Root cellar when you can't dig too deep due to rock

I hit rock at 2 ft, how can I build myself a root cellar on the area that was dug?

Hi Beth,

Welcome to Permies!

Knowing your location would help.   But, being blind to your location, here are some thoughts:

The rock may be singular to a specific location on your property.  Check other spots .... assuming your property is large enough to have other spots to check.

If your house has a basement, you may be able to make a modification.

Sticking to the current spot, your only real option that I can see is to build up.   I would use concrete blocks.  Others might use logs.   Mound up a substantial amount of earth on the walls .....measure in feet ....not inches.  Of course the roof is critical.   The more it is insulated from the outside, the better.  Earth would be my first choice ......but that takes a good deal of care in the construction.   You may need to explore other choices.


I am certain there will be others who reply with better ideas than mine.

People traditionally think of a root cellar being below ground, but in fact most that I've met have a building over them to keep them from turning into a swimming pool.  So if you're thinking of a stand-alone, I'd look for a bank you could dig into, (north slope) or some other way to insulate and shade it and where you're sure the water can drain.

Here are some good links on permies to give you ideas:

https://permies.com/t/165961/Root-Cellar-Fire-Shelter

https://permies.com/t/164291/earthbag-cellar-double-survival-shelter

I do think we need a strong revival of root cellars - non-electric food storage is important and I hope you can find a way to make yours work and be safe!

Thank you

Thanks. We are truly off grid so we have to have one.

Insulation on a raised structure is hard to do compared to burrowing into the stable temperature regimes of the mother earth, but it's not impossible.  The classic ice house for preserving lake ice year around relied on several feet (think interior frame shell and exterior frame building) of sawdust in the walls -- but also benefited from having all that ice in there.

On the other hand, people have been burrowing into the mother rock since mining was invented, maybe 10,000 years ago.  It's not that you can't dig rock, it's just a lot more work.  Sure, these days they use dynamite because it's easy, but the classic rock drill (piece of steel with a chisel edge, hit it with a hammer, turn it half a turn, hit it again, keep doing this until you have a hole) still works.  A big heavy hammer drill or jackhammer (powered by AC current or a stalwart air compressor) makes it a lot easier.  If you're off grid, a  generator too. Depending on what kind of rock, this may be the work of a lifetime or "just" the work of a summer.

Once you've got a series of holes, you can start hammering wedges into them until you have cracks.  Then you hammer more wedges into the cracks.  Eventually a chunk breaks loose.  Now we have progress!  Throw that chunk out of the hole.  Look for another crack, wedge off another chunk.  No cracks? Get out the drill again and make some!  It's hard work but it's not complicated.

Easy to say, hard to do!  Worth it?  Nobody knows but you.  I grew up in the goldfields of Alaska and the number of small tunnels (mostly just head-and-shoulder sized) I found where some ambitious prospector chased a promising vein was pretty amazing.  In most cases they did it all with a hammer and a bar, because the dynamite supply chain was ridiculously long.

Thank you

I have seen holes drilled into the rock, filled with water and when the water freezes it splits the rock.

As somebody mentioned, is there another location suitable?
Very often rocks come in the form of 'floaters', in that they are not a footy field size.

We had a similar problem, but for us it was a high water-table that kept us from digging down. So we built on grade and began the long ordeal of hauling in dirt to build up around our circular earthbag root cellar. It is a lot of work and takes a lot of dirt, but if we can achieve our goal of zero-energy refrigeration, it'll be worth it. We are currently adding styrofoam and polyethylene to the berm to try to moderate the temperature swings and hope to not need our 12v cooler next summer.

Are photos possible? Thanks

Lots of videos on drilling holes and filling them with stuff that cracks the rock:
https://www.youtube.com/watch?v=dPfqitM2Dt4

The Mike Oehler book on Underground houses has a section on flat-land designs, those might be helptfull for you.

We live in a place called stone county, but I wish there was. This is even dug into a hillside and 2 ft was all they could go with an machine digging it.

Dan Boone wrote: On the other hand, people have been burrowing into the mother rock since mining was invented, maybe 10,000 years ago.  It's not that you can't dig rock, it's just a lot more work.  Sure, these days they use dynamite because it's easy, but the classic rock drill (piece of steel with a chisel edge, hit it with a hammer, turn it half a turn, hit it again, keep doing this until you have a hole) still works.  A big heavy hammer drill or jackhammer (powered by AC current or a stalwart air compressor) makes it a lot easier.  If you're off grid, a  generator too. Depending on what kind of rock, this may be the work of a lifetime or "just" the work of a summer.

