Re: Attaching deck ledger
the reasoning behind staggering lag bolts high and low is for when fastening them into a rim board, staggering them makes for less stress on one board so that it doesn't via having several bolts close toghether.. though not advised to drive bolts into end grain having them closer together wont cause an issue as each pair of bolts or screws are going into seperate peices of wood.. it should be fine just as long as the contractor predrills for large screws. driving large bolts into wood without a proper sized pilot holes causees the wood to split and even shear off the bolt if a impact driver or wrench is used.
another major thing that you should make sure of is that the contractor water proofs behind the ledger before its fastened. i use either 12" vycor or blueskin, another option is ice and water shield. once the ledger is on it should be properly flashed with a metal cap flashing.. if aluminum is used it shouldnt come in direct contact with the pressure treated lumber as it will eat the aluminum
fire up the saw and make some dust