Porch Beam size and placement question

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Old 11-07-05, 11:16 AM
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Porch Beam size and placement question

Rebuilding a front porch. Have 6x6 posts going up to the roof and want to attach the beam to the posts. The joist span is 8 feet(from house ledger to posts) and am using 2x6 at 16" o/c. There are 6 posts altogether, each spaced 5'9" apart. We are planning on using a 2x10 attached to the inside face of the posts with 5" lag screws as a drop beam for the joist supports. Is this normally considered sufficient or do you have to "sandwich" two boards around a post when you aren't notching into them? Local building department is very very hard to get ahold of or get straight answers from. They are small town volunteers.

Thanks....Tom
 
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Old 11-07-05, 02:59 PM
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Tom,

There's a LOT more to it than what you have told us so far.

What snow load do you have to meet? Wind load? Siesmic zone? What kind of wood is involved?

Generally, you don't lag bolt the beam to the face of the posts -- the beam rests ON TOP of the post (That's a lot stronger). And the beam is generally the same width as the posts that support it. (You want to use a 6X beam if the posts are 6X6's) Attachment from the post to beam usually uses a Simpson BC of the appropriate size to keep it all together.
 
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Old 11-07-05, 04:01 PM
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Thanks for responding.

Snow load shouldn't be an issue as it's a covered porch and the 6x6 posts(6 of them spaced 5'9" apart o/c) run straight from the concrete footings/piers right up to the header that supports the roof. That is in place now. Because the beam can't sit on top of the posts since the posts run up to and support the roof the only options are to notch the posts or to attach the beam to the post with lag bolts as I've seen pictured many times in books. Usually the pictures will show the beam sandwiched on both sides of the post (like a 2x? on each side of the post with a single carriage bolt holding them).
Wind is not a problem nor is their seismic activity. I am using pressure treated wood.

Thanks.
 
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Old 11-07-05, 05:15 PM
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Tom,

Snow load IS an issue if you live in an area that gets, or can get snow. When it snows, the snow lands and sits on the roof. The posts have to be able to support that extra weight.

Wind loads are figured in for the same reason. Both are arrived at by the historical weather data of the area in which you reside. And I'm not aware of any place where the wind doesn't blow fairly hard at least once in a while.
 
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Old 11-07-05, 08:30 PM
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The 6x6 posts on conc. footings/piers are replacing similar 6x6 posts which used to run into the ground and were cemented in place below the frost line. Support was never an issue on the existing porch in over 20 years. My question centers around the beam construction and whether or not a single 2x10 drop beam carriage bolted (2-5"x1/2" bolts per post) onto the posts will meet IRC code.

Thanks again...Tom
 
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Old 12-08-05, 10:05 AM
jedi105
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Porch roof column placement

Hello all. I'm new to this (Homeownership and home improvements) and would like some opinions or suggestions. Here's where I'm at.

I had a new roof installed recently. At the same time, I had an awning built into the roof line that covers a large cement and brick porch. The awning was built with a rafter for each roof rafter. The roof was ripped open to allow the awning rafters to be bolted to the roof rafters. The awning deck is 3/4 roofing grade plywood. The rafters are notched on the ends and sitting on 2 2x6's nailed together. It is covered with architectural shingles and a small amount of vinyl siding. The thing is probably very heavy. Currently, it is sitting on 4 Home Depot special turned 4x4 posts. The 2 end posts are attached via brackets to the cement slab of the porch. The 2 center posts are just sitting on aluminum end caps. This post configuration was a last minute thing to get rid of the ugly 2x4's nailed together to hold it up. The posts were not the contractors responsibility as the agreement was to just support it. The contractor feels the awning only needs 2 posts for support. The carpenters who built it feel there should be 4. My problem is, the posts really look terrible. They take away from the whole project. I live in New York so heavy snow is possible. Ice is also possible. The awning is approx 20 feet long and extends approx 7 feet from the edge of the house. My questions are

1. How many posts and where to place them. Will 2 posts placed about 2.5 feet from the side of the awning be good enough?

2. Will adding a 2x10 beam to the inside of the fascia (atached to the 2 2x6's) add enough support to make the whole thing rigid enough to support all the weight and not sag in the center.

Please remember, I'm new to this stuff so please be patient and please keep the criticism to a minimum. I cannot go back to the contractor as I have already accepted it and paid for it. I know I'm screwed but cest la vie. Call it lessons learned.

I can send pictures if you want to look for yourself.
 
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Old 12-08-05, 06:02 PM
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tomzpc,

If you are in an area where a 'frost line' is involved, then I will almost guaratee you that snow load is an issue as well. Bolting the beam to the posts isn't going to cut it, at least not per the UBC. BUT, you have to build according to the IRC. Things may different there. Go ask you local bldg. dept., and WAIT for an answer. If that's slow in coming, MAKE NOISE!! (The sqeeky wheel IS the one that gets the grease!)

jedi105,

The carpenters are right, and FIRE the @#($^ contractor!!! From what I'm reading between the lines here, he built your cover without a building permit. That may or may not be an issue, depending on where you're at and what the local bldg. dept. requires. Does he have Worker's Comp. Insurance on his employees?? (If one of them gets injured on the job, WHO PAYS??)

"The carpenters who built it..." That tells me that he subbed it out. Are these carpenters listed on the PRIME contractor's liability ins. policy as additional insureds??? (Does the prime even have liability ins.??)

That beam he installed ISN'T going to support the roof with only 2 posts. It needs at least 4. If the posts that the carpenters installed are ugly, go back to the big orange box and order 2 more and replace them with those. Use the proper anchors to secure the posts to the slab.
 
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Old 12-09-05, 04:52 AM
jedi105
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Thanks for the response. When I got home, I called my brother in law who is a building inspector. He came out to look at the work and according to him, most of the work was done up to and exceeding code. Bolting the rafters of the awning to the rafters of the roof is acceptable and they exceeded the code by placing a rafter for the awning to every rafter of the house. Minimum code was every other rafter. The 2X6 beams nailed together are sufficient. The math wiz he is feels the awning will easily support any extra load with the 4 posts as described. The only thing he wanted to do better was the size of the posts. He wants me to replace them with 6X6 posts instead of the 4x4's that were installed. He also wants me to anchor the posts to the beam better. The anchorages to the slab are up to code. A building permit was not required because it was replacing an existing structure and it did not extend from the house more than a certain distance. I want to say 17 feet but I don't remember what he said. The contractor was insured and is a member of the BBB where I live which I checked out before authorizing the work. According to the BBB, there have been only 4 complaints issued against them in the last 5 years and they were all billing complaints. Seems he does tend to go over estimates quite often. His estimate for me was dead on. And his carpenter crew is his companies crew but it seems the contractor guy I spoke to is just the salesman and really does not know all the ins and outs of carpentry. He comes in and gets the specifics of what the customer wants to do and then he later has his people come out to figure how much materials they will need and the best way to build whatever it is they are doing. They tend to disagree a lot since he is a salesman he likes to low ball everything to get the sale. So things are on the up and up I guess. I just dont like the darn posts. The way my porch is built (Center slab of thick concrete surrounded by a brick face) and the size of the awning that was installed (it extends to the edge of the concrete but not into the brick) I am stuck with the placement of the posts. Unfortunately it takes away about a half a foot around the edge of the porch. It wouldn't be so bad but my porch is also 3 to 3 1/3 feet tall so I have to have railings around it. I think this is where the problem with the aestethics is. The posts do not match the railing that is up. I guess I could replace the railing and tie the posts into a new railing system but again, that means I will loose 1/2 foot around the perimeter of the porch. This makes it feel a little claustrophobic.
 
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