This article discusses strategies for building over an existing slab patio or over a deck and offers links to articles about the specific tasks such as pouring the footings raising posts and so forth.
Footings for deck roof.
Many porches use 22 diameter corner and intermediate footings.
If the deck doubles as a porch it needs to be able to support no more than 80 psf.
For an upper deck with a landscaped backyard below a belled pier may be the way to go providing for larger bearing areas but without as much concrete in the flowerbeds.
When you pour concrete footings hold the cardboard concrete form tube about 12 in.
Start here if you re building a roof over a patio or deck.
Learn everything you need to know about installing concrete footings to support your deck.
How to get a solid frost proof footing.
Then dump concrete through the tube into the bottom of the hole.
The footings for porch decks must be larger than deck footings.
Decks typically are designed to support 55 pounds per square feet or psf of weight.
Do this by nailing the sides of the tube to the center of a tic tac toe grid of 2x4s at the top of the hole.
Porch decks also require larger footings than deck footings.
Check out our deck footing frost map to help you understand how deep your footings will need to be excavated.
Up from the bottom of the footing.
Gable end porches will also require an additional footing in the center of the side rim to transfer the truss or rafter loads to the footings because the framing of the roof is perpendicular to the floor framing.