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Old 11-23-2011, 02:27 AM   #1
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Post size for an 10x12 freestanding patio cover


WHat is the required post size for a 10' high 10'x12' freestanding patio cover with 4 posts? Can I get away with 4"x4"s. the post brackets will be anchored in concrete. Should I use 6"x6"?

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Old 11-23-2011, 02:49 AM   #2
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Post size for an 10x12 freestanding patio cover


Well, there is no standard post size to speak of. nowadays most competent carpenters and/or designers would I think suggest 6x6 s for your posts.

I know that I would, and not to imbed them into concrete but to use one of the typical stand-off post bases designed for this kind of thing. (I know you mentioned brackets)

But perhaps more importantly you need to look at the entire structure and how it is to be built.

Will it have a hard roof or will it be open, what will the structure be used for?

Andy.

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Old 11-23-2011, 09:14 AM   #3
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Post size for an 10x12 freestanding patio cover


You can "get away" with toothpicks if there is no code enforcement in your area. If you are asking for recommendations for sizing, you need to determine the basis of your design first. Since you did not tell us where you live, what code you are designing to (if any), what load will be imposed on the roof, or what the wind conditions are in your area, your question has no context. As Andy indicated, you need to think through the entire design of the patio, focusing specifically on the connections details between the post and the roof. These details are going to drive your decision process.
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Old 11-23-2011, 07:08 PM   #4
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Post size for an 10x12 freestanding patio cover


locally our codes are pretty strict when it comes to sizing beams and the posts they sit on

for decks, pations and such all posts must be as thick as the beam is, most beams are minimum of 4 1/2 inches thick... made up of 3 ply's of 2x material or an single engineered wood beam. so 6x6's get used... i wouldnt play with fire and use a 4x4. ive seen 4x4's snap, not a pretty picture.

the only thing 4x4's are allowed to be used for is hand rail posts,, nothing bearing weight
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Old 11-23-2011, 08:00 PM   #5
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Post size for an 10x12 freestanding patio cover


4x4s just do not look good and give a "spindly" look to the structure. - 6x6s are most preferred unless you are real cheap.

The connection to the slab is important and since you think you need only 4 posts, it is a cheap investment to use a Simpson product designed for the purpose.

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Old 11-23-2011, 08:41 PM   #6
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Post size for an 10x12 freestanding patio cover


You are correct I didn't provide sufficient info. This is for rain cover. I am in Seattle where there is a great deal of wind (and rain), but it is being placed in a well protected small backyard with protection on 3 sides. I plan on covering with 2"x6" cross beams and fiberglass panels. I haven't been able to find good plans for the construction but am planning on using brackets embedded in concrete and to tie in the crossbeams. For visual reasons it needs to be 10 feet high. It sounds like 6" posts are the way to go. Any other suggestions?
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Old 11-23-2011, 09:26 PM   #7
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Post size for an 10x12 freestanding patio cover


I would use 6x6 but so many people bash 4x4 without real cause. 4x4's are still quite strong and can be used in MANY applications, take a look at this article recently in the Professional Deck Builder magazine http://www.deckmagazine.com/abstract/413.html
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Old 11-23-2011, 09:33 PM   #8
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Post size for an 10x12 freestanding patio cover


with something like this the key thing is to check your regions code on such a thing. theres no point in building something if your only going to be made to change it by and inspector. find out first with your local building authority and follow their guidelines. whats good on the west coast isnt alwasy acceptable on the east coast...earthquake zones vs hurricane zones and so on
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Old 01-09-2012, 10:08 PM   #9
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Post size for an 10x12 freestanding patio cover


Thanks for the advice on post size.

I am planning to build a free standing 12' x 12' patio cover about 12' high for a rain protection.

My plan is to erect the 6" x 6" posts and then sandwich them on two sides with 2-2" x 6"s bolted through the posts. I will then install 2"x 6" rafters spaced 12" apart. I want to then cover the rafters with overlapping fiberglass translucent panels. I will erect the posts 4" shorter on one side for water runoff.

I am looking for advice on the stability of the overall structure and specifically about installing the 4 6" x 6" pressure treated posts in concrete since the patio is blue stone tiles.

My plan is to dig 4 corner holes fill them with concrete and embed something like Simpson Strong-Tie brackets in the wet concrete. My problem is that most of their brackets say "Not recommended for non-top-supported installations such as fences". Can anyone provide advice or point me to guidance on support for freestanding patio covers like this.
Thanks in advance.
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Old 01-09-2012, 11:01 PM   #10
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Post size for an 10x12 freestanding patio cover


Look, I think that what we are trying to convey to you is that we can not design this thing for you over the internet, which it seems is what you would like.

I know you are just "looking for advice" on what should be used here or what should be used there or in this situation. But the truth is that this thing really ought to be designed, a set of plans made then take the plans to your building Department and get permits to build.

This accomplishes many good things even though it might cost a few bucks to do.

Andy.
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Old 01-10-2012, 04:36 AM   #11
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Post size for an 10x12 freestanding patio cover


Our professionals here would insist on hiring a structural engineer (or a building designer) to build even a dog house!

Here in Portland you can build anything up to 200 sf without a permit.

4x4s would be plenty strong, and would look better than 6x6s if the top is as light as you propose (it's all about proportions). Personally, I would use 6x6s and make my top a bit more solid-looking. Easiest thing to do is keep your eyes open in the neighborhood for something you like, and copy it, especially if it looks like it's been standing for a few years.

Your design with double 2x6 beams and 2x6 rafters is very standard (and top-supported), and will be perfectly adequate. It will look much better, though, if instead of 2-2x6s slapped on either side of the posts you use a 4x6 on top instead.

You forgot a very important thing in your design: diagonal braces on all four sides to keep the top from racking.
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Old 01-13-2012, 02:40 PM   #12
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Post size for an 10x12 freestanding patio cover


Thanks abracaboom,
Great advice. I hadn't thought of 4"x6" beams on top, your right they would look better.
Do you think 12" x 36" sonotubes would be adequate for the piers?
thanks again.
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Old 01-13-2012, 03:01 PM   #13
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Post size for an 10x12 freestanding patio cover


For the sonotube the 12" should be fine if it is a light as you indicate. For the depth it depends on your frost depth and soil type. Again got any neighbors with decks or such that you could ask?
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Old 01-13-2012, 04:36 PM   #14
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Post size for an 10x12 freestanding patio cover


Essentially zero frost line here in Seattle so 36" should be plenty for lateral support?
Thanks for all your advice.
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Old 01-13-2012, 08:02 PM   #15
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Post size for an 10x12 freestanding patio cover


Quote:
Originally Posted by Cjb4 View Post
Essentially zero frost line here in Seattle so 36" should be plenty for lateral support?
Thanks for all your advice.
The lateral support will be provided by the beams, joists and diagonal braces. You only need the tubes if you want the concrete to stick out above the ground. I would not recommend using the tubes underground; if you do, your foundation is only going to be as firm as the compacted dirt around the tubes (if the dirt around the tubes is not perfectly compacted, your posts are going to wiggle, but if you pour the concrete directly against the undisturbed sides of the holes, without the tubes, your posts won't move at all.

2 foot deep holes is all you need. This is how I do it: I dig a 2-foot hole, the width of the shovel, and widen it a bit at the bottom to form a concrete cylindrical wedge. I place a 4"-6" length of tube on top (once the wet concrete reaches the top of the hole) so that my concrete footing is above the ground, and enbed a metal post base level with the top of the tube. That way the bottom of my posts end up about 6" off the ground, sitting on a nice-looking round concrete footing.

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