Building an outhouse / outdoor toilet – Part 1

If you have a cabin or a small house in a remote location, you are by all means already familiar with the issue of disposing human waste from defecation and urination. If you still haven’t built your cabin, you might want to delay it a bit and first build an outdoor toilet, which will provide you with more comfort while building you cabin. This article provides information on how to build an outdoor toilet (also referred as outhouse or latrine),  in conditions where there is no sewage and building a septic system is not feasible.

This design consists of an underground leak-proof ventilated pit which holds the waste and the outhouse itself which can also be fitted to be a summer bath. The pit can be emptied by ether a specialized waste disposal vehicle or in extraordinary situations – by buckets. The first part of the article concentrates on the building of the underground part of the outhouse and this can be done by following the instructions below:

Digging the pit

Digging the pit

The first obvious step (after the planning) is to start digging the pit. While this can be achieved much easier with some specialized equipment, a simple shovel will also do the trick. Choose the size of the pit carefully and keep in mind the number of people that will use the outhouse and how long it will take to fill it’s capacity.

Cover the bottom with a thin layer of gravel

Cover the bottom with a thin layer of gravel

Once done with the digging, cover the bottom of the pit with a thin layer of gravel (maybe not more than 3 or 4 cm). This will prevent the concrete mixing with the soil.

Placing the framework

Placing the framework

Next you will need to put some kind of framework which will harden the concrete and make it stronger. Having in mind that there will be no great forces acting on this concrete, as it will serve as the bottom of the pit, you can skip this step. If you decide to put the framework though, keep in mind that it needs to be elevated from the gravel and it should be approximately in the middle of the layer of concrete that you are about to pour.

Pouring the concrete

Pouring the concrete

When pouring the concrete, try to do that as fast as possible. If you are not able to make the whole amount of concrete and pour it at once, you might need to go down and level the already poured concrete before it hardens. Keep in mind that the poured concrete will start hardening in about an hour and after that it will be increasingly difficult to distribute it or level it. The concrete that we used was made from 1 part cement, 1 part sand and 2 parts gravel. You need to stir all of the components well, before adding the water, which should be not more than 1/2 parts. While this mixture can be a little bit stronger than needed for our purpose, we chose to be safe than sorry.

Making an elevated belt of concrete

Making an elevated belt of concrete

The concrete floor of the pit needs to be leveled. If you fail to do that right from the first time and you start building the walls from bricks, then the walls will not go straight and they might collapse at some time. In order to prevent that. you need to build a well leveled concrete belt, on top of which you will build the walls of the pit. To get that right, you need to make a wooden casing that will hold the concrete belt and you need to level the top edge of casing itself. That way, when you start pouring the concrete, you will pour it to the edge of the casing and you will be certain that the belt itself will be leveled.

Building the brick walls

Building the brick walls

Next you need to build the walls. The type of bricks we used are not the quite suitable for our purpose because we want the pit to be sealed and these bricks let water go through them. However we had them laying around and we decided to use them and then seal the pit with some water proof cement. We used 1 part cement, 2 parts sand and 1/2 part water to make the mixture that will hold the bricks together. You might need to put a little bit thicker layer of the mixture so that when you put a brick on top of it, you have some space to level it. This is usually done by tapping the higher edges of the brick with a rubber hammer, until it gets leveled.

Applying the water blocking cement

Applying the water blocking cement

As mentioned above, because of the type of bricks that we had at hand, we needed to seal the pit with a water blocking cement. This particular cement that we got, was applied like a paint with a brush and 3 layers or 3 mm from it are enough to make this pit water proof. Even if small holes remain, they will be quickly sealed by the waste itself. We also applied it on the floor, again just to be on the safe side.

The frameworks for the top of the pit

The frameworks for the top of the pit

Next you need to build the wooden framework, on top of which you will pour the concrete that will form the top of the pit. We did it by using a joist cut in two and we put the thinner boards on top. Keep in mind that they will hold significant weight, so you might want to be careful and opt for thicker boards. The square whole that you see will be covered by a steel lid with a thick pipe going through it. The pipe will be used for ventilation and to grant access to the pit for the waste disposal vehicle, while still leaving an option for the pit to be emptied by a bucket. The longer rectangular opening will be where the toilet seat and the other ventilation opening will be located. Before pouring the top, don’t forget to put the iron framework on top of the boards. Again it has to be elevated so it stays in the middle of the concrete layer. This time you will need much thicker iron rods to make the framework, compared to what is used on the bottom of the pit. This is because the bottom of the pit is supported by the ground itself, while here the concrete will hang over an open space. We used o.8 cm thick rods to build the framework and we welded them together for greater strength.

Making the service hatch

Making the service hatch

You need to elevate the hatch from the surface of the pit top, so rain water doesn’t soak through the soil and enter the pit. The surface of the concrete here needs to be very smooth and leveled so that there are no gaps when the metal cover is put on top of it.

The last effort

The last effort

The last step from the underground part of the outhouse will be to elevate this opening to the surface level. Don’t forget to make a hole in the wood casing and to put a plastic pipe through it, before you pour the concrete. This pipe will be the ventilation pipe, which will suck the gases out of the pit. While we could have avoided that by raising the top of the pit to the surface level, we wanted to build it in a way that the service hatch is not visible and therefore it needed to stay underground. We also wanted to have enough soil on top of the concrete so we can plant some flowers or bushes on top.

In the next part we will cover the building of the outhouse itself and we will also cover what different uses it might have.

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