billconner
Well-known member
I think I know the answer but I guess hoping someone can convince me I'm wrong.
Wrap around porch about 6 1/2 ft deep. Ledger on top of foundation wall, and 6x6 pt posts along perimeter - about 6 1/2" o.c.
I want to put a 13 x 6 1/2 foot extension on middle of long - 26 ft - side, basically 2 bays by 1 bay deep.
So, do I dare support half of extension on existing 6x6 posts, not knowing how deep or what they sit on? I'd like to just stiffen edge beam and treat it like a ledger for extension, with three new posts (probably concrete in so you've above grade with post anchors) and a beam. What are odds existing piers will support another 2000 to 2500 pounds (center pier of 3 with max live load and snow load). I'd say it was medium to coarse sand with just a trace of salt - so probably good for 3000 to 4000 psf minimum.
I can put in two more piers a foot or so from existing porch and a beam so they are taking the floor load, but roof load would still be on existing posts atop existing piers.
Trying to figure out if I can/should just do 12" sonotube or put in a 18 to 24" footing and do 8" tube on it. And at our age - doubt we're in this house more 10 years - I could just do a footing - even gravel - and PT 6x6s in the ground. Excellent draining at top of a long sandy slope. Might wrap them with post saver, and/or order better posts - UC4B - with lots more chemical in it.
But primary question remains about adding load to existing.
Wrap around porch about 6 1/2 ft deep. Ledger on top of foundation wall, and 6x6 pt posts along perimeter - about 6 1/2" o.c.
I want to put a 13 x 6 1/2 foot extension on middle of long - 26 ft - side, basically 2 bays by 1 bay deep.
So, do I dare support half of extension on existing 6x6 posts, not knowing how deep or what they sit on? I'd like to just stiffen edge beam and treat it like a ledger for extension, with three new posts (probably concrete in so you've above grade with post anchors) and a beam. What are odds existing piers will support another 2000 to 2500 pounds (center pier of 3 with max live load and snow load). I'd say it was medium to coarse sand with just a trace of salt - so probably good for 3000 to 4000 psf minimum.
I can put in two more piers a foot or so from existing porch and a beam so they are taking the floor load, but roof load would still be on existing posts atop existing piers.
Trying to figure out if I can/should just do 12" sonotube or put in a 18 to 24" footing and do 8" tube on it. And at our age - doubt we're in this house more 10 years - I could just do a footing - even gravel - and PT 6x6s in the ground. Excellent draining at top of a long sandy slope. Might wrap them with post saver, and/or order better posts - UC4B - with lots more chemical in it.
But primary question remains about adding load to existing.