Hey folks. Just registered and this is my first post here. I have a question about staple lengths. I've been reading online and don't think I really found a great answer.

My house has 5/8" ply as a subfloor, which then had 5/8" particle board as an underlayment with carpet over that. I ripped out the carpet and the particle board and will be installing 3/4" plywood or maybe Advantech over the the 5/8" ply. My finish floor will be a 5/8" solid bamboo.

My question is about the staple length. Considering my subfloor/underlayment will be nearly 1 3/8" thick, should I use 2" staples and penetrate through the the top 3/4" layer and into the 5/8" below, or use 1 1/2" staples and only fasten to the top 3/4" layer?

I already have and will be using a Bostitch MIIIFS stapler.

Id go for the 2".