Underground Root Cellar Construction

[edkemper]

Jarhead,

I've come late to this conversation but may have something to add.

Rebar.

Log walls with log roof sitting on top of the walls. Rebar pin the roof logs to the wall logs. You can drill the logs, but make the holes 1/8th" smaller than the rebar. Then put a few layers of plastic on top. Ain't going anywhere.

[OlJarhead]

Jarhead,

I've come late to this conversation but may have something to add.

Rebar.

Log walls with log roof sitting on top of the walls. Rebar pin the roof logs to the wall logs. You can drill the logs, but make the holes 1/8th" smaller than the rebar. Then put a few layers of plastic on top. Ain't going anywhere.

Thanks!  I'm seriously thinking of using RR Ties to frame the walls and then logs on top.  Was thinking of 12" galvy spikes to hold it together but Rebar would work too.

This spring will be the time when I have to settle and make it happen

[Bandmill Bandit]

Hey Jarhead

i think we may have talked on the phone about this but may have been some one else that was doing the same thing.

We built one into a hill side for my dad about 25 years ago.

We used 12 inches of 2 inch washed drain rock as a base with good pine 3 by 12 "bull pen rails" as footing. we sprayed those with a wood preservative 5 or 6 coats and then used 2x8 PT pine on 12 inch centers with 3/4 inch PT plywood outside sheeting that ran down to the bottom of the 3"x12". we insulated to 6 foot below grade and lined with 3/8 spruce plywood. bottom 18 inches is not insulated or lined. We used 3/8 rebar as big nails for joinery at base and roof line. Cut to needed length and the pre drilled the holes to put them in place.

3 rooms, front room is air lock and storage for containers used in the cellar and measures 4'X16' the 2 back rooms measure 8' by 8' (outside). One side is used for root veggies and such while the other side is used for canned preserves, ciders/juices, and wines. Roof is railroad ties set on edge with PT 1/2 inch ply wood on top and inside ceiling 3 sides and top of structure were  wrapped in black plastic and then backfilled with a top side over burden that is settled to about 2.5 feet now. Vents are 4 and 6 inch PVC pipe with adjustable vent doors.

Railroad tie retaining walls V'ed back at 45 degree angles to give a good working area out side the entry door with a good 12 inch deep 3/4 inch road crush apron to park/work on.   



 

[OlJarhead]

Hey Jarhead

i think we may have talked on the phone about this but may have been some one else that was doing the same thing.

We built one into a hill side for my dad about 25 years ago.

We used 12 inches of 2 inch washed drain rock as a base with good pine 3 by 12 "bull pen rails" as footing. we sprayed those with a wood preservative 5 or 6 coats and then used 2x8 PT pine on 12 inch centers with 3/4 inch PT plywood outside sheeting that ran down to the bottom of the 3"x12". we insulated to 6 foot below grade and lined with 3/8 spruce plywood. bottom 18 inches is not insulated or lined. We used 3/8 rebar as big nails for joinery at base and roof line. Cut to needed length and the pre drilled the holes to put them in place.

3 rooms, front room is air lock and storage for containers used in the cellar and measures 4'X16' the 2 back rooms measure 8' by 8' (outside). One side is used for root veggies and such while the other side is used for canned preserves, ciders/juices, and wines. Roof is railroad ties set on edge with PT 1/2 inch ply wood on top and inside ceiling 3 sides and top of structure were  wrapped in black plastic and then backfilled with a top side over burden that is settled to about 2.5 feet now. Vents are 4 and 6 inch PVC pipe with adjustable vent doors.

Railroad tie retaining walls V'ed back at 45 degree angles to give a good working area out side the entry door with a good 12 inch deep 3/4 inch road crush apron to park/work on.   

We did!  And thanks   You were the one that convinced me that I was on the right track but I got busy with other parts of the project.  Most likely I'm going to build a variation of your root cellar though with this post I see a couple things I missed on the phone with you.

Thanks again because it's likely mine will be very similar!

[OlJarhead]

The saga continues.

A recent discussion with a neighbor made me think that a combination of the ideas presented here and elsewhere might work very well:

Cinder block and concrete walls, heavy timber roof construction covered in 60 mil plastic.

Due to the location there is NO WAY a concrete truck can get in and carting tons of concrete bags is also out of the question (my 1/2 ton truck could perhaps handle a fair amount in one trip on a smooth hiway but my driveway with it's 16% grades etc isn't likely to make it as easy as that!

A neighbor has a mixer though, and with some serious effort and lots of bags of concrete we could pour a foundation, stick rebar in it (to fix the blocks in place) and then begin stacking blocks on top of the foundation (once it sets) and then fill them afterwards with concrete.

This reduces the overall concrete needed to make the walls yet still makes a pretty solid and strong wall to support the heavy roof.

Then we put 10" logs on top of the walls every 2' or less (maybe every 12" but I think that might be overkill (still looking for load bearing info) and drop a 2x6 lid on top of that from my mill.  Finally after putting in vents and doing a little concrete work around the log ends to keep them in place (also use rebar for that through the log and into the concrete walls) we can cover with 60 mil plastic to ensure it stays dry.

I'll put in drain rock on the outside of the footings and french cesspits for added drainage to help keep the water out.

The 'airlock' or 'dry' room will get a concrete floor also while the root cellar remains a dirt floor.

Then when all is done I'll build a cinderblock stairwell to the surface and build a 'garden shed' right on top of the stairwell to provide cover for it so it doesn't build up snow and rainwater and adds a little security.

