Designing a gazebo. 10 x 12. I will be using 8×8 cedar posts. Gaz will have a hip roof on it (5/12). Do I need to double up the 2×12 beams or will a single 2×12 support the rafters without sagging. . I planned on notching the tops of the posts to accept a double 2×12 but the lumber yard shorted me 2-12 footers and 2 10 footers.
Also, I have noticed a lack of available 8×8 post bases. could one weld up a “U” type bracket similar to a simpson?
Replies
Dunno about strength, but it's easier if you double up on the ridge beam, at least. Otherwise you have an asymetrical situatioin the bearing end of your rafters.
Also, for exposed framing the double will look nicer.
(But using 8x8 posts sounds awfully "heavy")
Also, if you have a 10x12 gazebo with a hip roof, where are these beams of which you speak going to go? (Do you have more than 4 supporting posts?)
The client saw a picture of a Gazebo with 8x8s and liked the look. Plus, with the doubled up 2x12 it leaves me alot of meat to run my carriage bolts through. and remember i will be notching 2 sides of the post to accept the converging double beam at the corners. I think the 8s will look good. Wish they made bases more available for them.
I asked the local framing guru at the lumber yeard and he insisted a single 2x12 would sag in a few years. With the weight of a shingle roof and a double layer of decking (so roofing nails wont poke through) I can see his point. Also, a double beam will give my seat cuts more to sit on.
This is the first gazebo I have built and first time to work with LARGE cedar. It will have exposed ceiling so its gonna be a good carpentry job.
Not sure why one would double up the ridge beam. It will only be about 2 feet long. Can you explain that.?
Let me know if I am off track with this. any pointers are appreciated. This lumber was $$$$$$$ and I still need to get more. Luckily I am using frming lumber for the rafters and hips to a boo boo cut is fixable. Now, the cedar..I better be careful!
Just so you know, it is a 10 by 12, 4 posts double beam around the perimeter for my rafters to sit on. 5/12 pitch, double layer of 5/8th plywood.
If you only have 4 posts, how are you going to double the beams by notching both sides? (Make a sketch of how the beams will connect to the posts.)
cedar 2 x 12
First, the information you get of this web site is worth what you payed for it.
Second. More information is would be helpful. How the roof structure to be framed. What kind of loads are envolved. i.e. rafters, ceiling joist, decking, roofing material, ceiling finish material etc.
Is the ceiling going to be flat or pitched/vaulted. If pitched, there will be other structural elements to be considered.
What means are you planning to use to prevent racking. On a free standing structure like this good bracing is critical and is ofter under designed or over looked.
Are you using ceder for the beams to match the cedar columns? If so, cedar is not a particularly good structural material. You may very well need a double 2 x 12 beam. Personally, with the large 8 x 8 columns, I think that a double beam would look better even if a single would suffice.
here is a sketch. Ceiling will be vaulted. Exposed framing and stained underneath. Thats why a double layer of 5/8th plywood. I will use pine T1-11 siding for the visible....and yes my math was off on the sketch..should be 5 inches and 3 inches..the 8x8 are actually 8". I am wanting my beam to be 1/4 inch outside the post for esthetics
..and yes I will be using a 2x12 with a scrolled design for my brackets to avoid racking..probably 2 feet long with a lag screw on top and bottom and a few discreet screws as well.
Ok, so you're not planning to put the boards on opposite sides, but instead you're going to sister them.
Are you going to use any rafter ties?
yes, if they fit unseen on the outside. If they show I may use an 8 inch timber screw straight down through the top of the rafter. It get crazy windy here (40+ mph not unusual).
No, by "rafter ties" I mean
No, by "rafter ties" I mean ceiling joists or collar ties -- to keep the rafters from spreading.
No rafter ties are necessary if it is a hip roof as he says it is.
I don't understand the dbl 5/8 plywood....
dbl ply
He's laying T-111 face down on top of the rafters, then another layer of 5/8's sheeting. Good looking from below, and thick enough the roofing nails won't be driven through that first layer.
gazebo
We still don't know what kind of loads or the types of materials we are dealing wirh so it is impossible to offer any advise as to the beam requirements.
However since you will have a pitched ceiling with no ceiling joist/ties, here are a couple of thoughts
Use double 2 x 12's not sistered. Notch columns on all sides to receive 2 x 12 beams. On top of the beams secure a 2x? flat to act as lateral beam to offset the lateral/thrust forces created by the lack of ceiling joist/ ties.
Again, since we don't know the loads etc, can't suggest any sizes.
What do you mean "double, not
What do you mean "double, not sistered", and "notch columns on all sides"? There are only 4 columns in the design.
I think what he is suggesting is straddle both sides of each post, but also notching them to add support. Then adding a 2x either on top or sandwiched between the two beams. Either way though it increases my beam width to 8". Seat cut for my rafters would be screwed up.
Yeah, that is what I mean. It would be like using wide top/tie plate. It could be anywhere from 8" wide or wider as required. As too the seat cut, it does not have to be the width of the wall or whatever is supporting it. Im doing a 9' x 15 porch addition with a arched/pitched ceiling. I have a 1-3/4 x 11-1/2 LVL for a top plate to resist the lateral loads. It will have thick heavy tile clay tile shingle. The rafter seat cut will be the same as they would have been on a 3-1/2 wall. It will required a slightly different trim out than normal.
As to loads I keep bringing up. Since he is using timber columns, I thought he might be using timber roof framing. Also there are shingles and then there are SHINGLES. Also as he was considering using only a single 2 x 12 cedar beam, I felt that that information was critical.
I'm done.
thanks for all the input. What really sucks is that I am eager to get going on this. Client said that they will be out of town for a whole week. That would mean I have free reign of the backyard with music and no interuption...however..the Lumber yard shorted me 2 -12 footers and 2 -10 footers (which is the point of the original post..thought I might be able to make one 2x12 work), so I have to drive to Dallas tomorrow and get what I need. And..I have to fabricate my own 8x8 base. ..AND my wife informd me I have to drive my daughter to Lubbock wed...so what was goingto be a glorious, productive week has turned into a clust f****
Cuta. I'm over in Ft. Worth. Sorry I couldn't be more help. I know what you mean by having the backyard all to yourself.
Are you taking your daughter out to Tech?
yes a debate camp...you can help....bring me 2 12 footers, 2 10 footers and one 8 footer. : )
I considered that for a moment, but quickley discounted it. I try to stay out of all that traffic over in big "D" :>)
The best to your daughter in her debate camp. Y'all be careful; hear.
I was kidding of course..thanks for the help
But you can't put the beams on both sides of the post. Won't work, not on corner posts.
No need for the seat cut to be the full width of the built-up beam, though, if you did manage to do something like this.
Yes you can. If you notch the inside beams to sit one on top of the other. Also the notching of the beam is not weaking their ability to support any required bending loads and unless you are dealing with extreme loading, shear normally would not be a factor.
You'd have to take away half the meat in both pieces. And do it cleanly and accurately enough to look good.
Some very good points. I also think an Environmental Impact Statement shoud be provided. What about the sea mammals? Are there any salomanders which might be impacted. Perhaps some of this damage could be addressed by adding elevated nesting boxes on the structure. ....