One 2x10 joist carries a split running about 14 inches in from its bearing end, straight along the grain at mid-depth, wide enough to pass a fingernail. How should the inspector handle this member?
- AAccept it; a split in the end of a joist is closed by the bearing pressure and has no effect on how it carries load
Bearing pressure acts vertically at the support and does not close a horizontal split along the grain. The split remains a plane of separation through the depth of the member.
- BAccept it; the grade stamp on the joist governs, and a member that carries a stamp has already been judged acceptable
A grade stamp records the condition of the piece at the mill. Damage from handling, storage or weather afterward is the inspector's to judge, and it is not covered by the stamp.
- Reject the member; a split at the bearing end reduces shear capacity where shear is highest, so it must be replaced or reinforced
- DReject the member; every joist showing any check or split has to be replaced, since visible defects are not permitted in framing lumber
Checks and small surface splits are normal in seasoned lumber and are contemplated in the grading rules. Rejecting every visible defect would condemn most of the lumber on any job and is not what the code asks.
Why C is correct
Shear is highest at the supports, and a split along the grain at mid-depth separates the member on the plane where that shear acts. A 14-inch split at the bearing end therefore removes capacity where the joist needs it most, and the member is replaced or reinforced with an approved detail.
What this question is testing
Whether the candidate can judge a material defect on its own merits, relates the location of the defect to where shear governs, and distinguishes damage from the normal seasoning characteristics the grading rules already allow.
On the job
Splits at bearing ends come from lumber dropped off a truck, from banding that was cut while the bundle was stacked badly, and from joists left in the weather and then dried quickly. Inspectors look at the ends of members over supports, where a split does the most harm, and use a knife or a fingernail to judge depth. The repair is usually a full-depth scab or a hanger, which is cheap compared with replacing a joist under a finished floor.
Memory technique
Shear lives at the ends; keep the ends whole.
Exam tip
Where the defect sits matters as much as its size. Splits at supports attack shear.
Where to look it up
IRC Chapter 5, floors, the general requirements for lumber quality and identification.