April 16, 2015
In my report I stated ...
R301.1.3 Engineered design:
When a building of otherwise conventional construction contains structural elements exceeding the limits of Section R301 “Buildings and structures, and all parts thereof, shall be constructed to safely support all loads, including dead loads, live loads, roof loads, flood loads, snow loads, wind loads and seismic loads…” or otherwise not conforming to this code, these elements shall be designed in accordance with accepted engineering practice. The extent of such design need only demonstrate compliance of nonconventional elements with other applicable provisions and shall be compatible with the performance of the conventional framed system. Engineered design in accordance with the International Building Code (ICC) is permitted for all buildings and structures, and parts thereof, included in the scope of this code.
In the event that the client/ permit applicant would like to modify the structure’s load path from a load bearing wall to a ceiling joist (Valley Purlin Bracing “45 degree horizontal, and not vertical” – R802.5.1), we strongly recommend speaking with a structural engineer as this might be of a concern regarding load transfer. Our concern is on the left side of the ceiling joist is toe nailed to a triple 2 x 12 beam with “No Joist Hanger”, and the right side of the ceiling joist sits on the exterior load bearing wall. We recommend to re-framing from putting pressure 1/3 of the center of the ceiling joist (compression). Another concern is the triple beam and its transfer of loads to the studs “is the studs adequate to sub-stain the extra load”. Valley purlin bracing may have more pressure than a hip purlin bracing.
I did speak with the local city inspector and he gave me some options (sister up on ceiling joist and 5' strong back), but I didn't want to over step my boundaries and took the liability off my hands.
April 7, 2015
That question should be sent to an engineer for review. I am sure if an inspector allows something and problems become evident in the future, some one will want compensation. Also inspectors are not normally engineers.
April 16, 2015
During my inspection, the owner never knew why the house never came with a vented kitchen range vent hood and when I went to look in the attic, I noticed that the purlin bracing that was supporting the valley was crossing over the ceiling joist and resting on the top plate transferring the load down the load bearing wall leaving no room to place an exhaust vent.
When the contractor commented that he will place the purlin bracing in a 90 degree "vertical" on a single 2x10 ceiling joist stating that a 90 degree is stronger than a 45 degree horizontal, I stated in R802.5.1, states for horizontal and not vertical. We both came into agreement that the reason why the purlin bracing was not in a 90 degree is because it needs to be installed on a bearing wall. (NOTE: Rafters & Ceiling Joist is parallel)
Now my question is if the ceiling joist on the left end is nailed to a (triple) 2x12 with "no joist hanger", were as the right side is resting on the exterior bearing wall and a 90 degree purlin support is installed on the center 1/3 (compression) of a single 2x10 ceiling joist, is future problem with structural or drywall should be expected and if so what is your opinion?