Minimum Nailing Requirements for Web Stiffeners – Canada

Web stiffeners are required:

  • When sides of the hangers do not laterally brace the top flange of each P3 Joist;
  • When P3 Joist are designed to support unfactored concentrated loads greater than 1500 lbs. that are
    applied to the P3 Joist’s top flange between supports, the gap between the load stiffener and the flange shall be at the bottom flange;
  • For all engineered applications with end-reactions greater than 1500 lbs. A design analysis must be performed for all engineered applications with end-reactions greater than 1580 lbs.

When used at end bearings, install web stiffeners tightly against the bottom flange of the I-joist. Leave a minimum
1/8” gap between the top of the stiffener and the bottom of the top flange. See Figure 8.

Web stiffeners may be supplied by the distributor for field installation or may be cut in the field as required.


Stiffener Size and Nailing Requirement
Joist Depth 2-1/2″ Wide Flange
8d (2-1/2″) nails
3-1/2″ Wide Flange
10d (3″) nails
 9-1/2″ 4
 11-7/8″ 4 4
 14″ 4 4
 16″ 4 4
 18″ 6
 20″ 6
 22″ 8
 24″ 8
 Minimum Stiffener  1″ x 2-5/16″ (width)  1-1/2″ x 2-5/16″ (width)