I'm figuring out the lag screw size and spacing for attachment of ledger for a patio cover. At this time I don't know what the city will approve, but I'd like to be prepared in case they want me to use 1/2" lags. Most of the lags will go into a 2x12 header, but a few of them may need to go into 2x4 studs. I have access to the inside of the wall so can get the exact position of the stud and hit it dead center. Of course I will predrill. How do you feel about 1/2" lags into 2x4 studs in this scenario?

 

Are you planning on the lag bolts to go into the 2-inch (nominal) dimension or through the wider dimension? My personal opinion is that 1-1/2 inches of "meat" is not enough to give any real strength regardless of the dimension. As long as you are able to get to both sides I would recommend using carriage bolts with nuts and washers. And if you are going into the narrow dimension I would not use anything larger than 3/8 inch bolts or lags.

Others may have different opinions.

 

Carriage bolts and washers are often local code requirements - lag screws/bolt into a ledger board are often viewed as inadequate. I'd talk to the city sooner rather than later.

 

stickshift - no carriage bolts required here.

Furd - Yes, they are into the narrow side if the 2x4. I'm not comfortable with 1/2" for that either, so I'd like to use 3/8" for those.

 

I'd consider using Ledgerlok bolts before 1/2" lags, as they are far less likely to split the studs.

 

What Bridgman said x 2.......

 

My contact in the city plans inspection dept said they will require 1/2" lags @16", and referenced the IRC requirements for deck ledgers. Seriously? This is a patio cover with a total DL+LL of 30psf, not 50psf like for a deck.

Now, this guy is just advising me BEFORE I submit a permit request, so maybe he's being extra conservative so he doesn't say anything that might not pass approval. Or maybe he really doesn't know.

I think I'm going to reconsider my idea for a self-supporting structure with a second (inner) beam near the house, instead of a ledger.

In any case, I'm not sure I should ask this guy anymore questions.

If this is any indication of how these guys work, I can hardly wait to see what they say when I submit my plans.

 

Not a fan of punching holes in houses so I can easily get on board with this plan.

 

The odd thing here is that the city still requires self-supporting shade structures to be attached, but the attachment can be non-load bearing.