Misaligned trusses

[kb57442]

Hi,
Found this site as I was looking for an answer to a question.
I'm building a 26x50 garage and installed the trusses with my wife and 3 teenage boys. I measured the bottom chord length and they were all the same. So I straitened the walls and had one of the boys match the end of the truss to the end of the bottom chord. This is a 14 foot ceiling with attic trusses so the total height is 22' to the peak. I really didn't have a way of stringing the peak with the number of people/time I had to install the trusses (we used a crane and it took us over 6 hours.)
Anyway.. now that I've strung a line down the peak I can see the trusses aren't lining up perfectly. There's about 1/2" or so of variance to the left or the right of the string. I haven't measured each one but it's possible there is 1" in some places.

The misalignment isn't totally hap hazard. most trusses are fairly aligned to the adjacent trusses but the peak is wavy as you sight down it.

My question is... how much of a problem is this going to cause me as I put the sheathing on the roof? Is it imperative that I fix it or is it mostly a cosmetic problem? Last time I did this was when I was in my late teens / early 20's and we had rafters, not trusses. Now I'm much older but evidently not wiser.

Any suggestions or help would be appreciated.

 

[kd3pc]

you ca lose a bit of the wobble down the line, by using a ridge vent...I usually cut 2-3" off each side of the OSB, below the truss peak - making sure there is a good clear path, shingle to the ridge and over, and then cut out for my ridge vent....it will erase an inch or better of out of line.

Might work for you.

 

[The Cobbler]

I think the issue will be more noticeable at the soffit , not the peak .

shim a bit as others have said if you can't align them better

 

[Hot Rod Grampa]

Are the walls stiff? Are they perfectly plumb? You might be able to lean on the wall with a few braces to bring the ridge into alignment. One 8 foot sheet at a time. Nail it off at the ridge first then move over and do the next 8 feet. Repeat. A local builder uses comealongs inside diagonally to pull building straight. Just thinking out loud.

 

[matt_i]

I would run the string over the "plane" of each side about 4-6" down from the peak, on each side of the ridge for comparison. This is what you might see from the outside. I would think you may be OK as long as the +1/2" isn't right next door to the -1/2".

As mentioned above, if you used a ridge vent you'll never see the peaks. However it could be helpful to snap a line on the roofing each side to help align the ridge vent. Architechtural shingles would also do well at hiding anything due to their "random" pattern as opposed to the "perfect brick wall" of the 3 tabbers.

I snapped a line on top of the tails and screwed together a plywood/wood jig that was moved to each truss as a saw guide for sawing all the tails to the same length, so the soffit would not have any wow or wave. To start the snapped line, I measured out from the sidewall/double top plate equidistant on both ends and then transferred this up to the inclined plane via level.

 

[red61cj5]

too late now, but instead of stringing the peak, I string the tails, works fine as long as the walls are straight.

 

[Kaizen]

I ran into that but worse. Stringing a line along the eaves on mine I actually had to trim some and add spacers behind the eave board. I was concerned the roof would be wavy but after sheathing i couldn't notice. After roofing it no way. What you do need to make sure are correct is the truss spacing from each other. I installed mine alone so I had some issues with spacing and as I put them up six months ago some warped. I used a bar clamp and a ratchet strap to move some around. Mine is 22 feet as well. Get a safety harness that is up there.



Sent from my iPhone using Tapatalk

 

[Firebrick43]

My icf house that I am building is 28x80 including the garage. We strung the tails and had 3/4" out in places. Scratched my head for a while and figured out it was the trusses them selves. Three off them were off. One I was able to shim. I used architectural shingles and no one can see the worst of the dip except me but I know exactly where it is. I can even point it out and others really can't see it.

 

[Majordisorder]

"So I straitened the walls and had one of the boys match the end of the truss to the end of the bottom chord."

This isn't exactly clear but normally you would "plumb and line" your walls, then set the trusses based on the bottom cord of the truss. Typically the end of the truss bottom cord would sit even with the top plate outer face, or wall sheathing depending on what was used for the building width dimension.

If the trusses are shifted, your biggest problem will be at the eave and sub facia. Snapping a line and trimming the tails might be necessary.

Is it possible that any trusses got rotated 180 deg.? This could create some shifting as well.

 

[Binkie]

I made the mistake of not stringing the peaks, I know we did something to line them up, but it wasn't the peak. Realized after I blocked. Wasn't enough to fix by shimming, so I carried on without doing anything. It was a real ***** to sheath properly, had to trim a bunch, nothing was square because of this rookie f-up. But It looks fine now, all shingled, 8 years later.

Someone above suggested trying to fix the worst ones at the least, good idea. Fixing the foundation you will build upon is always a good idea. One hour fixing one thing often prevents spending three more one hour fix jobs, trust me.

 

[kb57442]

I ended up fixing the worse ones. They aren't all perfect but at most I probably have 1/4" to 1/2" off. I put a ridge vent on so the OSB didn't have to align.

 

[MikeF2316]

I ended up fixing the worse ones. They aren't all perfect but at most I probably have 1/4" to 1/2" off. I put a ridge vent on so the OSB didn't have to align.

Looks great from this angle!