The past couple of inspections, I have come across a situation where the ridge beam is not a continuos length from the gable on one side of the house to the gable on the other side of the house. The ridge beam is in two sections just butted up against each other approx in the middle of the house. There are no supports under this joint to safely bring the two butted beams to the load bearing walls below.
The ridge beam is suppose to hold up the rafters. In these cases I feel that the rafters are holding up the ridge beams.
The span is about 60 feet. Why would a framer not run a continuos length of a beam gable to gable?
If the rafters are directly opposite each other than it’s a ridge board not a ridge beam and it only aids in placing the rafters, no structural function. Many older houses were framed without a ridge board. If the rafters are NOT directly opposite then it is considered a ridge beam and should be designed to take the bending forces created by the offset rafters.
all right, quit being so damn picky! I’m using his terminology right wrong or indifferent. I don’t want to confuse them any more than they already are.
Rick, I always call out an unsupported ridge when it has a splice/joint in it. I have here a link to a photo from an inspection showing the ridge with a joint in it with only a brace to one side, instead of directley below the joint, with the unbraced side appearing to have dropped. http://www.jwkhomeinspections.com/roof/frame/bracing/ridge/braces/home/inspector/floresville/texas.html This is an example of why there is no reason why a ridge with a joint in it should not be braced either directly under it or on each side. It didn’t help in this case that there were no collar ties in this roof frame. So, I do always call out no bracing under a joint in the ridge. How tough would it be for framers to have thrown in a brace under a joint as they went along with the frame?
You are very correct in most cases. I depends on the roof design. Some trusses or monolithic trusses only go part of the way for design features. If you build a duplex and the peak is in the middle of the home the trusses mono’s will sit on the common wall with a 1 inch air space inbetween. This is just an example of the truss bearing on an interior wall.
You are correct that trusses are designed to send the load to the outside walls, but the other floor joists will still bear on the central load bearing wall.
There are exceptions to this(in very small homes), but in most platform framing the span of the first or second floor joists will be divided at the load bearing wall. It is possible the illustration is referring to the highest level as a load bearing to eliminate confusion, but there are some truss situations which will use that wall to support load. (cathedral, vaulted or a mix of trusses and rafters would be some examples)
So everyone here is exemplifying the need for threads like this.
I have to agree with post # 11 to a degree.
Torsion, tension and compaction, shear, and all other live or dead load forces should be worked on at once when you see your reasoning or structural hypotheses needs further studies.
