We are going to build a 40x64' metal building at our property in NWO. 18' side walls with loft in one corner. We are using perma column sturdy wall brackets on 5 1/2" x 5 1/2" x 18' posts that get bolted to the finished concrete every 8'.

The area we are in is unorganized with no building codes or inspections. I am having trouble figuring out how deep and proper diameter of footings. Does anyone have any experience in that area?

I have heard of putting pink foam board around foundation to trap geothermal heat so you can use shallower footings even if building isn't heated year round but not sure how deep the foam should go on that system either.

Any insight/experience appreciated.

I built a 60 x 100 metal building. 25 feet at the top. A metal arch actually. We poured the foundation at 3 feet wide x 16" deep. I did use 2 inch blueboard in the vertical plane. Ran it 4 feet deep. Also used the blueboard horizontally.........from the top of the concrete.....ran it out 4 feet.

This was all specified by the engineering drawings. Your soils and temperatures my differ significantly. Might be worth asking a local engineer to run some calcs for you. Also, we used 6 sacks to the yard for the concrete.

Thanks Ken. Is your building heated?

Call the local cement plant

I think we are 18" here for frost heave but not positive

Most of the winter there is some heat but the heat source is located 15 feet above the floor so the footing doesn't gain much if any from that. Thus, the foam board......to force any heat to travel under the footing.

Yeah, I wouldn’t think heat would penetrate much. Just maybe keep the cold from penetrating as far.

Do you remember how deep you buried the horizontal foam boards?

Good idea. Thanks

They overlap the top of the concrete and extend out at that same level. I then ran 9 foot wide Tyvek over that foam board and backfilled over it with about 6 inches of soil. The tyvek keeps the water from percolating down beside the footing and runs it off away from the perimeter

What I have done here is excavate to below frost and backfill with non frost susceptible (NFS) material then pour a monolithic thickened edge slab. That was an engineered design for Sherwin Williams Paint Store. It’s done this way a lot here.

Got ya.
When the foam overlaps the concrete do you have a grade board that sits on top of foam?

Thanks Snap. What did you use as your NFS?

No I don't.

Pit run that met NFS, test lab provided for the Pit, Particle Size Distribution report and Compaction Test Report for curve no. 22-459. That is what was used for the NFS from the pit that was supplied. On the Sherwin Williams project we went into ground water and started the backfill, that was about 5 feet deep.

10/4 Snap. Now I get it.

I'm having trouble picturing your foam on concrete set up white. Do your side walls sit on the foam or does the concrete extend outside the walls for the foam to overlap the concrete?

The concrete extends outside the walls by several inches. The foam is on top of the concrete and butts up against the walls

Frost map 5.9 feet in Ottawa Ontario

Even here if I wanted to be below the frost line I would look at 6 feet minimum. On a building that sized I would take into account the snow load on the roof too.

Now I get it Ken, thanks.

Thanks Mike.

I like the foam idea. I think it would have to be easier to heat the living area if there wasn't frost under the concrete so kind of a double purpose.

I am told 5’ in lake of the woods country

For whats it worth it sure doesn’t feel good to be investing money any more in Canada for how they despise us non residents. Imposing all these non resident takes and banning from buying land

Depending on what part of ONT you are talking, digging an outhouse hole can be a challenge with all the ledge rock, let alone a straight line for a slab and sunken foamboard.