Building roof over deck. 4x4 bracket question?

greaserig · 10-03-2010, 09:03 PM

I'm building a roof over an existing deck and would like know the best way to mount the 4x4 roof support posts to the existing deck. I have some metal U shaped brackets but they look too flimsy to me. I plan to put in angle supports as well, but would like advice on the actual mounting of the 4x4 to the deck.
Any suggestions?
thanks

Tom Struble · 10-03-2010, 09:54 PM

you can't just mount the post to the deck,the load has to be carried to the footings,which may be too small for the deck and roof....building dept

greaserig · 10-04-2010, 12:19 AM

Thanks, the posts are to be mounted directly above the footings. The footings are the same size (actually a bit bigger as i dug them a bit deeper due to the hillside) as the rest of the building.
Assuming that i were to mount the posts to the deck my question is which is the best way to do it.

jlhaslip · 10-04-2010, 09:00 AM

If it was me doing this, I'd pull a few deck boards, run the posts down to the beam and attach the posts to joists/blocking.

Daniel Holzman · 10-04-2010, 10:57 AM

I assume you don't need a permit for this, else you would be discussing this consturction with the building inspector. So that said, I agree with jlhaslip, you need to connect the post to the beam directly above the existing post. This suggests using a Simpson post bracket attached to the beam. This assumes your footing is adequately sized, your existing post is adequately sized, your beam can handle the point load of the column, the bracket for the new column is appropriately sized, and the column is correctly sized for the roof load.

greaserig · 10-04-2010, 02:27 PM

Daniel and jlhaslip, this makes a lot of sense.
question: If i mount the posts to the joists/blocking is there some way to keep moisture from getting trapped where the post meets the joist? Would using Simpson brackets solve this problem?

Daniel Holzman · 10-04-2010, 07:27 PM

Simpson makes at least three different post support brackets. Check their website, see which post support makes the most sense for you. All of their brackets are designed to keep the post above the beam, but your application is a little unusual, so look at all the options before deciding which bracket is the best. I just installed a series of posts for my new deck using Simpson post support brackets, they provide a standoff of approximately 3/4 inch between the top of the concrete pier and the post. That particular bracket would not work in your case, because it is designed for embedment in concrete, but as I said they make lots of different shapes for a wide range of applications.

jlhaslip · 10-04-2010, 10:35 PM

Daniel has a great idea. Check the Simpson catalogue.

I have used a piece of shingle under a post to avoid water wicking up the post. It might be suitable for your application.
Are you using pressure treated?

greaserig · 10-05-2010, 04:53 PM

ahh!... perfect, the Simpson catalog! i should have thought of that! ha

Then i can plan the details before driving into town (about an hour and half from here).
I like the metal standoff and was thinking of putting washers between vertical joints? or maybe a piece of roofing felt, but i don't know if that would help or hurt. Now i'm thinking maybe a shingle would be better?
(not pressure treated but it will be under the roof and i'm painting the facing/undersides before fastening anything together.)
Thanks for your help