I will be installing fireblocking as part of finishing my basement. I plan to leave about an 8" gap between the newly framed walls (metal stud framing) and the cinder block foundation wall to avoid putting holes into the concrete covering the French drain for my sump pump. I will therefore be installing continuous runs of 2"x12" lumber to the bottom of the floor joists as fireblocking material before framing the walls underneath.
Is it better to use nails or screws to secure the 2"x12" lumber to the floor joists?
Using nails seems like it will work better with the shear loads from expansion and contraction of my otherwise wood-framed house. However, the lumber also has tensile loads from gravity for which screws are typically recommended. I am planning to use non-load bearing metal drywall studs to frame the wall beneath the fireblocking.