Outhouse Footing/Foundation

[Adam Roby]

I am drawing up some plans for an outhouse, (I unfortunately forgot to send the sketchup snapshots from work so had to draw a crappy Paint picture for this question).  The question is with regards to how best to lay this thing down.

I know on a cabin I would need to dig 4' to get below the frontline... but this is a 4' x 4' poop shack.  I was thinking of digging the hole, lining it with a kind of cage of wood to keep the earth out.  Then do a perimeter footing about 8" thick and 8" wide, with about 2" of that sticking up above grade.  I figure it will move around a bit but at least the entire building will move synchronously.



Also, I am considering using 1x6 fence board and lay them horizontally all around the structure for the siding (probably cutting 45 degree angles so they lap over one another).  I know when you do this with a roof you lose a lot of structural support, and laying plywood first is probably recommended but the fence board was meant to save some bucks.  I suppose I could compensate by adding corner bracing on all corners to stiffen up the structure, would that be enough? 

I do not have access to post from work, so I will try to remember to take some screenshots of what I have already and post them tomorrow to give you a better idea of what I mean.  I want to put some clear plastic ~~~~~ type paneling on the roof for light during the day.  That was fun to create in Sketchup... but I managed.

[Redoverfarm]

Most that I have seen and help build utilize a platform which is about 1' wider than the pit or sit on skids to move later on.  If the pit is dug fairly clean walled you do not want to line it with anything.  Let the earth perc the contents.  Given that the structure is 1' wider than the pit there is little chance that it will collapse unless it is on sandy soil.  Don't forget a vent stack from the pit to above the roof line.

Here is a search of various styles and designs.

https://www.google.com/search?sourceid=navclient&aq=&oq=out+house+plans&ie=UTF-8&rlz=1T4TSNA_enUS401US438&q=out+house+plans&gs_l=hp..0.0l2j0i22i10i30l2j0i22i30.0.0.0.32911...........0.ku5HK4xfLHo

[MountainDon]

Perhaps there is something useful in this older thread here.   

[hpinson]

And this may be helpful too:

http://countryplans.com/smf/index.php?topic=10231.50

State blessed outhouse build follows over a few pages.

[Adam Roby]

Thanks for all the links, there is a ton of information in there.

hpinson, your design is almost identical to how I wanted to do the footing, so I'll consider this a feasible plan.
Did you use some laser guided cutting tool to do your pit?  I've never seen such a perfectly cut hole like that!

I want to put in some wood in the pit, but more like a pallet layout where you'd have one piece then a space.  Partially because the top part of that would be part of my mold for the footing... at least that was the idea.  In practice that may never happen.

My buddy up the street just purchased one of those digging machines that have wheels but no propulsion...
Something like this but a bit bigger with 4 wheels  (6' digging capacity)


I will probably borrow that for my hole (will be much messier).  He now has 4 bulldozers, 2 loaders, 2 tractors, and this mini excavator.  All of them are in not so good shape (rust in tanks, needing grease, paint, hoses, etc.) so we will likely spend the first part of summer working on the machines, but once they are all functional then the land will be a piece of cake to fix up how I want.

[hpinson]

Three years now, and its working well.

I agree with Redoverfarm that a fully lined the pit would retard percolation.   I had a County requirement for a fully lined pit, but I don't think they are not basing this on any best practice.  It's so dry where I am that there is effectively no percolation. The turds just dry up and turn to dust in the pit.  The idea behind lining is to prevent a cave in, so the lining should really depend on the integrity of the walls of the pit.  I think some lining, with significant space between the slats, would be ideal if your soil supports that.

It's such a small hole, you may have better results digging it by hand.  For us it was about six hours of work to dig the pit.  I guess it depends on conditions though.  The sharp lines were obtained through use of a shovel and the quartz sand allowed it.

Reminds me of a scene in Lonesome Dove where Newt is digging an outhouse hole.

[SouthernTier]

My experience may or may not be of help.  I am in western NY, so probably not too different conditions from you.

Here is an account or me building my outhouse: http://countryplans.com/smf/index.php?topic=8853.msg114386#msg114386

For the foundation, I just did two courses of 8"x 8"x 16" concrete blocks.  After laying and mortaring them, I filled the holes with mortar as well.  Plus I drove 2' long rebars into the ground through the holes.

This is 5 years ago and no problems whatsoever.  The shed I also built at my property has deep sonotube foundations and so it doesn't frost heave, but I have a "floating" step outside the shed and the last two winters, this rose uo 4" - 5" above it's summer time elevation (in relation to the non-moving shed), so I know frost heave is working as advertised in my area.  But my outhouse has shown no signs of damage. I am assuming it rose up and down a few inches over the winter, but no impacts structurally at all.

