Help.
I have both truss uplift and down shove that meets in the middle of the ceiling of the master bath. My house is like two large squares with a valley where the two roofs meet. The sissor kick trusses for the larger part of the house are a 30 foot span. They run north and south, and lever on the central wall. These end 2 feet south of the wall. They push up on the long 30 foot span in the large part of the house and push down on the 2 foot span that comes into the master bath. Thus they produce downward movement in the master bath. The east west trusses are flat ceiling and run 22 feet between the walls. The problem is that in the winter the east west part of the trusses rise while the north south part levers on the wall and move down. Together they create up to a 1/2 inch gap out of flat. Last spring I redid the ceiling so that the drywall covers the gap and backed off the screws 9 inches. This did not work – I am still getting cracking in the textured ceiling, both at the joint and at the pressure point.
Replies
cathy, I 'fixed' a house that had levitating trusses by running crown molding, attaching it to the ceiling, but not the wall - up or down, hides the movement...
Cathy -
You didn't really ask a question, but I assume you're looking for some solutions since you brought it up?
You use some phrases I'm not familiar with - I have no idea what you mean by "scissor kick trusses" or "down shove".
Some pictures of the exterior of the house would help a bit, if you have any available.
I did an extensive thread about truss uplift a while back. Here's a link to it:
http://forums.taunton.com/n/mb/message.asp?webtag=tp-breaktime&msg=24607.1
According to a recent survey, men say the first thing they notice about a woman is their eyes.
And women say the first thing they notice about men is they're a bunch of liars.
Hello Mr. Doud and Mr. Hog
Thank you. Yes. I guess my question was how to fix it. Thank you for the information. It sounds like I should do more ventilation.
I don't think crown molding will help much because the joint between the trusses is in the middle of the ceiling. The corner crack between the wall and ceiling is very small by comparison
Re. attic ventilation: Is the following sufficient? If not do I need an added vent - or what? [I have this mental image of myself adding ventilation to the front, waiting a year, adding it to the back, and finally 5 years from now adding a cupola.] There are 3 2" holes with wire across them in each 2 foot gap between the trusses, where the roof hits the house. There is about a 1/4" gap provided by a little metal form (which has asphalt shingles bent over the form but not closing it) at the top of the roof that was supposed to also provide ventilation. I don't think the insulation blocked the roofline holes. The contractor put cardboard blocks shaped like a 4 inch trough along the bottom of the roofline between each truss to keep the 2 inch holes clear of insulation. It acts like a little duct.
A short aside on the name.
My Dad was once angry with my little brother (5) and told him he was being a pig at the table. He asked him if he knew what a pig was. With a mournful look my brother nodded his head and said "A pig is the son of a Hog." It was one of the few times my Dad was at a loss for words. I've been fond of pigs and hogs ever since.
CathyC
Thanks for the added info here and via email. The pictures helped a great deal. I thought about posting them here on the forum, but wasn't sure if that would be O.K. with you or not.
For starters, I don't like the way your trusses were done. Cantilevering trusses out into the middle of a room is a bad idea. Poor judgement on the part of the truss company. But there's not a lot you can do about it now.
Sounds like you have a place for the air to get into your attic, through the "bird blocks" with screened holes in them. I assume the "little metal form" you mention is some sort of ridge vent. It must be pretty narrow if it only has a 1/4" gap. So it's possible that lack of ventilation is part of the problem.
You mention bathroom moisture - Do you have a bath exhaust fan? If so, is it vented into the attic, or outside? If it goes into the attic, that could be a significant part of your problem.
As for fixing the problem - You mentioned that you were thinking about screwing plywood to the ceiling and then adding drywall over it again. I don't really see any reason to add the plywood.
My suggestion would be to run 2X4 nailers screwed to the ceiling and hang new drywall from that. The nailers would allow the drywall a place to flex a bit.
Or as you mentioned in your email, framing a new ceiling that hangs from ledgers on the walls. But that way you lose some headroom.
Maybe some of the other folks here will have some additional suggestions.
Sounds like you're in Washington State somewhere? If you want to post where you're located, there could be someone near you who could make some recommendations specific to your location.
BTW - I loved the "Son of a hog" story. Definitely a keeper. (-:Politics is the art of looking for trouble, finding it, misdiagnosing it and then misapplying the wrong remedies.