Roofer hired to install two twisty vents to remediate heat in attic. He cut the upper 2×4 truss chord 1.5″ deep in two places about 10″ apart. He says its “OK” I say it needs repaired. I’d like to hear any third party opinions on this.
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From that picture it appears that the piece is badly split -- is that the case or is the picture fooling us?
I don't think that is a split
I believe what you're seeing are digitally added line graphics (black lines) that identifiy where the cuts are in the truss. A "photo shop" type mark-up, if you will.
I thought it was drawn on the truss with a Sharpie.
Of course iit was drawn with a Sharpie. How else would they know where to trace the line digitally?
Who ya gonna call?
Most wood trusses are not engineered to be cut to this degree w/o structural consequence.
Is your roofer also a professional engineer? If not, then on what professional basis has he determined that the truss is still structurally "OK"? He should keep in mind that the desire to abdicate responsibilty for one's potentially harmful actions do not absolve one from liability; that's called wishful thinking.
I'll give you one guess as to who you should call for a definitve answer to your query. Hint: It is someone with creditionals in their professional title.
BTW, my guess is that the remedy to restore any potential structural deficiency caused by these cuts is not going to be too involved or costly. If your roofer is reasonable, then you both should be able to work out an agreeable solution w/o the additional cost of an engineer.
Well, at least the guy's a better carpenter than most plumbers.
I designed roof trusses for ~25 years. My professional opinion is fix it.
But - I'd also suggest not making a federal case out of it. A board on each side maye 6' long, glued and screwed.
Indeed, small problem and
gussets will fix just fine. Doesn't look like 1.5" depth either, given the percentage of kerf across a 2x4. I would go 2x4 gusset extending a bit more to either side of the cuts than the cut section is long. Ten inches between cuts, extend twenty inches to either side of the cuts. Drop the gusset 3/4" below bottom of roof sheathing to not obstruct air flow.
Or, call a PE if it makes you sleep better. And then try getting the roofer to cough up the three hundred that the detail will run you. Just a thought here, but until the cord breaks you don't really have a problem. What you have now is worry about a potential problem. Just keep in mind that a two hundred pound body was walking and standing all over this area during install, and nothing broke. That's the equivalent load of... lots and lots of snow, and I think you could probably just monitor it for a while.
If it was my roof I would fix it in a few minutes with above gusset and never think about it ever again.
Why?
Were the cuts made in the first place? Too much of a hurry to set the saw depth to avoid cutting trusses?
From the pic I assume cuts are under the roof sheathing, the new vent's on top of the hole. Truss chords in this instance are in tension underneath (NO CUTS THERE!!!) but compression above. Adding scabs will block net available vent area to some degree but IMHO would be recommended, particularly if roof is low-pitched and you get significant snow loads in the winter.
I don't think the cuts were necessary in the first place (looking at the pic again later I think the roofer could have taken an extra five minutes to cut the sheathing without cutting it away from the truss?) but now that they're there you're better off if the trusses are strengthened than just letting them go....
Probably one could use 3/4"
Probably one could use 3/4" plywood rather than 2x and reduce the amount of obstruction while still sufficiently reenforcing the members.