So I've got a 2x10 Ledger attached to a concrete wall. I have a double 2x10 joist that needs to connect to the ledger. I have a joist hanger for this but the installation requirements say to use 16d nails (which are typically 3 1/2" long) to connect to the ledger. How can I do that if the ledger is only 1 1/2" thick? Will the nail go into the concrete? Are there shorter nails?