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I have a small roof going over a concrete porch. The porch has a full footing under it which will carry the load of the support posts. The new roof structure will be a gable tied into the existing hip roof. The new roof will extend 7 feet out and is 10 feet wide. I just had 2 12″x12″ x 36″ brick piers built on each side of the slab which are hollow in the middle. The brick piers will have 14″x14″ limestone caps on them. My question is…..what is the best way to install the support posts that will hold up the roof? Should they run down through the center of the brick piers and sit on the slab, or should I fill the center of the piers with concrete and set the support post on top of the limestone caps? Also, are 2 2×4’s nailed together sufficient for the support posts that will hold up the roof? Thanks in advance for your help.
Ed
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2-2x4's will be pleanty strong if they are only 5" high, not strong enough to resist buckling if the roof is 40' above the brick. Somewhere inbetween- you'll need to have somebody look at it.
We don't know the snow load in your area, how long the columns are, what the roof pitch is (needed to snow load calculations), what the roof structure will weigh, what the roofing material will weigh, how you intend to prevent racking of these two columns, etc.
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Ryan,
If I go off the slab the posts will be 7 1/2 feet. Off the top of the brick pier the posts will be 4 1/2 feet. The roof will have a 4/12 pitch with 2x8 rafters and 30 year asphalt shingles. I live in the Chicago area so we do see a good bit of snow.
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Ed, fill the brick piers, and place the post on the cap, the masonry will last alot longer than the post, and you don't want someone to have to rip out the piers to replace the posts. According to our codes here in Mn. your roof needs to support 55# /sq. ft. that's 40# live load (snow) and 15# dead load (roof structure/roofing). This means each of your posts needs to support 960#. 2-2x4 should do the job at 4-1/2'
. How are you going to attach the posts to the pier?
Are you going to wrap the post with 1x material?
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Steve,
The posts will be wrapped with 1x material. One idea I had for attaching the posts was to drill a hole through the center of the caps and run a piece of rebar or a piece of allthread through it to keep it from kicking out.
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I'll go with Steve. If only 4-1/2' columns, I think doubled 2x4's would work. But, why not use 4x4.s instead. They're square while two 2x4's will be 3-1/2" x 3", a rectangle.
A piece of rod grouted into your posts sounds like a good way to keep the bottoms secure.
Once the roof is sheathed, this thing will be real ridged but I still like to try to do something to make sure the free end of the roof can't move back and forth and rack your posts. (does this make sense?)
I like to run my posts all the way up to the roof line.
*If it were me, I'd use a steel column set on the slab, with concrete poured around it in the pier. Then I'd trim around it with wood from the limestone cap to the roof structure above.
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I have a small roof going over a concrete porch. The porch has a full footing under it which will carry the load of the support posts. The new roof structure will be a gable tied into the existing hip roof. The new roof will extend 7 feet out and is 10 feet wide. I just had 2 12"x12" x 36" brick piers built on each side of the slab which are hollow in the middle. The brick piers will have 14"x14" limestone caps on them. My question is.....what is the best way to install the support posts that will hold up the roof? Should they run down through the center of the brick piers and sit on the slab, or should I fill the center of the piers with concrete and set the support post on top of the limestone caps? Also, are 2 2x4's nailed together sufficient for the support posts that will hold up the roof? Thanks in advance for your help.
Ed