Carpentry Question: Roof over deck (aka porch).
 

Hi everyone,

I'm about to build a 8x12 porch onto my house. Simply a deck very close to
ground with a roof over it. My question has to do with exactly where to put
the posts that support the front edge of the roof (back goes into existing
roof). The deck frame will sit very close to the ground, 12 to 20 inches,
and be supported by 3 cement footers (sonotubes) and a ledger-board.

My first thought is to run the posts right down to the cement and use
anchors of some sort. Build the deck frame around that. This way, the roof
is independent of the deck, and anchored against upward forces such as wind.
Disadvantage is that I've got to get my footings exactly in the right spot
for the roof posts. Am I capable of getting that perfect I wonder to myself.

I've spent the last few months looking at other porches, porch repairs and
new construction and it looks like the decks are built first, then the posts
come down and sit on the deck framing? This certainly would make any small
placement adjustments with the posts easier, and the deck framing would be
sitting right on the cement below the posts. But, would the posts be
anchored properly this way?

Any advice on this would be appreciated.

-Jeff

John wrote:
Hi everyone,

I'm about to build a 8x12 porch onto my house. Simply a deck very close to
ground with a roof over it. My question has to do with exactly where to put
the posts that support the front edge of the roof (back goes into existing
roof). The deck frame will sit very close to the ground, 12 to 20 inches,
and be supported by 3 cement footers (sonotubes) and a ledger-board.

My first thought is to run the posts right down to the cement and use
anchors of some sort. Build the deck frame around that. This way, the roof
is independent of the deck, and anchored against upward forces such as wind.
Disadvantage is that I've got to get my footings exactly in the right spot
for the roof posts. Am I capable of getting that perfect I wonder to myself.

I've spent the last few months looking at other porches, porch repairs and
new construction and it looks like the decks are built first, then the posts
come down and sit on the deck framing? This certainly would make any small
placement adjustments with the posts easier, and the deck framing would be
sitting right on the cement below the posts. But, would the posts be
anchored properly this way?

Any advice on this would be appreciated.

It's really not a big deal to have the posts support the deck framing
and the roof, and, as you noted, it's the easiest way to tie the roof
down.

When you place the concrete in your sonotubes stick in an anchor bolt,
then use one of the adjustable post bases. They have an oblong hole
that allows you to slide it around until it's lined up. Then tighten
the nut. Check the Simpson Strongtie web site for the specifics.

I like to notch out the posts a bit to accept the deck beam - one on
either side of the post - and the whole shebang is through-bolted.

R

Your footings need to be accurately placed anyway (I just finished a deck
project myself). You just lay everything out with layout strings ahead of
time. Any good deck book will step you through this process.

I'd personally want to run the roof supports down to the concrete, not to
the decking, but I like to overengineer...

-Tim