If the I-joist is a TJI, and only 1-1/2" thick with an engineered top and bottom chord, 8d nails are the maximum size to be used into those places. As Kc said, nailing into the web is recommended. If the chords are 1-3/4" or thicker, one (1), 10d nail is allowed into the top and bottom chord with 6"on center so as not to split the laminated chords.
This from installing blocking panels, face-nailing the top or bottom chords:
1. Details shown are for minimum blocking attachment. Transfer of lateral loads
may require additional fasteners. In such cases, nail size, spacing and specific
design detailing shall be provided by the building designer.
2. Common nails of the same pennyweight may be substituted for the box nails
3. Where blocking is required between adjacent joists, the blocking panels may be
staggered by approximately 6 inches for LVL flange and 3 inches for lumber
flange, and end-nailed as shown in A, B, or C. If the blocking panels must be
kept in alignment because they are being used to provide diaphragm blocking for
the wood structural panels above, toenails may be used to hold them in place
until the diaphragm nailing is completed."
Be safe, Gary
Clothes taking longer to dry?
Clean the dryer screen in HOT water if using fabric softener sheets.
They leave a residue that impedes air-flow, costing you money.
Clean the ducting in the last six months? 17,000 dryer fires annually!