If you sort by date -- oldest to newest, that takes you on a journey around the porch, and then back around again. There is a shot of the north side, then 2 shots each of the columns, then a shot of the east side, and the columns there, and finally a shot of the south side and the columns there. Then I come back around with a few shots of the topside of the porch.
In a few cases, the concrete pads "look" solid -- but I'm doubtful based on what I see with all the others. In several cases you will see the smaller diameter concrete pillar extending up through that "top pad".
It looks like you have two issues besides the rot, the concrete piers are deteriorating and settling. How much clearance from the bottom of the porch frame to the ground? What's the total height of the floor of the porch from the ground?
Depending on your clearances above, you should consider building concrete block piers up to the bottom of the porch frame. Rest a double 2x10 treated on top to form the perimeter. Then frame between the perimeter and the ledger. Be sure to use some ledger screws in those ledger boards so they can't pull away from the house.
The perimeter should be just below the columns. You will have to support the roof with some 2x4's, jack it up a couple of inches for clearance. After the framing, lay down the porch floor, then set the columns down on the porch floor. This means that you will cut the columns shorter as they won't be going to the ground anymore.
Ideally there should be one pier under each column, but that is not always necessary. Afterwards, if you want to dress it up, you can brick or stone face the block piers and put some lattice between them.
How do I build the concrete block piers? As I have mentioned and is visible in the photos I seem to have 6" concrete piers that run deeper into the ground and then atop that they poured a 5" thick or so pier that is 12" in diameter. That really should have ran to below frost line, instead of trying to stack it atop the 6" pier. If the whole pillar was 12" in dia. down to frost line that would be better. The columns are not resting squarely above the 6" piers and so the 12" "pad" is deteriorating and tipping or in some cases the 6" piers seems to have sunk.
What you describe sounds like the original plans. They also show the joists running parallel to the house, and then the t&g flooring running perpendicular to the house -- which makes more sense.
Doing all of that that is a complete rebuild. I might be able to salvage some of the decking, but since all the framing is not treated, I'd probably replace it as well -- and fix the house ledger also.
This is a lot more work/cost than I was hoping.
Re: the concrete block piers -- can you better describe how those are built? Do I need to pour concrete pillars below frost line?
Thanks so much,
I am in the process of rebuilding my porch, I am done with the deck so it will be hard to show how I did it, but is sounds like mine is done the way yours was supposed to be done according to the blueprints you describe. All I have left to do is the porch railing system. My porch deck is about 3 feet from the ground. Its too dark to take any pics tonight.
If I read the plans right, it's as you describe - with the framing sitting on concrete pillars that are several feet in the ground (below frost line). Then the framing is atop the pillars -- and in fact, the joists hang in between 2x8s that run from the house ledger to the pair of 2x10s around the perimeter. So the joists run parallel to the house and are supported by 2x8s that run perpendicular to the house and are hung on the ledger and the pair of 2x10s atop the pillars. The flooring than sits atop the joists, so it then is running perpendicular to the house -- which makes sense. Most flooring I see comes in 8' or 12' lengths. A 12' length cut in half is just the right length for my porch.
As mine exists -- the joists run from the ledger to a 2x10 that was only screwed to the 6x6 columns. Clearly they saw that as a problem, and screwed a 2x6 underneath that 2x10 so the 2x10 rested directly atop that 2x6 that then ran down to the concrete pier. The problem is , my concrete piers are faux. There seems to be a 6" diameter pier, but it's not directly beneath the column. So they poured another 12" "pad" -- that sits atop the 6" pier. But even then, the column is not centered on that pad, so in some cases, the column is offset from the center, so the pad is tipping, and in some cases all of it must have settled because the column is "dangling".
So clearly the right way to do this is to rip up all the t&g flooring -- most of what is rotted I've removed already. So I guess I can remove the rest, maybe salvage 50%, then tear out the framing, and decide if any of that is worth reusing -- none of it is treated. I suppose with a good floor above it, treated is not critical -- and with the floor running in the proper orientation, it will be much easier to pull out a few boards and fix any future problems.
My biggest challenge -- other than the amount of effort and cost -- is going to be to hold up my roof while I tear this out, and somehow re pour the piers. I was thinking maybe I could rest the new piers directly on the ground -- but that makes no real sense to me for a covered porch. A shed maybe, but the roof to my house -- I guess I better pour an 8" pier down to 3' -- although maybe a 6" pier would be enough if I pour it where it needs to be! Then I build my frame atop the piers.. and finally cut my existing columns and rest those on the floor (which is directly atop the framing and piers). Nothing like starting over.
What I need the most help with is the piers - how can I do that? There is going to be that old 6" pier in the way. I guess I can dig by hand around it.. drop in an 8" casing and then backfill around that? In otherwords, the old 6" will be inside the new 8"? Unless I find the 6" only goes down a foot or two -- in which case, I yell a bit louder and do my best to get it entirely out of there.
Now -- all this said -- should I even consider some sort of retrofit to what is already in place? Get rid of the porch entirely and just pour a concrete porch?
How do I support my porch roof while all this is taking place.. and given it's going to take me a good bit to do the work?
Thanks for putting up with me. Kind Regards, Kevin
I took some pictures this morning, keep in mind that this is still a work in progress and that I live out in the country so I don't have to be concerned with what any neighborhood association thinks about the mess. I have been rebuilding the porch over several years as sections needed. The front and back and the corners have all been done, this is the south side porch. I still have railings to do and then the green house.
As to the style and materials, that is dictated by the style of the house. My porch is done much like many outdoor decks are done and it fits with a log house. This may not quite work with your home, the decking of T&G may be better suited, it would not work for me. Also, if I was doing the whole thing at once, I would probably frame it different and run 5/4 x6 PT deck boards parallel to the house instead of 2x6 PT perpendicular.
