We are glad that you are back for part two of our “How to Build a Root Cellar” building project tutorial. Now that we have the excavation done it’s time for us to work on the foundation and stairs. This has been an intense family project, a very rewarding one.
The first step was to backfill with 2 inches of gravel. As I mentioned in the last post, we realized we needed to dig a deeper footer trench on the edges. For that, we dug down an additional 6 inches and a width of 12 inches from the edge. This makes the foundation stronger to hold up the weight of the walls. We built a frame with 2×6 boards to hold in the concrete until it has a chance to dry. Support the frame with deep stakes so it won’t move or distort from the force of the concrete against it. We only dug the footers where the wall would be. The area of the door and front porch we left the original depth. These areas will not have the same amount of weight on them as the stairs and walls.
Now that the frame was built we needed to put in the rebar supports. Rebar adds strength and stability to concrete improving its structural integrity. The rebar needs to be in the center of the concrete so rust cannot get in and degrade it. There are special supports you can get to help it hang in the right location. Or you can come up with something on your own like we did. We placed #4 rebar deep in the footers and made a grid across the floor itself. You want to grid the rebar somewhere around 1-2 feet apart. Be sure to have the whole perimeter of the root cellar floor covered as well.
My husband came up with an inexpensive way to bend rebar with a few items we had on hand. He started by cutting a groove in a board the same width as the rebar.
He then placed the rebar in the groove with the end sticking out a little and sandwiched it with another board. The second board was placed slightly off from the end.
At this point, he placed one foot on the sandwiched boards to keep them together and stop them from moving.
He then placed a metal pipe over the end of the rebar and pulled it up towards the boards.
This created a perfect curve for us to use on our corners since all the rebar needs to be connected to each other.
Root Cellar Concrete Foundation:
Now that the rebar was in place we were ready for the concrete truck. We ran into one problem. The deliveries were not available for another 2 months unless you were a contractor. Since we aren’t contractors we got on a list for any cancellations and luckily only had to wait a few days before we got a call. Unfortunately, this also meant we were not expecting the call.
My husband had to go home early from work so he could do the work. We also hadn’t had a chance to get all the equipment we needed yet including a large float. Which I would say is absolutely needed for work like this. In addition, it was a day that Emmaline and I were recording canning videos so I wasn’t available to help. Had I realized the issues he was having I would have postponed recording canning videos and went to his aid.
He was using long straight boards and a trowel to even out the concrete but since he was alone and a novice to concrete work it was drying faster than he had time to work with it. With a structure this size, I would recommend at least 2 people and definitely to have the right equipment. Not only did the surface end up with more irregularities than we would have liked, but he wore his old work jeans which have holes in the knees and ended up having the lye from the concrete eat into his skin. He used rubber boots and large rubber gloves, which was good, but it wasn’t enough. Please learn from his mistake and protect all of your skin. If you do get concrete on your skin, wash it off immediately.
Fortunately, we can use a concrete leveling component when we are done with the structure to give us the smooth floors we desire. (This photo also has some gravel on it that will easily sweep off from when we were working on the stairs.)
The next step was to remove the wood frame. This was a little harder than I would have thought primarily because there was not much room to fit a screwdriver in to take the screws out. Hitting the boards with a mallet helped to break the bond with the concrete. We then had to slowly work the board up and off the concrete. Pry bars worked pretty well for this but it was still hard work. If you had a Sawzall you might be able to just cut through the screws. Another option would be to dig your hole bigger at the start.
Now that the root cellar floor was complete we needed to put in the stairs. This had to wait until after our trip to visit my brother in Louisiana. Unfortunately, the last day we were on vacation an infection spread from my husband’s concrete injuries to the bursa in his knee. This necessitated an ER visit and made it impossible to kneel on his knee for an extended period of time. Once he was finally healed we could get back to work on the root cellar.
Root Cellar Stairs:
Finally we got around to stair construction. We started by digging a ramp-like incline about 1-foot deeper than where we wanted the top of the stairs. Then we added 2 inches of gravel on the incline and built a frame for our concrete stairs. We determined we wanted the stairs to be wider and we were willing to have deeper stairs in exchange. Our stairs are about 10 inches deep. The general recommendation is 7-8 inches, but for us, we felt 10 inches was not unreasonable. We made the frame by figuring out the angle needed. This area was a little more limited because we were trying to match it up to our cobblestoned area.
We wanted the stairs to overlap the porch by enough that we could tie it into the previously poured floor. Then we spaced the stairs out and used a level to first mark and then place all the stair boards at equal distances up the side-boards.
After we placed the stair frame, we added a steel mesh underneath to give the concrete something additional to adhere to. This added to the strength of the stairs.
We then used a concrete drill to drill the holes into the porch so we could tie the two sections together.
The holes need to be blown out and rebar pieces cut so they will fit in the stair area.
Now you want to epoxy the small rebar pieces into the holes you created. These will help to lock the two pieces of concrete together.
We also placed cinder blocks at the bottom to help hold the frame in place. We were now ready to pour the concrete. We used a slightly wetter mix as it flows better. I highly recommend using a concrete vibrator to help remove the air bubbles. We didn’t get ours until after this pour and I feel like it would have been much better if we had it previously as there were air bubbles in it that we didn’t find until later despite our best efforts to avoid them as we were going. We tried to angle our stairs slightly forward so that water wouldn’t pool on them. For each stair we created, we added two pieces of rebar lengthwise suspended in the mix.
The last step was removing the frame and seeing how it turned out. Be gentle with the corner as these are a little more prone to chipping. We made our stairs extra wide so we can have our bricks cover the edges of them when we put in our stairwell retaining wall.
This completes our second step.