Another footer question

[brian_nj]

This may sound a little silly but I am not sure so I would like opinions. We have changed our foundation design to use piers and I am getting ready to get the materials for them. The thing I am having difficulty with is a form for the footings. I plan on using 8" sonno tubes but was planning a 24" diameter footing. I am having trouble scrounging materials that are 24" diameter. I can get plenty of scrap wood to make 24"x24" footings for free and was wondering if there was any drawback to making the footings square versus round when using post and pier construction? Pouring into the bottom of the hole is not an option as we have to over dig most excavations due to rocks we encounter and I do not want to have to hand mix extra concrete if at all possible.

[John_C]

Square footings are common. No problems with that.

[Redoverfarm]

Brian I can see no reason that you could not use anything to maintain a form size which would eventually support the 8" sono tubes.  In fact if it were just the footings that you are forming I would probably just use the earth as the footing forms. I would drive some short pieces of rebar to guage the thickness of the footing.  Just make sure that they are sufficent depth (8,10 or 12" deep) with the bottom being below any frost depth.   Reinforce with rebar and then allow a couple pieces of rebar to protrude up to within the last 3" of the top of where the sono tube will be.  With an 8" sonotube a 18" footing would probably suffice.  Nothing says that it has to be round just because you are using sonotubes which are round.  It just has to have a bigger footprint than the sonotubes by approximately 2/3 bigger.  Others may disagree so that is just my $.02 worth.

[Bill Houghton]

I just looked at this web page about the bigfoot bases for pouring piers.  There is a video on there showing framing square footings (they make it look real frustrating because they want you to buy their items instead) but it can give you the general idea.

http://www.bigfootsystems.com

Bill in the U.P.

[brian_nj]

Thanks all, I figured it did not matter but it's one area that I did not want to take any chances with I'm hoping the weather is cooperative and we can start poring in two weeks. I am going to get all my forms built this week and just transport them to the site to save some time.