I think some of your framing is overkill as your span is not that great. If your deck were 14' wide, then you would need the 2x10 joists, but in your case 2x6 is adequate. You still need a double 2x10 around the perimeter.
I don't have to worry about a frost line so my footings are not all that deep. The footing have to meet your local code. Here are two pictures.
The first picture shows the column directly above the pier as would be ideal. But the piers and the columns do not share the same spacing as you can see in the second picture. Originally the rim joists (perimeter) were a double 2x6 on top of a 2x6 plate, all untreated, and it began to sag pretty badly. I did away with the plate, went to a double 2x10 PT that I notched down to 5.5". I wanted to drop the deck by the 1.5" that came with removing the plate so that the deck would slope down away from the house. The house had settled (log houses are very heavy and settle a lot).
I don't think the rim joists will sag now as the roof isn't all that heavy. I did all the rest of the framing with 2x6 PT. The deck is very stiff, no bounce. The original framing with 2x6's as the rim joists was a bit bouncy. The porch is only about 7.5' wide. The supports that go from the ledger to the rim joists are only 80"' so the 2x6's are plenty stiff enough. They are 8' apart so I didn't have to cut the joists. I doubled them as well, but for even spacing, I had to separate the double part by about 6". I braced between them. The joists are 20" apart.
This last photo shows how I supported the roof. This is just simulated, I actually used a 2x4 on each side of each column. I used another 2x4 and a floor jack to jack up the roof before setting the supports, reversed this procedure to remove them. In my case the columns support 6x8 logs that the roof rafters sit on. You will need to determine the best places to put your supports.
I notched the supports on both ends so they would not be able to kick out on me. The bottom notch actually sat on the inside edge of the cap block you see there and the two stakes were to keep the cap block from moving. I would have had to jack up the roof again to show this, I hope you understand my explanation. BTW, as an added measure, I put one 16d nail through the prop and into the column at the top to keep the props from kicking sideways as well. as you can see, my columns are 6x6 cedar as well.
The distance from my house to the rim joist will be about 6'. Do you suppose I can run 2x6 joists from ledger to rim joist (perpendicular to house) at 8' intervals, and then put 2x6x8' blocking (parallel to house) between those 2x6 joists? I'm just trying to simplify the construction with those 8' long blocking pieces. I guess I could put my joists at 6' spacing and then use 6' blocking (a 12' cut in half).
I'll have a double 2x8 or 2x10 at the rim joists. My plans show a 2x8, but my spans from concrete pier to pier are 8.2 to 10 feet, so maybe a 2x10 would be better.
I'm still struggling with how best to lift and support the roof. Maybe I can do this one side at a time (north, east, south).
Is there some rule of thumb that says to use a width of board in inches the same as it's span? In other words, use a 2x6 for 6' span, a 2x8 for 8' span, a 2x10 for 10' span and so on? Is there any truth in that?
If you build a pier directly under each column, then a double 2x8 should be plenty sufficient. Along my porch at the front of the house, my piers and columns line up so I used double 2x8 there except for the section the front steps are attached to, I used a double 2x10 there. I used double 2x10 on the side porch because they didn't line up.
I so no reason why you can't use 2x6 for everything else but I am not a structural engineer. There are tables for spans in various books, but dimension is not the only factor. Some woods can span further than others. I believe there is even a difference between white pine and yellow pine. You can certainly shorten the span for the blocking if you are not comfortable. You could also use 2x8 from the ledger to the rim if you are not doubling these. I think one reason my deck was so bouncy before was that only one 2x6 went from the ledger to the rim, I used two.
I am using 2x6 and my porch is very stiff, but I am using joist hangers and I think that adds to the stiffness and I am using 3.5" coated SS deck screws to join the joists instead of nails. again, the screws help prevent any flexing. I also use those special ledger screws, one every 4' seems to be adequate, that in addition to the two 16d nails every 2'. The screws prevent the deck from being pulled away from the house, a common cause of deck failure.
BTW, for span to width, I think its more than 1:1. The Habitat Houses that I have worked on spanned 12' from rim to center and they used 2x8. My house has a 14' span from rim to center and uses 2x10. A porch doesn't usually see the floor load that the floors inside the house see.
I believe the original plans had the piers at the columns with all 2x8 framing. The rim joist was double, the joists triple, and the blocking single. The joists I believe were only at the piers, which makes those pretty far apart, 8 to 10 feet. It seems like it would be easy enough to run a single joist every 6' and then block between them.
I'm going to have to see about lifting the roof and see what I can do with the piers I have there already. It might be a real bear to pour new ones directly below the columns, unless the ones there are easy to get out or work around. From what I can see it looks like the poured 6" piers and then try to get away with a 12" pad atop that. Unfortunately, some settled, and since the columns were not directly overhead, some of the pads tipped.
How do I pour a pier? 8" diameter? any rebar? I saw a pole barn built, where they just poured a 10" dia. or so pad a few inches thick down below frost line, and then they just sat the a pole atop that.
Frost line here is 2' -- so I've read the pier depth should be 3'
The part you pour down to the frost line and below is the footing. The concrete blocks that you stack up to the porch are the piers. You need to check with your local code enforcement for the minimum dimensions of the footing. If the footing only need to be 6" diameter, then you will need to top it with a pad to support the concrete blocks. I don't know if you would be allowed to reuse the footings and just pour a new pad on top, not sure you would want to even if you could.
There is a benefit to following the blueprints, no reengineering required. I would suggest that you do that. What works for me is different because I have exceeded what was originally done, and it was done by the blueprints. It just wasn't done well and I don't think the original plans were really sufficient.