27 YO house. Not sure if these issues were from construction, damaged over time, or possibly a defective design, with the exception of the bowed trusses, all the problems viewed were at the splice in the upper chords.
I counted 21 loose gusset plates at the upper chord splices on the front & rear sides, 5 bowed truss webs and 4 upper chords that had displaced materials.
Any and all comments welcome, especially SE comments.
Wow Kevin. Never seen anything like that.
One would think the damage all occurred by improper storage or mishandling, but that first picture seems to show one of the staples like it pulled down from the OSB which would indicate it happened after erection.
What was the distance from the splice to the ridge?
Pulling those splice plates out like that really needs quite a bit of work, and improper storage would show them pulled out and all bent.
Anxious to see what others think of this.
Tho odd thing about that joint is the plate and teeth are not bent. The plate had moved opposite the top chord. Almost looks like the plate was improperly installed. But that would be obvious to anyone looking at the truss. Ever try pulling a truss plate off? It’s a SOB and the plate gets mangled in the process. That many damaged trusses is unusual. I would try to pull down on the top chord to see if the nails lineup with its current position, which would indicate the damage was done before the roof sheathing was applied.
Randy, look at the first picture where you see the staple still in the truss. I would think it pull through the OSB, but have no idea how that could happen. Like I said originally, if the damage was down coming off the truck, the plates would be bent somewhat. Bad batch of wood for the plates to pull out??
In picture 1 it is obvious that the truss was damaged recently. You can see the dust outline of the truss plate on the top cord of the truss.The house is 27 years old and must have had a new roof recently and the roofer dropped the bundles of roofing on the roof damaging the roof truss. seen this happen many times.
That is pretty much no bueno. Fortunately each of those joints is readily repairable with structural plywood, if you know how to do truss and gusset plate calculations. One thing you can’t do is try to hand-hammer those metal plates back into position.
I’m leaning towards ventilation issue/excessive heat/moisture in the attic. I’ve see these blue striped mitek plates start coming loose from the center outwards at several houses too. Sometimes they are fine though. But it is weird, I don’t see other type of plates having this much frequency of coming loose. I wonder if there is an inherent problem with batches of the plates themselves. Really wish someone could take one of these loose suckers off and analyze the composition and see if there is some problem.
The defect could have come from the factory disguised as acceptable product. Then the delivery stressed the joints and separated. I have seen this exact issue before. As union carpenters back in the 80’s, we would have nailed the gussets back in place and nailed a stiffener along the side before installation. I think the framers of this building installed them just as the picture shows. The defect is repairable.
See this enlarged picture from one of Kevin’s original pictures. This is what I’m referring to and I see way too often. The bowed gusset plate and loose teeth that is present before the top truss chord twisted and busted the splice joint loose. I don’t think this truss was actually installed at the house with this splice joint loose. Even the worst framer isn’t blind enough to let a large loose joint stand like this when built, so I believe this is something that gradually happened over time. I often see a short 2x4 scab nailed on that really doesn’t do much to reinforce the joint, a single framing nail is used to hold the members together with loose plates, or some other really inadequate reinforcement applied when framers attempt to repair loose truss joints/plates or damage during construction, or just hide it long enough from city inspectors to pass the framing inspection. Overall, I think it’s less of a manufacture/assembly issue than issues with the plate, wood, and the environment the trusses are in. Think about it, trusses are pieced together on a flat platform, gusset plates are put over joints, then comes a roller(think steamroller but much smaller and longer) runs over the plates and voila its all connected together and the truss is done. Just doesn’t make sense for the plate to bow out from the center so smoothly when run over with a roller, unless there is some other method of truss assembly I’m not aware of?? Moisture and heat makes more sense…I mean why do new construction have nail pops all the time??? Cause the house settles, wood dries and gets wet again, HVAC gets turned on and dries framing, framing gets loaded, gaps/etc between framing members get compressed/open up, and so on. Well, only difference being instead of a generally cosmetic nail pop in a drywall issue, loose truss plates is a structural issue.