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How to Attach Deck Roof Support Posts

63K views 66 replies 21 participants last post by  RobertCDF  
#1 ·
I have a client who wants a deck built approximately 10' off the ground with a roof. 20' 6x6 PT posts would be long enough to use as both deck support and roof support, but the expense isn't justified because all that is needed to support the roof would be 4x4s. I could frame the deck with 6x6s I can buy off the rack at the lumberyard and not have to special order something twice as expensive, but I am not sure how to attach the 4x4 posts that would support the roof to the deck framing. I have read that code allows toenail screwing through the roof posts, decking and into the framing provided they penetrate deck framing at least 2", but that just doesn't sound right to me.

Can anyone explain the proper, code approved way to attach 4x4 roof support posts to a deck 10' off the ground?
 
#3 ·
Well that depends entirely on what your local AHJ requires.

As far as I am aware there is no prescriptive code for a roof on a wood deck or details for same. That might then require engineering from a licensed engineer for your state. Perhaps the AHJ would allow a non-engineered solution but you would have to ask them first.

Andy.
 
#5 · (Edited)
#8 ·
there may or may not be different methods for doing this above a certain height, but simpson makes plenty of connectors and you can find some common ones at the local supply store or big box store.

notching the top of the post for one of beams, nailing it in then install the second over the first would work. Even though this could be built w 16d's, I might go ahead and use 1/2" carriage bolts.
 
#9 ·
So you're saying not to post and install the doubled up two by flush with the top of the post, then installing the roof post sitting directly on top of the deck post? Would I toenail that in? For another 40 bucks I could avoid any problems with that ever slipping out of place and go ahead and buy the 20 foot post


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#12 ·
I get those brackets made up for me at a local weld shop. They burn the holes in no need to drill them.

Around $50 per. Installed correctly there is 0 movement. We don't have to fret over things the way some do. Over here it's up to the Contractor to build it the way the Inspector wants it. Over the years I have built dozens of projects using the steel brackets.

JonMon www.deckmastersllc.com
 
#14 · (Edited)
I have to ask, how are you planning on supporting the deck beam if you run the post up to carry the cover?

I've ran the post down through the decking like Hyatt mentioned and used a Simpson MSTC28 on each side of the patio cover post. Then placed the post over the deck support beam. The strap "stradled" the deck beam and the post. I made sure they were laid out fully bearing over the deck post. So as to have transfer all the way to the footing.
Image
 
#18 ·
Think about it....The deck is 10' then you have anther load on top of that. The roof will be rigid due to the sheathing, but the weakest point would be any independent attachment to the deck which is already going to be sway prone due to the height above grade...adding the extra load of a roof complicates things. Diagonal decking would go a long way towards making the deck more rigid and less sway prone. Continuous posts from the roof to the footing transfers the roof load to the ground rather than the deck...this only makes sense and then the deck itself should be supported on a beam by separate posts

Trying to cheap out on posts and support on a job like this is asking for trouble....I won't do it....I wanna keep what I got
 
#63 ·
I have never seen these and I'm having trouble visualizing it for myself. Do you have a picture? I would love to be able to avoid diagonal bracing to give the deck a cleaner look and more durable racking resistance.


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#20 ·
Actually Mike. I install the brackets on the decking not through it. Grace tape on the bottom for isolation .

You got foundation, solid framing to catch the lag bolts , staggered holes for lagging the post to the bracket. This done = 0 movement from the posts.

The brackets increases the post size an inch . I trim the bottom out with what ever the decking is.

Not " cheeping out " at all Slave one.

J.
 
#25 · (Edited)
We have clay soil here so I have to spread all that weight out. Plus I wanted this deck to support a 80PSF live load to account for the extra roof weight. Here's my design so far.

16x12 deck.

18" footers and 12" tubes for post footings 14" deep plus 6" of gravel = 20" deep (frost line in GA is pretty shallow. It's supposed to be 60 degrees F here tonight!).

Deck beam 2@2x12. 4@6x6 post across the 16' deck beam and 1@6x6 post bisecting the span of the 12' rim joist on either side. 2x10 ledger and joists 16" O.C.

Notch the post 3" to hold the beam and continue the beam up to hold the roof, which will be a 4:12 pitch. 2x8 ridge, double 2x6 rafters with 1/2" spacer 4' O.C., (actually probably some kind of hand-build truss-ishness with fan plates) then T&G boards and roofing to match existing.

Do I need to continue all the posts up to the roof or just the corners to hold the roof header and rim joist posts to support rafter tails?

Since I am going to install trusses the ridge will be only decorative and won't be supporting any weight so I just need to make sure I have strong roof headers all the way around. How do I support the rear end of the roof header on the 12' sides? The deck roof will dive into the existing house wall, not tie into a roof.
 
