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I wanted to share with you and your readers how I built an underground root cellar in my backyard.

First I marked out a rectangle on the ground measuring 8’x12′.  Then I set to work with my post hole digger and dug a 6″ wide trench 6 and a half feet deep all the way around.  Next I tied re-bar mats and slid them down in on all four sides.  I used 8′ chain link posts as digger handles after about 4′ of depth. Then I lined the inside of the trench with 1/8 inch Masonite paneling and poured the trench full of concrete.A couple of weeks later I had a friend come over with his backhoe and dig out the center.

That produced about 25 cubic yards of dirt, (which I used my father-in-laws Bobcat to scatter over the back half of my large lot.)When I poured the concrete walls I embedded redwood 2×4 “sleepers” and leveled them on all four sides.  Once the inside was dug out I peeled the Masonite panels off exposing a very smooth interior wall.  I dug a sump hole in the corner deep enough to put a 5 gal. bucket in which has 1 inch holes drilled around the sides near the bottom and a float operated sump pump place in it.  I poured half the floor in concrete and put a layer of gravel on the other half.When that was done I placed floor joist across the 8′ way and built a garden shed on top of it.

The ceiling of the cellar is paneled with 1-1/2 inch styrofoam sheets and there is R-19 insulation between the floor joists.  A trap door in the floor provides access to the cellar.  I installed two 3 inch diameter ceiling vents and two 3 inch diameter cold-air inlets at floor level to help with air exchange. I live in the Sacramento Valley where summers can be very hot, and the cellar temperature is usually around 50-55 degrees and colder in the winter.






Here are some pictures.  I am not quite done with the project.  I don’t have permanent stairs/steps









going down yet… I have been using a 6′ step ladder



I plan to insulate and panel the interior as well before building shelves and cabinets.The white plastic pipes on the outside are the cold air inlets that go down the inside wall to about 6″ from the floor.









One has a hose running up through it that facilitates the sump pump which pumps about 2.5 gal. 2-3 times an hour in the winter and less than once an hour in the summer.  In the summer I plan to move

the hose around to my fruit trees


The air outlets are flush with the ceiling and are vented into the attic.  The attic has a little over 4′ of vertical storage space with a generous access hole for larger boxes/items.








I laid it out to be 8×12 so the 4×8 wall sheets would have no waste or extra cutting.  The walls are only 7′ tall so my wife won’t need a stool to reach stuff on the top shelves.  Each roof section is exactly 4×8, again for no extra cutting or waste.  I drew out the truss angles on the driveway making the the ridge sections match a 4/12 pitch and sloped the bottom sections out until they

reached the









We have grown a garden and done a little canning for a couple of years now, but it seems time to get serious.  We plan to put in about 400lbs of potatoes, lots of squash, carrots, and the other usual suspects that store well.  We plan to increase our canning of fruits and vegetables by a great deal as well.  I have done much reading and research on root cellars and feel this will meet our needs well.  Hope this is useful to someone.






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