Thoughts?
Thanks
Erik
 

[jueston]

sounds like a well thought out plan, and like one that balances the difficulty of getting materials in with the need for strength.

i really like the idea of the garden shed over the access door, makes it all seem very secretive....

[OlJarhead]

Out of sight, out of mind

But it also helps keep it cooler in the summer by insulating it a bit more from the summer heat as well as solving the problem of keeping out the winter snow or spring rain.

Also solved the the problem if how to get enough headroom in the stairwell down to the 1st room (Dry room).

Once the orchard is in and producing (4 to 5 years after putting the trees in) it will provide a good place to store excess fruit and if we ever start farming then a place to store root crops as well as dry goods (wheat etc) that we might want to store for long periods.

For me, a farm without a root cellar is like, well, not a very good farm!

[ljmathias]

Wow, talk about overbuilt!  Tell us the truth, now: this is really a bomb shelter/safe room in case of some natural or man-made disaster.   

Your plan will work fine but I don't envy your back pains- lifting concrete up to pour in the blocks will be a killer or do you have a FEL to help with that?  Way I addressed this when forming up the blocks for the raised slab I built was to use the bucket of the FEL as my mixing trough: pour in 2-3 bags of sackcrete, add water, mix with a hoe, and then carry it to the wall where I could easily shovel it in and pack it down.  Don't skip the packing down part- big air bubbles can form.

Are you going to put membrane seal on the outside of the block walls to keep moisture out?  Since you're going to all this trouble, why not go that extra step and make it dry as well as secure?  I understand the new sealants are pretty good...

Lj

[OlJarhead]

Overbuilt?

I really have no idea what I'm doing which is why the posts of course.

I planned on building the whole thing out of wood but started to shy away from doing so for various reasons and because of the location I can't just have someone pour it with a concrete truck and pumper truck so this was an attempt at a compromise.

And no, not a bomb shelter etc, just a root cellar.

I'm putting in a small orchard but hope some day to farm the land and so the root cellar would be vital for an off-grid farm.

[beenthere]

As you are off in the forest, it should be a good safe place for protection from a forest fire.

[jueston]

we will know for sure when we see the door. if its 6 inches thick its a bomb shelter.... the pictures when its finished will give us the answers we are looking for...

[OlJarhead]

As you are off in the forest, it should be a good safe place for protection from a forest fire.

Might be, as long as you keep trees away so the fire doesn't suck the Oxygen out!  But it should also be a secure place to store things you don't want unwanted guests to get at.

[OlJarhead]

no 6" doors!  Though...now that you mention it....

Nah haha just a good steel exterior door with an extra lock or two.

Of course if the garden shed is well constructed and stocked one might not even know there is a cellar under it

[SwampDonkey]

just a good steel exterior door with an extra lock or two.

Are the bears that troublesome out there?

[OlJarhead]

Actually bears could be a problem though the closest I've seen tracks is about 1000 feet from the cabin up on top of the hill.

Meth heads are more likely an issue but up there it's a little less likely then closer to town.

However, I've been told that if it isn't tied down it's likely to eventually take a walk so tie it all down and lock it all up.

[OlJarhead]

http://www.drystacked.com/sequence.html thanks to another forum I did a search and found this.

I beleive using this method of building the walls I can get it done much faster then a traditional mortar job.

My biggest challenge now is both to cut and mill the logs without ridding myself of all good logs and of course, getting someone with knowledge to come out and help with the foundation pour.  I've done some concrete work but want the floor in the dry room to be well done and everything else done right too so figure I'll have to con a work buddy into the long treck up to the cabin as he has all the tools and the knowledge

[SwampDonkey]

I thought you were more remote. I could go to areas around here and never hardly see a soul all winter, probably no one at all. In fact, I could go to the woodlot this time of year, which is 3 miles away and I know no one will be there this winter.

[OlJarhead]

Nearest town is ~23 miles away and has only about 900 people in it.  Another is about the same distance if you travel 4x4 roads and forest roads to get there (so takes longer) and has about 1200 people.

Have a neighbor about 1/2 mile away through the forest (rumor has it one of the kids living there -- kids being in their 20's or 30's -- is wanted by the law in Michigan) or about 1/2 to 2 miles by road and another neighbor about 3/4's of a mile away (more buy road).

Nearest store is about 3-4 miles and it's all by it's lonesome (as in no other stores etc for 20+ miles).

So we're fairly remote but I've learned that no matter how remote and hidden you are you could still be found and left with nothing by those who like to do that sort of thing.

[Bandmill Bandit]

Looks to me like you have it pretty much built in your head and I think it sounds about right. Over built is better then poorly built. One other thing for materials to use if available is Tamarack logs and lumber. Need to get that stuff in place ASAP after it comes of the stump but it will out last any thing treated that I have ever  seen.

I swear the stuff grows petrified.

[OlJarhead]

Looks to me like you have it pretty much built in your head and I think it sounds about right. Over built is better then poorly built. One other thing for materials to use if available is Tamarack logs and lumber. Need to get that stuff in place ASAP after it comes of the stump but it will out last any thing treated that I have ever  seen.

I swear the stuff grows petrified.

Hmmm, I have some Tamarack though I planned to let it grow to eventually cut and burn in the woodstove...most of my trees are under 10" in diameter though I think, whereas I have a lot of pine that's big enough and perhaps enough Fir....I'll check again though!

Thanks