Final answer:
Web stiffeners should be nailed directly to the web of an I-joist over a girder as per the manufacturer's installation guidelines, which dictate the nail size, type, and pattern. It is crucial to use the specified materials and to follow the proper nailing technique to maintain structural integrity.
Step-by-step explanation:
When an I-joist runs continuously over a support, such as a girder, web stiffeners should be properly attached to ensure stability and structural integrity. The stiffeners must be nailed directly to the web of the I-joist at the location where it rests on the girder. Typically, manufacturers provide installation guidelines that include the size and type of nails to be used, as well as the correct nailing pattern. It's important to use the specified hardware and follow these instructions carefully to maintain the strength of the joist system and comply with building codes.
Furthermore, the stiffeners should be made of the same material grade and thickness as recommended by the joist manufacturer. While nailing, make sure not to overdrive nails as this can damage the stiffener or the joist's web. Consulting with a structural engineer or following construction documents is critical when working with structural components to ensure proper installation.