The Deck Professor

Lessons / Ledger and attachment

Guess first

Metals that corrode each other

Guess what happens where these metals meet, then try each flashing
Flashing
Show a hint

Aluminum flashing laid straight onto the treated ledger.

Every number here is a working estimate. Check it with your building authority.Turn JavaScript on to work the lesson. The drawing shows how it starts.

The rule this lesson teaches

Aluminum flashing corrodes against treated wood and against galvanized fasteners.

Read the answer

Words in this lesson

Sources