My soil is stiff so no problems with keeping the walls from caving in.  Big problems digging it by hand (took the whole summer, a little bit at a time, hand digging with a trowel since the 3'x4' opening was too narrow to get a spade or pick in.

[Adam Roby]

I am resurrecting this thread because I am starting the build soon (at home) and will assemble on site once the ground is defrosted enough to dig.

I am wondering about venting.  Typically people recommend using ABS pipe, going from the pit to the roof, and as the black pipe heats it helps to convect the odor from the pit to the outside.  I was thinking, to help keep water out, I would curve the end (2x 45 degrees) and add a solar powered fan to the end of the pipe.

(my 3d skills are not great, but I think you'll get the idea)




The fan in question is a measly $3 with free shipping, so I might just order 2 or 3 to replace them as they fail.
http://www.ebay.ca/itm/New-energy-saving-Clip-on-Solar-Cell-Fan-Sun-Power-energy-Panel-Cooling-Black-SC-/221911312365?hash=item33aaf1e7ed:g:VrkAAOSw~bFWGzL~

It would mean only venting during the sunlight hours... which is mostly when it would be used... and I'd assume convection would still play a role even if the vent was pointing down.

Thoughts?

[hpinson]

Sure.

I think a little solar fan is fine as it will only encourage air circulation, which is good, especially in cooler temperatures.  I was considering doing just that, but never got to it.  I just put a screen over the top of the  stack, but there's no trees around so nothing really to clog it.  Where I am, in summer the stack heats up so much in the day time, that it needs no encouragement to vent. I used black pipe to encourage the stack heating.  You can actually feel the downdraft at the head.  Just make sure the bottom of the stack sits lower than ground level in the pit.

Some water getting in is not necessarily a bad thing as it will help with decomposition.  Where I am, I encourage the water lest everything just desiccate.  I actually pour a few buckets of water in, with some dissolved brewers yeast, towards the end of the summer.  I don't know if it really helps, but there has been very little buildup overall over four years now.

[rick91351]

There were some very good plans from a couple states Dept of Ag for building a outhouse....  A lot of States Department of Health have some excellent papers on pit toilets.  Some like to use slacked lime or calcium hydroxide - works well controlling flies and odors....

http://www.ehow.com/how_5915471_use-lime-outhouse.html



   

[MountainDon]

Sun-Mar has a vent that prevents rain water entry yet provides a direct up path for the air flow. Here's a photo of ours...



The grey pipe is thinwall 4" PVC. The black pipe is larger. The adapter piece is not solid, it is a mostly open web. Sorry no photos of the piece.

Most rain falls with a slight slant. Any drops that angle in a strike the inside wall of the black section runs down the inside of the black pipe and out the open spaces in the adapter. Only a rain drop that falls near perfectly vertical stands a chance of actually getting inside the grey pipe . It seems to work very well.  No fan needed.

I think you could rig up something using 4 and 6 inch pipe and some skinny bolts and spacers.  Maybe a length of 6 inch galvanized heating duct over 4 inch pvc?

[Adam Roby]

Thanks for the ideas...  I ordered two of those small fans since they were pretty cheap and I could probably use them for some other project if I don't use them on this one.

I may submit some plans for commentary in the coming few days / weeks.  I figured buying the wood in small quantities at a time, and working them in different sittings would make the cost not as noticeable and the work more enjoyable.  Hopefully I can easily transport an entire wall section or floor in one piece.  Planning on making it a bit bigger, 5'x6', to accommodate also being able to store a few tools and stuff in there when I am not on the land (shovels, and maybe gas cans and such).  Not sure how well that will work out, but its a bit of a pain to haul stuff back and forth every time I go.

[OlJarhead]

We used PT 2x's and 4's to make the 'cage' for the hole (shoring) and then built a wood platform on top of that for the floor


The thing with Outhouses is that they eventually fill up so if you can move them it's better than having to build a new one.

[Adam Roby]

...The thing with Outhouses is that they eventually fill up so if you can move them it's better than having to build a new one...

Yeah, that one has me wondering...  I think I could pull mine off the mini-foundation I am planning... or I could just remove the floor, fill up the remaining space with dirt and close it up to use as a shed... by then I should have either a trailer or cabin in place.  99% of the time I will be alone, sometimes with my daughter, and maybe once or twice per year with my wife.  As it is, I doubt I would get up there very often, at best 1 day every other weekend, during the summer months only.  So... 8 times per year?  Kind of pathetic...  but at that rate it'll take me 20+ years to fill up the hole.  Buddy of mine wants to also build, but with a door in the back and using a kind of bucket inside.  Just empty the bucket now and then.... well, not really a bucket, like a 50 gallon drum cut at the seat height.  I'd rather it fall 6-8 feet from my butt than have it linger that closely. 

[Don_P]

That was one of the reasons for a deep pit, a hookworm has to find a new host within several feet. We also swept around under the seat good before perching, black widows.