Home>Discussions>EXTERIORS>Pouring New Piers Around Existing Ones
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Re: Pouring New Piers Around Existing Ones

Ok, so looking ahead.

Do I mortar/glue the blocks to the pad, and the "cap" to the blocks? What about the 6x6 column to the floor?

keith3267
Re: Pouring New Piers Around Existing Ones

You morter the block to the pad, the pad needs to be larger than the block. Footer, pad, block, cap. The 6x6 column can just sit on the deck but you might want to set it on a cleat.

Re: Pouring New Piers Around Existing Ones

The original arch drawings got me thinking -- they spec a 24"x24"x12" footer -- then a 12" x 12" pier up to grade -- then they mortared bricks to form a 12x12 pier to framing height. Do they make 12" blocks and caps? I don't see any. The 16" blocks are what is causing me to pour another pad atop my footer. Just trying to simplify if possible.

Re: Pouring New Piers Around Existing Ones
coloradotrout wrote:

The original arch drawings got me thinking -- they spec a 24"x24"x12" footer -- then a 12" x 12" pier up to grade -- then they mortared bricks to form a 12x12 pier to framing height. Do they make 12" blocks and caps? I don't see any. The 16" blocks are what is causing me to pour another pad atop my footer. Just trying to simplify if possible.

Keith -- any thoughts on that? I know we have been discussing the footer (12" dia tube or direct hole fill), then a pad, then the blocks, and the cap block. That 16" block is not really needed, as a 12x12 would be adequate. I guess I could mortar up some bricks right atop the 12" diam footer/pier. Or maybe I just need to frame up the "pad" as part of my footer/pier on the initial pour.

keith3267
Re: Pouring New Piers Around Existing Ones

If you can find a 12" block, I suppose it would be OK. The 16" block has 1" thick walls, if the 12" block also has 1" think walls, then only the cavity will be smaller.

I don't see why you don't just do it with 16" blocks, its just not that hard. You bore or dig your footing down to the proper depth, then excavate down 4 to 6" around the hole and put in a 2x4 or 2x6 frame slightly larger than the block with the top at grade level over the hole. Add a little rebar and then fill with concrete. Make a larger pad on the corners, L shaped if you want.

Re: Pouring New Piers Around Existing Ones
Re: Pouring New Piers Around Existing Ones
keith3267 wrote:

I don't see why you don't just do it with 16" blocks, its just not that hard. You bore or dig your footing down to the proper depth, then excavate down 4 to 6" around the hole and put in a 2x4 or 2x6 frame slightly larger than the block with the top at grade level over the hole. Add a little rebar and then fill with concrete. Make a larger pad on the corners, L shaped if you want.

I saw a neat trick to get flarred-out footers on that fhb site. I guess if I can get pretty good holes -- that removing the existing footers does not oversize the holes a bunch -- then I could pour all of it in one pour - footer and pad. That's where I'm questioning this a bit though. That might be a lot of concrete. I was planning to do the first couple just with mix.

Re: Pouring New Piers Around Existing Ones

Come to find out -- the original footers are 8" diameter,not 6" as I thought. I'm assuming they go down below frost line (36"), but have not verified. The problem - as is -- is that they are not centered under the 6x6 column they support. The column is suppose to sit directly atop the footer, but it does not.

Keith -- back to your idea possibly -- if 8" dia. is enough, then if I could get a new "pad" atop those, I might be able to use the footers as-is. With the "column sitting on the framing" approach I will get better load distribution, so being right over the footer is not as critical. That is kind of what they tried to do, but they did a 2nd pour of the larger pad, and it was not thick enough nor attached to the footer, so it broke away. In order to get it thick enough I'd have to knock off some of the 8" dia. footer, so the pad could sit lower.

Is there a way to join a new concrete pour to an existing concrete footer?

keith3267
Re: Pouring New Piers Around Existing Ones

I don't know if there is a "good" way to join a new pour on top of an old one. If I felt the need to do this, I would first cut off the top 4-6" of the existing footing. Then I would get a half inch masonry drill bit and a big hammer drill and bore at least three holes down into the existing footing. I would put in the 1/2" rebar into the holes and secure with hydraulic cement. Then bend the tops of the rebar 90 degrees and pour the new pad up to ground level.

The big question I have to ask, this is a big project. Do you really want to short cut on the foundation? If you do this part right, at least you will never have to do it again, even if you have to replace the deck in another 20 years or so. If you are going to do any short cuts, do them where it is the easiest to correct in the future.

Re: Pouring New Piers Around Existing Ones

Yeah, I understand. The existing footers are not way out of line -- only since the 6x6 column was suppose to sit directly atop, did the 2-3" make a big difference. If I could get a pad poured atop them, they probably would be fine. I'll probably try to pull one out -- and see how that goes. I'm not well equipped to handle concrete, so maybe that is why I'm trying to keep the existing footers if possible and reasonable. I don't think I want to prop-up the entire roof and pour all 9 holes at once, so I'll be working hole to hole. In that case, I'll probably be mixing my own and as you or another noted, that is going to be a lot of work. I do have one side and the entire front completely torn apart. I need to support the roof and start tugging.

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