Decks, Patios, Porches and Docks - What size bit for 1/2" carriage bolt

I need to drill holes through my brick and house band board to mount my ledger for my deck. I'm using 1/2" carriage bolts. What size masonry and wood bits do I need? Do I just use 1/2" or 9/16"?

hi
If your going to mount that board to the house thru the plate you have the wrong bolt.
you need is a lag screw that is like a big screw.
the hole is a little smaller than 1/2 so the screw has something to grip
If you need some shield anchor you will need bigger than 1/2 in.
Take your carriage bolt to the hardware and ask the clerk for advice.

pg

If going through a brick exterior and into the band board, use the 1/2" bit. I assume it's an older home with 3/4" thick rim joist/band board/ribbon board/etc...so lags will not work in this application since there is not enough meat in the wood for secure mounting and through bolting is the only alternative.

It may be easier to use a 9/16" masonary bit to bore through the brick facade then step down to 1/2" for going through the wood, but I'd try the 1/2" first and see how well it goes, would save you alot of time changin bits drilling holes twice.

IHI is correct. Even if your rim joist is a 2X, there's still not enough wood for a lag bolt to work. Through bolt thru the brick and the rim joist, and use at least a 2" sq. washer on the inside of the rim joist under the nut.