I am about to lay 1/2" APA Underlayment rated plywood down as an underlayment over 3/4" plywood subfloor for 1/2 strand woven bamboo.

I would prefer not to do it by hand as it would quite the task with laying 20 4x8 sheets. Any suggestions on suitable alternatives?

Also when lying the 1/2" underlayment am I correct in stating I do not need to leave an expansion gap more than 1/32" around the perimeter?

Thank you,
Chris

I use a framing gun with ring shank nails. as for the gap I go about 1/8 from the edge and about 1/16 between sheets. The fewer things you have touching the less of a chance of squeaks. you could also use a subfloor adhesive under the sheets.

Do they sell 1 1/4" ring shank nails for a nail gun?

Probably not you would have to check to see if there are any for whatever gun you would be using. But I go longer and nail into the joists.