Rules for Notches

General Limitations

TJI® Single Ply
Notch will only be allowed in a TJI joist member of one ply.

One Notch per joist
TJI product can only have one notch per joist member.

Notch Dimension
Notch will only be analyzed when the length parallel to the joist member span does not exceed 4 inches.

Notch will only be analyzed when the total cross-sectional ratio, of notch to flange area, is less than or equal to 50%.

Sloped Joist Member
Notch will only be allowed in a non-sloped TJI® joist member.

Notch too close to holes

Notch centerline of a top or bottom flange notch may not be located within 6 inches of the edge of slotted or rectangular hole.

It is important to note that manufactured knockouts can be placed in the 'no hole zone'

Notch too close to point loads

The total absolute magnitude of all point loads within the 6-inch zone from the centerline of the top flange notch, are limited to 100 lbs (IBC) and 145 lbs (NBC), when placed in load combinations. If those magnitudes are exceeded, then the notch will fail.

Notch too close to support

A bottom flange notch is limited to 6 inches from centerline of notch to edge of support.

Notch Design

A notch can have two separate moment capacities, a compression capacity and a tension capacity. For a single span member, the tension capacity becomes irrelevant. For a multi-span member, the notch can be in compression or tension based on the load combination and load pattern. If either of the capacity checks fail, the notch will fail.