The concrete is cleared for all 11 foundation piers, so the next step is to excavate the 12″ diameter holes for the concrete foundation piers. The piers will be formed using cardboard Sonotubes buried to a depth of 48″. This is no job for a hand post hole digger or even a ice fishing auger style post hole drill. For this job you need something like the hydraulic Ground Hog hydraulic auger system.  It easily plows through most soils and will simply stall when you hit a rock. Luckily we only hit three small rocks that were easily removed by hand.
You can rent one of these units are your local hardware store – this one rents for $100/day and was well worth the price.

The trick to handling this beast is to get two heavy people on the bar near the motor (lower right) and push down while the operator is pulling up. This makes extracting the dirt much easier for the operator. We discarded a small portion of the excavated dirt but are keeping plenty near the work site to fill the outside of the sonotube foundations once the concrete is set up.

To see all posts related to this three season room project, click here.

It’s pretty much impossible to get all the dirt out of the hole with this machine, so be sure you have a hand type post hole digger and possibly a hoe to clear the final amounts of dirt. I found that I really could have dug further down just to loosen the clay, but since I did not do that in some of my holes, it looks like I have about 6 to 12 more inches to dig by hand. Our clay is like cookie dough.

Once all the hole depths check out, we’ll call in the concrete guy to pour the foundations. Concrete is one thing I typically don’t mess with simply because the contractors know how to mix it properly. Nothing would be worse than to spend all this demo and excavation work only to find that my foundations are crumbling and we need to start over.

It looks like rain in the forecast for the next few days, so the next post will be after the concrete pour. Stay tuned!

Find Remodeling Contractors. Get Up to 4 Quotes Now. It’s Quick, Free, and Easy!