Guess we will just have to agree to disagree OldBldgGuy. RE: Collar Tied Roof Fail OldBldgGuy (Structural) 5 Apr 19 00:04 I also know from actually being in construction for several years, most contractors I met disliked us and for some reason, almost insist on doing something not per our drawing for some really strange reason. I told him to correct it, but whether he did it or he made his boss do it "was optional". I asked him to show me where in my drawings it said detail C is optional. My favorite was "my boss said that was optional". Of that 60%, on half of them the contractor "did not see a need for that". The track record on the ones I have been asked to go back and review, easily 60% had something wrong that had to be corrected. So, you could look at one my projects, see crap, but it may be because the contractor did not do as instructed. On those projects, I have no idea if it was installed per my instructions. I have done designs but not been paid to review the final product. If I saw an absolute train wreck in the making, I would be more aggressive, but have never been faced with that. In those cases, I had a "suspicion" but it was not verified. I have done that and I have documented I made the call. If I do not do enough investigation before I report someone, I feel like I am treating them unfairly and would not want to be treated that way myself. I am yet to report one but have run into work I honestly felt was substandard but fortunately for me, no one was paying my time to investigate enough to make a valid accusation. RE: Collar Tied Roof Fail Ron247 (Structural) 4 Apr 19 14:00ĬANPRO, as far as reporting another engineer, I bet all of us have wrestled with that. The snow part of that definition I have never heard, but I am in a 5 psf snow area. A collar tie is a tension tie in the upper third of opposing gable rafters that is intended to resist rafter separation from the ridge beam during periods of unbalanced loads, such as that caused by wind uplift, or unbalanced roof loads from snow. This is a definition from the internet: Collar ties and rafter ties are examples of tension members. When I do have to do roof framing as an engineer, I actually state they must be at a specific location or range that suits me. Worse than having to duck down a little, is having to get down on your kneels to crawl under or attempt to step over the low ones. For those of you putting them in the lower third, I am sure someone has cussed about that. Once you nail them too low, anyone in the attic has to deal with them for the life of the house. The most comfortable place for nailing was about shoulder level but above the head was not that much harder. Real aggravating to walk thru an attic and have to duck down every 4' while crossing over ceiling joists. When I was a carpenter years ago, in addition to upper third, we also made sure we placed them at least above head level and preferred them close to the ridge from a material usage standpoint. To my knowledge, collar ties are not intended to serve as tension ties at all as related to what a ceiling joist provides. Watch some wind disaster video and you see an entire side of a roof lift up and disconnect from the other side.
To my knowledge they are only intended to keep the ridge from separating in a high wind.
#COLLAR TIES VS RAFTER TIES CODE#
They must be spaced no more than 4 feet (1219 mm) apart. They must be at least 1 inch by 4 inches (25 mm by 102 mm). If collar ties or ridge straps are installed to connect opposing rafters, they must be located in the upper third of the attic space. Ridge straps are permitted to replace collar ties.