#30 ·
We have clay soil here so I have to spread all that weight out. Plus I wanted this deck to support a 80PSF live load to account for the extra roof weight. Here's my design so far.

16x12 deck.

18" footers and 12" tubes for post footings 14" deep plus 6" of gravel = 20" deep (frost line in GA is pretty shallow. It's supposed to be 60 degrees F here tonight!).
What do you mean by "foundation?"
Im guessing he meant something beefier than you described, 14" of a 1' sonotube is not going to support that, no matter the frost line, I'm not sure of your background, and I know I am just some dude on the interwebs, but please let someone with experience design this before someone gets hurt when this blows over

That is indeed a thought and a very useful one at that. I tend to believe that time spent in planning and designing saves time and money during the build and leads to a safer, higher-quality finished product. Bonus if you can charge enough to cover your design time as an overhead cost.
yet what you are describing is not safer, please find a designer with experience, if you can cover design time as overhead, why cant the proper material be covered as "material cost"?
 
#28 ·
I have a client who wants a deck built approximately 10' off the ground with a roof. 20' 6x6 PT posts would be long enough to use as both deck support and roof support, but the expense isn't justified because all that is needed to support the roof would be 4x4s. I could frame the deck with 6x6s I can buy off the rack at the lumberyard and not have to special order something twice as expensive, but I am not sure how to attach the 4x4 posts that would support the roof to the deck framing. I have read that code allows toenail screwing through the roof posts, decking and into the framing provided they penetrate deck framing at least 2", but that just doesn't sound right to me.

Can anyone explain the proper, code approved way to attach 4x4 roof support posts to a deck 10' off the ground?
So time you're wasting trying to figure out how to do this multi-material mashup and metal, probably could have paid for the longer 6x6s and you'd be a day ahead or more. Just a thought.
 
#29 ·
That is indeed a thought and a very useful one at that. I tend to believe that time spent in planning and designing saves time and money during the build and leads to a safer, higher-quality finished product. Bonus if you can charge enough to cover your design time as an overhead cost.


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#38 ·
Thank you for your input. You seem like an experienced guy I could learn a lot from, but honestly it seems like you're taking more pleasure out of telling me I don't know what I'm doing. Just so you know, I plan to submit drawings to the building department, involve the inspector, and have a proper permit pulled. I am working towards getting my license, so I need to show the state board that I was responsible for two projects that required a permit. Nobody's going to build anything that isn't perfectly safe and doesn't exceed code requirements. I am here asking questions so I can get better at my craft.

I have built plenty of things outside using what's available at Home Depot, but I have never seen custom fabricated steel brackets and I am interested in learning about that. The way it has been described here by two different people just doesn't compute in my head. Is there anyone who would be willing to maybe talk with me on the phone or post a picture of this set up? A picture is worth 1000 words.




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#47 ·
A Man can use pt timbers, like 6x6'', as long as they are covered up in a timely nature.

20 footers would just be asking for trouble. I would build that thing, if I am visualizing correctly, like I would a house.

Starting with the deck . Square it up I usually put the perimeter up in a temporary nature, place the piers including the ones for the second story ( roof ) if the corners of the deck are the same as the roof the same piers used for the deck as the roof. Bolt down the steel U shaped brackets with anchors or two part Hilti. to the pier ( this is how Mike does it .. I land the brackets on the decking just to save time ) Bolt the 8' ( or whatever high they need to be ) posts to the brackets.

Then build the second story, Roof , landing your beams on top of the posts secured by regular post brackets. As soon as possible wrap all the posts with 3/4'' material. Special care taken with the 1/2'' steel brackets as they will have to be bigger than the post wrap which is ok cause most of the time the bottom of a post like that looks better bigger anywho.

Build the rest as is normally done. A lot of info you might not need or want. The main thing as I see it was the support for the posts. That heavy duty steel bracket will solve that issue with change to spare. No lift, No sway, and No wiggle. Any decent fabricator will square those brackets up and weld both sides but be sure you allow space for the always inconsistent measurements of pt lumber. 6x6'' could mean 5 3/4 '' or any variation of that, I have seen 6 1/4'' on what was supposed to be 5 1/2''.

Anyway good show with the Marines . The military is tough to go in and stay in , getting out is not all that easy either so good fortune to Ya.

J.
 
#50 ·
Just make sure the footers are up to snuff. I'd overdo it here as I've seen many a failure on these types of jobs.

With a deck and a roof you got a hell of a lot more point load than you think on those 6x6.

no store bought bagged conc...If you must beef it up with some portland and some real aggregate and don't forget the #5 or #6 bar
 
#55 ·
he can support it with telephone poles, I'm more concerned with what's underneath of it.

Lot's of so called deck builders run around here putting up stuff like this and use 12" sonotube and that $4 a bag concrete...which is nothing but a pinch of cement, some fly ash, and pea gravel