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

For my porch , what about using this approach -- http://www.finehomebuilding.com/how-to/video/build-a-deck-posts-rim-beam.aspx -- pour the footer/pier, using the bracket attach a 6x6 PT, cut it height and notch for the rim joist?

keith3267
Re: Pouring New Piers Around Existing Ones

Nothing wrong with that method, in fact it has a lot of advantages for you. You can reuse the existing footers that line up with the edge of your rim joist. You can't reuse the ones that are in too far or out too far. You don't have to worry about those broken "collars" either, just get rid of them. Use a masonry drill and anchor bolts for the metal brackets and if you add the copper napthenate to the step cut as recommended, I would add some to the bottoms of the posts as well to give a little more protection to the end grain as well.

The wood posts have another advantage as well, you have a better surface for attaching a skirt if you want to.

Be sure to use coated or stainless steel screws for this. I would not use nails. The reason is, should a post rot on you, you can use a piece of 4x4 or similar to support the joists behind the post, jack them up ever so slightly and then unscrew the rotted post and replace it. You won't have to tear apart any of the porch or support the roof.

In fact, if you are cleaver enough, you may be able to install the new posts one at a time right now. Just get a pair of bottle jacks, a section of 4x4 or 6x6 and run it along behind the current post to support the joists, or if you have the joists running parallel with the wall and attached to Perpendicular joists every 8" or so, then just use the jacks directly under the perpendicular joists. You won't need the temporary roof supports that way.

Re: Pouring New Piers Around Existing Ones

Keith - thanks for quick response. I thought about this last night. I agree -- there seems to be a lot of advantages. What about at the corner? Do I try to notch away 3" from both edges? That just leaves 2.5" x 2.5" remaining. I have 2 corners. The others, even if I double up the rim joists, leaves 2.5" x 5.5" which should be plenty. Or at the corner should I just notch one side and use a hanger to attach the other "rim joist".

My son & I jacked up three last night. After lifting one -- and the letting down the jack, it did not even sit back down. Yet I'm pretty sure all are load bearing. The corner definitely is -- and one other line did come back down. We used a 2.5 floor jack. After that, we got an idea -- just drive wedges in at the bottom to drive up a 2x8 or 2x10 into the beam above. That worked well for the lines, not as well for the corner.

We have all the rim, ledger, and joists torn out -- just too much rot, etc to deal with -- better to start over. I don't think we can reuse the footers/piers -- they are 2-3" out of where we need them. We are going to try to pull one out today/tomorrow. My old footers/piers are 8" dia.

I like the PT 6x6 because:
a) it gives me wiggle room to make side to side adjustments
b) it give me wiggle room to make vertical adjustments (the major advantage)
c) as you noted as well -- it really makes future repair very easy

Re: Pouring New Piers Around Existing Ones

Yeah, I'm liking the idea more and more.

Friday night my son and I used a floor jack to lift up three columns. One did not even sit down tight after we let down the jack -- but I'm still pretty sure they are load bearing. We then propped up a 2x8 and using wooden wedges repeated the lifting. The ones in the middle lifted fairly easily, but the corner was a bit more difficult.

I like going with the 6x6 PT piers for all reasons you mentioned, and mostly because it gives me some wiggle room in all three dimensions. But those metal brackets are not cheap. I bought a couple last night -- http://www.menards.com/main/tools-hardware/fasteners/connectors-reinforcements/caps-bases/post-anchors/triple-zinc-post-anchor-2-sided-6-x-6/p-1342922-c-8828.htm -- at $20 each. I found the Simpson version ****** for about $15.

I doubt I'll be able to use any of the 8" footer/piers. Most are off by 2+ inches, and so getting that bracket even close to centered is impossible.

We'll see how pulling out the old footer/piers goes..

Re: Pouring New Piers Around Existing Ones
keith3267 wrote:

In fact, if you are cleaver enough, you may be able to install the new posts one at a time right now. Just get a pair of bottle jacks, a section of 4x4 or 6x6 and run it along behind the current post to support the joists, or if you have the joists running parallel with the wall and attached to Perpendicular joists every 8" or so, then just use the jacks directly under the perpendicular joists. You won't need the temporary roof supports that way.

I have the framing torn completely apart -- ledger, joists, rim -- gone. The columns are just sitting atop their 8" pier/footer (some of it anyway).

Re: Pouring New Piers Around Existing Ones

How would you suggest I handle the corner using those 6x6 PT piers? For the ones in the middle I can rabbet/notch out for the pair of 2x8s -- that leaves 5.5" x 2.5" of pier. At the corner, do I notch it all out as well -- leaving just 2.5" x 2.5"? I guess that's still a fair chunk of material, and all the weight is transferred down. In the video, they just have the single rim, and the outside edges are joists.

Another thought -- do I really need a double 2x8 rim joist? Somewhere I read a comment that suggested avoiding doubling up on exterior projects if possible. Water tends to get in between the two pieces. That makes sense. I could drop in a 2x10 rim I suppose. The spans at most are 10', some closer to 8'. This is pretty accurate now -- http://oi50.tinypic.com/ifwdmv.jpg

keith3267
Re: Pouring New Piers Around Existing Ones

On the corners, notch out both sides. Step the rim joists on the corners so that when you look down on them, they look like a herringbone pattern. I would still double the rim joists, If I recall, you are using tongue and groove decking so water will not get in between the joists, but it wouldn't hurt if it did, you are using PT.

Re: Pouring New Piers Around Existing Ones

I rethinking my choice of flooring - it was t&g - I'm considering just PT decking. The t&g requires I run them perpendicular to the house, thus I need the joists and then blocking in between the joists. Planks would just need 16" oc joists. It seems planks would have a longer lifespan. Just thinking about it at this point.

Re: Pouring New Piers Around Existing Ones

Should I put rebar in the footer holes? I noticed in the FWW series -- http://www.finehomebuilding.com/how-to/video/build-a-deck-footings-piers.aspx -- they did not. I can flare out the bottom of the hole. Should I use rebar at all?

keith3267
Re: Pouring New Piers Around Existing Ones

You probably don't need rebar for this as long as you are not trying to tie a new piece of footer to an existing piece. As long as it is one pour, you should be OK.

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