Looks like you've got it. The rim joists can line up with the outside edge of the blocks. The columns can just fall where ever they fall, it is not important that they be directly above the piers, its nice if they do, but the foundation is more important. If the columns fall vary far from the piers, then increase the rim joist to 2x10, if they are within a foot, a 2x8 is fine.
At the corners, you will need two blocks in an L shape.
Well, it's easy to talk and draw pictures ;-) Now we'll see how I can go about "doing" some of this. If I use -- which I now hope to -- the existing footers, then the columns will be within a few inches of the footer, so the columns will be more or less directly on the blocks. To get that L-shape (2 blocks) at the corners I guess I need to pour a bigger pad -- 28 x 20 or so -- correct? At those corners I will not be centered too well over the footer, but again the new framing will do a better job of distributing the load.
On my original plans (again, the builder did not follow), it shows 12x12 brick for the piers. I suppose I could use a colored brick which might be more appealing, but then I need to learn more about mortaring brick together.
Do you think I can do this one side at a time? Lift up my north side -- 1 center column and the corner (pad, pier, framing), then south -- 2 center columns and 1 corner, and then the east 4 center columns. I'm just concerned about my ability to support the entire U-shaped porch roof while doing all this -- and knowing it's going to take me many weeks, and I'm also coming into winter and freezing temps. Will lifting parts of the roof cause any damage there (vs all at the same time)?
New drawing with L- corner
Looking at that , it sure would be nice to pour another 6" footer or enlarge the 6" footer that is there on those corners. I have only 2 corners. Something to contemplate I guess.
Also, I drew this one with double 8" joists (ledger to rim) and 2x6" blocking (from joist to joist). I don't know if that 2x6 will be sufficient or not. I guess I will run the costs and see if it's even worth the savings.
Should I even consider re-using some of my non treated lumber? Most of my existing joists are in good shape -- some of my rim joists also. If not, I guess I'm going to have a pile of 6' 2x8s and a few 10' 2x10s for some other project.
I did mine a section at a time. However, if the roof of the porch is cantilevered off the house, you can't jack it up at all. The fact that your columns did not sag with the foundation causes me to be concerned about that.
My porch roof is independent of the roof structure of the house, which is typical of most houses. But if you have a shallow pitched roof, then it is possible that your roof rafters extend all the way out over the porch, that is its the same rafter for the house, just longer so that it covers the porch as well.
If yours is the much more typical attached porch roof, then it is held in place very well, but it should tolerate jacking up an inch or so to slip the porch decking under the columns.
The corner pads can be L shaped instead of one large square pad, thats between you and your local codes. You may or may not need another footer. If you have a post hole digger, it probably wouldn't hurt to add one, but I don't think it is necessary. You would have to check with local code enforcement on that. Just be aware that if you go to them, they might find other issues that will have to be addressed, even if these are issues that arised due to a change in the codes.
I would not reuse any old wood from the project, especially untreated, for the framing. If it deteriorates in the future, then look at all the work you have to do over. If any of the T&G is in good shape and you want to reuse it, I'd say OK as long as it is not used directly under a column. It is best reused where it can easily be replaced.
when I did my porch, I too was tempted to reuse some of the framing because it looked so good, almost as good as new, but I just do not want to do this project over again, ever.
I have not seen PT T&G so I guess that you will paint it and the old stuff was painted as well. Whether new or used, I would at least prime all six sides with an oil based primer before installing. I would also top coat all six sides but I know that many would advise against that because that will keep the wood from "breathing". To me, if the wood is dry and stable, I don't see any benefit to allowing the wood to "breath".
BTW, while you have the porch off, be sure to look at the foundation vents, if you have a crawl space. If they need any work, this would be an opportune time to fix them and upgrade if you wish. I know on mine, critters had destroyed the screens in them in order to get access to the crawl space in winter. I replaced all of them and I covered them with heavy duty hardware cloth to keep the unwelcome critters out.
While your at it, look at the grading. Sometimes contractors don't grade properly under the porch and then water can be held against the foundation walls. I know this is additional work but if regrading is needed, you should do it, it will save you from problems later.
In the original plans I don't see any info on the porch roof. The 2 corners seem to be sitting the most solid -- maybe they are supporting a lot of the load. The south side is where 2 columns are dangling about 1/4" to 1/2". Otherwise, the columns are resting partly on their piers. But below grade, and by a few inches in some cases.
I figured a rectangular pad would just be easier to frame up. My footer in those corners is going to be directly below only one of the blocks (piers). It's poured right at the corner, so only one block will be overhead. The other block can rest on a pad, but that pad will not be over the footer. I can try to tie it in with rebar.
Full basement here -- and from just a glance, the walls seem to be OK. I do need to look at how they attached the ledger. I suspect just wood screws. I know it is just up against the siding. No flashing, etc. My back deck is even more amusing. They just screwed joist hangers into the siding. That's another day.
Menards here has 12' and 8' PT 4" t&g flooring.
rim joists will be doubled -- not shown
between each double joist will be 3 evenly spaced single 2x8s that run parallel to house - not shown. The flooring will be nailed to those.
It looks like all framing done with 2x8s will run me about $600. I could save maybe $60 or so by using 2x6 blocking, but don't see that it's worth it.
Hopefully I can salvage 1/2 - 2/3rds of my t&g flooring, and then lay down the new PT flooring. On my old ones.. I'll do a quick sand, and then prime & paint all sides (6) before assembly -- put a coat on the tongue during assembly, and then topcoat all of it. Since I can run the flooring perpendicular to the house -- each board will be 6' long (some sorter at the corners.. and two long pieces at the corner diagonal). Having each 6' will make future repairs very easy -- compared to what I have now -- very long lengths with random damage which makes any partial repair an eye sore.
Onto lifting up the roof a bit -- and trying to repair the pads. Cutting off the columns will be the point of no return.
What size of rebar - 3/8" or 1/2" ?
I'm thinking the smaller will be easier to bend 90 deg, so go with that?
What sort of hammer drill will I need to drill the holes in the footers? There is a 7A $49 refurbished Bosch 1191. Will that do? I'll likely do 2 or 3 footers at a time - and 4 holes in each. I believe it was suggested to drill them 12" deep. Any suggestions on bits? If I used 3/8" rebar, then I guess I'll need a 1/2" hole.
Another thought -- will the rebar add significant structural support? At least enough to justify all the work? I guess it will tie the pad to the footer, but if there is significant offcenter force, will the rebar really counteract it? By framing (as shown in the drawings) atop the block, pad, and footers and then putting the porch column atop the framing, that is what seems to be distributing the load.
Maybe I can just pour a new pad without rebar -- then add the blocks, cap, and rim joists?
Also if I ever need to redo those pads, etc, the rebar is going to make that much harder.
Would appreciate any thoughts.
The rebar was just a suggestion on my part. I hope someone else will weight in on this one. It may not be required, but I can't help but think that if rebar was used in the first place, you might not be having to pour new pads now.
If you have a regular drill, you might try it with just the masonry drill bit, I have done that but it is much slower than a hammer drill. I was only drilling 1/4" holes about 3" deep so a hammer drill was not necessary. Its just a question of the amount of time you have. I also did not have a carbide tipped drill bit, just a cheapy. I'd spend more money on the drill bit and get the cheaper hammer drill if necessary.