little old downtown area.
What's the span of the trusses? Where the cracks are opening up at the ceiling corners, is that an outside wall, or an interior partition?
Generally, drywall should not be fastened tight to trusses within 6-10 inches of interior walls, but in theory "truss uplift" is not a problem at exterior walls.
The cracks perpendicular to the trusses are "normal", sorta. Not to say that they're expected, but they aren't that unusual.
The span is about 20 feet. The corner where I'm having the problem is an interior corner.
Yeah, that sounds like truss uplift. The drywall should be freed from the trusses within 8-10 inches of the wall. The problem, though, is that if this is patch work the ceiling drywall may not be lapping over the wall drywall, and so there's nothing to support the ceiling drywall save the fasteners.So it's a bit of a compromise either way.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
If the trusses are only 20 feet long then there's very little chance that they were designed on the expectation of a supporting wall in the center.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
I ain't no drywaller, but somewhere I've seen specs for drywalling onto a scissor truss roof, and it involved NOT screwing within so many inches of the joint, which allowed the taped corner and a few inches of dywalluw to move rather than break the joint. as the truss flexes with temp variations.
Not a place one would use the vario tapeless drywall system I guess.
http://www.edp-inc.net/
Eric in Calgary