pier foundations

greenspun.com : LUSENET : Countryside : One Thread

Could somebody out there please tell me about and how to build pier foundations for a 24x24 foot house with thoughts of building another 24x24 foot edition at a later date.don

-- donschwartz (donschwartz2002@yahoo.com), August 27, 2001

Answers

To avoid having the house settle (especially unevenly) at a later date, some of the calculations as well as the soil bearing capacity are important. For a single elevated floor 24x24 house, thats about 600 sq. feet, at 50psf for floor and roof, thats about a 60,000 lb structure (live and dead load). Assuming you'll put piers at 8 foot centers around the perimeter and through the center, thats 12 piers to support the 60,000 lbs. Each pier must handle about 5000 lbs. If your soil bearing capacity is only 2500psf, you'll need pier footings of about 2 sq feet each, thats about a 19" cicle. The footing will have to be approx. 9" thick (from a table). There is a handheld "something"ometer which can estimate the bearing capacity of the soil. The soil bearing capacity, number of piers, size of the structure etc. will all determine how you build the piers. I've no idea if my above calculations are exact, take them with a grain of salt.

cheers,

-- Max (Maxel@inwindsor.com), August 27, 2001.


Hello Don, My wife and I put in the piers for our A-frame back in the early spring. We simply dug square holes about 3 foot by 3 foot by 4 foot deep. We put four pieces of rebar in the center bending them in an "L" shape and allow them to come up out of the hole to the height of our piers. We poured the footers and let them set for two weeks. Our next step was to acquire 12 inch sonatubes. These incidently look like giant toilet paper rolls. We sat the sonatubes over the rebar a top of the footers. Then we pour the concrete in them and leveled off the top. Make sure that your piers are level with the string you use to level your site. You may have to trim a little off the sonatubes before you pour in your concrete. I cut them quite easily with my table saw. You can cut them with a handsaw as well. We poured six piers and used the walls of an eight by 10 foot cellar as support for our A-frame. Its fine and its level. Check our website and see the pictures! Sincerely, Ernest

-- http://communities.msn.com/livingoffthelandintheozarks (espresso42@hotmail.com), August 27, 2001.

When we built our barn, we put piers under it. We used sonotubes, but we also used something called a Big Foot, which is just a large plastic foot that fits over the bottom of the sonotube. You dig a hole that's quite a bit wider, put in the sonotube that's ductaped to the bigfoot, then you backfill around the sonotube. When you're filling you have to tamp the cement a lot to get it into the wide part of the Big Foot. The Big Foot gives the pier more stability. You can get the same effect by pouring a wider base with rebar sticking out, the putting the sonotube on and pouring to the level you want your pier at. I liked the Big Foot because I don't really like mixing cement all that much and it meant I could get it all over with at once!!!

-- Sheryl in ME (radams@sacoriver.net), August 27, 2001.

I would rather build a slab foundation myself.

-- ashley louise payne (lnc4@hotmail.com), January 28, 2002.

Moderation questions? read the FAQ