Preparing Sonotube before concrete pour
1000eyes
| Posted in Construction Techniques on
I am in the process of replacing about 60 piers in my crawlspace. I will be using Sonotube for above the footing and an anchor embedded in the concrete on top of the tube. What I would like to do is have all the Sonotubes and anchors preplaced and secured before the pour. This way I can focus on pumping the concrete rather than fiddling with placing anchors.
Any ideas on how to secure the Sonotubes and anchors so they are ready before the pour?
Thanks
Replies
More info please.
Does the base of each tube sit atop a footing or pier that is already there?
What is the anchor? An "L" with threads on its long leg?
No, the footing and pier (sonotube) will both be new.The footing and the portion of concrete in the sonotube will be poured at the same time, so the sonotube will sit atop the footing essentially creating the "pier". The anchor is a Simpson PBS46 with the bottom being flush with the top of the sonotube.
The footings are 24"x24"x12"deep. The sonotube is 10" wide and 12" high.
Thanks
How much headroom do you have there and assuming these are replacements, how are you holding the house up while you work?
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Also, is your footer just trenched in or are you forming with wood?
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The footers are dug into the soil. There is about 3' of headroom. I have placed all the new piers between the old piers so the spacing is about equal. So the old posts and piers are currently providing support. I plan to leave the old piers since they are really causing no harm. I will then go in and place new piers anywhere that a girder has a joint landing on the old piers.
I should have been more clear when I said replacements.
Thanks
Edited 6/12/2007 4:23 pm ET by 1000eyes
Typically, I like to set the anchors after placing the crete, but I can see the delema here especially if you are working alone in such low headroom. That means you need to have the forms and anchors pretty well placed before you start.I would probably not bother with sonotubes for such a short space at all. I don't visualize what you gain with them there. I would probably drive a length of rebar for a grade stake exactly in the location where I want the anchor to seat, plumbed under the beam above and driven to the right depth. Then you can pour to top of it and still find it with your screed float, and seat the anchor right on it. The anchor is not in the way then.If for some reason you need to have the sonotubes, use two lengths of twoby to suspend them above the footer trench in the right place. A couple of Piffinscrews will hold the sonotube to the two by. Then buy up a bunch ( sixty did you say?) of lead fishing weights to hang by string from the beams. That way you can locate the right spot for the anchor quickly but be able to poke the mini-plumb -bob out of your way for placing the crete
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I don't visualize what you gain with them there
I'm thinking OP wants to make a concrete pier up, from the footer (which may or may not be meant to be cast monolithically), to the bottom of the various putative framing members.
If I'm on the same page you are, you are seeing simpson post anchor in footer, for a new timber vertical to the framing above.
Now we both could be wrong on this, OP may merely want to cut down on fussing-in-c/s time, and wants to rig some, oh, 16" tall 24" diameter "forms" up ahead of time. In which case, the magic answer is: <drumroll> hot melt glue. Set anchor next to some comvenient bit of scarp material, center came of ver sonotube section, hot melt tube to scrap material.Occupational hazard of my occupation not being around (sorry Bubba)
or - he could put the post in place with the anchor attached and leave it dangling over the empty footer and pour up to it.
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post in place with the anchor attached and leave it dangling
Yep. Hmm. What about ciphering up a common dimension for them all. Then pour them in forms with 5/8" allthread through the middles. Cast them all, and let them cure up. Then rig up box forms for the footers, and then, roll the piers to the footers. Just tip them up on the box forms, and set the footer 'crete. Anchor just gets bolted to the allthread out the top.
Hmm, couple of nuts and a fender washer would make a stout connection to the footer, cast in place, now that I ponder it a tad.Occupational hazard of my occupation not being around (sorry Bubba)
Well, now, that is closer to how I would favour. I was trying to work with his chosen anchor, allowing that he had probably ordered it or bought it already, but there is a better Simpson anchor that bolts down, and I have oodles of all-thread left-over in lengths from 2 to 3 feet. The allthread could be set or be dangled through a hole in a board across top of form
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Thanks for the help. Here is photo of the method that I devised. It holds the sonotube in place and the anchor. I thought of using the new wood post to hold everything but may need to do some minor leveling so that method wouldnt work.
Good luck getting it to stay there with the forces exerted from pumping concrete
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Unless you have an incredibly large house, why 60 piers?
Jeff
I will be replacing all the piers that fall under joints in the girders in addition to the new ones so it adds quite a few extra piers.
1000eyes, It has been mentioned by others that what have shown in your pictures will probably not withstand the pressures of the pour. I would recommend you devise some method to brace the sono tubes with diagonal bracing to keep them plumb. You can do this either by fastening a row of them to a single bracing system or do it individually but something should be done.
I also would say that I would pour all the footings for them first then come back around and fill the tubes. This will help contain the concrete in the vertical tubes."Poor is not the person who has too little, but the person who craves more."...Seneca
Yes I agree and will devise a better method of bracing.
Thanks
If you use a pier form such as those marketed under the name "Bigfoot" and "Redi-Base," you have a self-supporting form, in that the pier form, a big thing made of vacuum molded sheet PVC, has concentric rings at its top meant to receive a section of sonotube.
Here is a pic I clipped from the Bigfoot site.
View Image
Bigfoot pier forms are round, but the ones our lumberyard stocks have a square base. We just used a few of the small ones available, with a base size of 22 x 22.
As for your post anchor, I cannot right now think of a way to fix it in place so you can pour around and up to it, so all I can think of is wet-setting them right after the pour.
I am envisioning a nice use here for a dot laser, like the PLS5 we use. The laser could be jigged up so as to give you the line and grade you need for setting your anchors.
I had that in mind when I asked him how much headroom he has to work in under the house. To use those, he has to anchor them by covering with enough soil to keep them from floating up as the crete is poured. I don't see anybody enjoying shoveling that many tons of soil with 30-36" of headroom
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These squarebases that we get and use have a feature molded into the corners that accept rebar pins, used for fixing down the forms.
Why didn't BigFoot think of that?
There you go! A few wood stakes with screws into the plastic should hold, esp if driven at some angles.
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If your bases are in rows set foundation stakes to a line and screw 2x4s horizontally on both sides of the sauna tubes (like train tracks). Then screw the sauna tubes on both sides to the 2x4s. The sauna tubes will want to rock parallel with the line of 2x4s so you will have to put another 2x across and perpendicular to your previously set line of 2x. Cut a piece of sized material for each post base. 4x4 for a PB 44 and so forth. Establish a stake on either side of the sauna tube, rising above the top of the sauna tube. Attach another 2x between the stakes to screw into the 4x (or whatever). Screw through the 2x into the 4x securing the PB in place. Set string lines for all of the above prior to starting for stakes and Post Bases. It takes a bit to get started but will go quickly once you are organized. If you are under a house you can use floor framing above to attach stakes and brace if necessary. Good luck.
Mikfro
why cant you go ahead and attack to house and let post and anchor hang,
OK, here's my idea, feel free to poke fun at it everyone.
Yes, the post bases have some wiggle room, but you can pour the piers and get the bases in lin and plumb roughly where you want em. The sonotubes would be well braced and in line with the girder beam.
Not to scale, super quick drawring...
Judo Chop!