Here are examples of Ledgers for Newport Solid and Laguna Lattice aluminum patio covers.

This patio has both ledgers needed for a combination patio cover.

The 2.5″ roll formed hangers seen on the right is attached every 16″ oc with 4″ lag bolts
The 2×6 aluminum piece seen on the left has wood inside of it attache 16″ oc as well.

After this has been done you would call the city for a ledger inspection on you permit job card for the city to send an inspector out to make sure everything in being built to code.

Ledgers

Ledger Inspection