The joists lap about 1 inch past one another over the wall and are held with a single 8d toenail into the top plate, with nothing fastening the two lapped members to each other. How should the inspector judge this splice?
- AAccept it; the joists bear on the wall below them, so the connection between the two lapped lengths carries no load at all
Bearing is only half of what these members do. As rafter ties they carry tension along their length, and a connection that carries no tension breaks the tie in the middle.
- Reject it; the lapped ends must be joined so the tie is continuous, with the lap and nailing the schedule requires
- CAccept it; a lapped joist splice is complete once each member is toenailed to the plate it bears on
Toenailing to the plate holds the member in position vertically. It does nothing to connect the two lengths to each other, which is what the tie requires.
- DReject it; ceiling joists may not be spliced over a partition and must run in one length from wall to wall
Splices over a bearing partition are ordinary and permitted. The requirement is that the splice be made properly, not that the members run full length, which would be impractical on most houses.
Why B is correct
Ceiling joists that act as rafter ties are in tension, and the tension has to cross the splice over the bearing wall. The lapped ends must be lapped at least 3 inches and nailed to each other to the schedule, or joined with an approved splice, rather than merely toenailed to the plate.
What this question is testing
Whether the candidate recognizes ceiling joists doubling as rafter ties, understands the splice carries tension, and knows what a compliant lapped splice requires beyond bearing.
On the job
This is one of the most consequential defects an inspector can catch on a stick-framed roof, and it is nearly invisible from the attic hatch unless someone crawls over to the bearing wall. The symptoms appear years later as a sagging ridge, cracks over the exterior wall lines, and doors that stop closing. Adding a properly nailed lap or a splice plate takes minutes while the attic is open.
Memory technique
A tie with a broken middle is not a tie.
Exam tip
Ask what the ceiling joist is doing. If it is the rafter tie, the splice carries tension.
Where to look it up
IRC Chapter 8, roof framing, ceiling joists and rafter ties, with the fastening schedule for lapped members.