||03-24-2006 10:24 PM
Yes the nails will, and should, poke through the sheathing. In fact, they should come through about 1/4" this is what stops them from backing out. I always use 1-1/4" just because I find them easier to drive with less hitting of the fingers.
What type of roofing was on there originally? It's possible the previous roofer used 3/4" nails, they are available, but even with these you should be able to see the points on the inside. Read the shingle package, some manufacturers require the nails to come through 1/4"