Once you've got a series of holes, you can start hammering wedges into them until you have cracks.  Then you hammer more wedges into the cracks.  Eventually a chunk breaks loose.  Now we have progress!  Throw that chunk out of the hole.  Look for another crack, wedge off another chunk.  No cracks? Get out the drill again and make some!  It's hard work but it's not complicated.

This is great advice!

When we had our storm shelter installed they took out a massive amount of rock.  I am not sure I remember what kind of equipment they had,  It might have been a trackhoe or a backhoe.

An auger will help break up the rock, too.  I have seen dear hubby use the bucket on our tractor to break up and lift out rock.

With a little inginuety it can be done.

I have personally used a rock drill and "feathers and irons" to break big rocks into smaller rocks (we grow rocks really well on our land and some easily compete with a Smart car in size!) Since we're on land that was under the ice sheet in the last ice age, the types of rock can be quite jumbled up, and some rocks definitely split more easily than others.

"Solid" consistent rock splits easily - stuff that's multiple layers every which way can be a struggle. The only way to figure out which you've got would be to try. I've seen a fellow saw rock with a special diamond blade on something like chain saw but circular who cut himself a small house out of solid, but soft-seeming rock. The problem could be the solution if you can break up the rock into a form where the rock is useful to build with.

Some ideas of your year-round weather pattern and an actual name for the type of rock you're dealing with would be helpful.

I will ask some of the natives, we are moving there.

I and a couple other fellows jack hammered a 6'x6'x6' hole in solid rock in a morning.  The jackhammer was run by a large diesel compressor.  The jack and compressor could probably be rented for less than $1000. The rock was softish and came out in layers.  Harder rock could have made things significantly more difficult. Removing the broken rock from the hole was as much work as running the hammer.  Somebody misjudged the size of the hole we needed which left us jackhammering on the walls of the hole, not recommended!  

Gray Henon wrote:I and a couple other fellows jack hammered a 6'x6'x6' hole in solid rock in a morning.  The jackhammer was run by a large diesel compressor.  The jack and compressor could probably be rented for less than $1000. The rock was softish and came out in layers.  Harder rock could have made things significantly more difficult. Removing the broken rock from the hole was as much work as running the hammer.  Somebody misjudged the size of the hole we needed which left us jackhammering on the walls of the hole, not recommended!  

1. Yes, removing broken rock is hard work and can easily get people hurt if they're not used to it/built for it. I would recommend setting up some sort of a sturdy tray and a block and tackle, so you can stack the rock on the tray and lift, once you're deeper than 3 ft. Human shoulders aren't that well designed from the "tolerates abuse" side and this is *particularly* true for many women who biologically have fewer muscle cells in key shoulder muscles than those humans with Y chromosomes.
2. Yes, having to drill or hammer laterally rather than straight down is *considerably* harder and beyond me now - Hubby's job!

When we get to our property next week, I will send some

Hi.  We are considering where to put a root cellar and how to build. We live in northern Ontario and are off grid, so it’s a priority, but we are on bedrock.  Main question is if we make a concrete stem wall on bedrock and then build wi the salt preserved logs and surround the cellar logs with extra dirt. Is it too cold if the floor is bare bedrock?   Obviously we would choose a slight hill by the house to prevent flooding but our home is on bedrock and bone dry.
Thoughts anyone?  

Kristin Lang wrote:Hi.  We are considering where to put a root cellar and how to build. We live in northern Ontario and are off grid, so it’s a priority, but we are on bedrock.  Main question is if we make a concrete stem wall on bedrock and then build wi the salt preserved logs and surround the cellar logs with extra dirt. Is it too cold if the floor is bare bedrock?    

Given your climate, I think it's going to be hard to keep veggies from freezing. A better option might be to build a heavily insulated "cold room annex" onto the house itself to make use of the residual heat that escapes through the wall in winter, with ventilation options to control temperature. My 2c.

Kristin Lang wrote: Is it too cold if the floor is bare bedrock?  

I'm in Northern Ontario too. We only have a few small areas of exposed bedrock, but I had considered building on it. I couldn't find an answer about whether bedrock had any noticeable effect on ground temperatures. Years ago, I cleared snow from a small area in order to check the temperature with a laser thermometer. I don't remember the exact result, but I was surprised at how much warmer it was than the ambient air temperature. I've noticed on frozen Lake Superior, that bedrock shores always tended to resist freezing. That's as science-y as I can get.