Vaulted Toilet Vs. Pit Toilet

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Vaulted toilets and pit toilets are types of outhouse toilets.
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When you don't have access to water or plumbing, the best waste disposal system is an outhouse, which can either be a vaulted toilet or a pit toilet. This was known only too well by the pioneers settling on previously uninhabited land, and it's a fact well understood today by the U.S. Forest Service, which maintains comfort stations in remote parklands nationwide.

Whether it's built to accommodate one person or many, an outhouse is basically a shelter built over a hole in the ground. If the hole is lined with a water-impermeable container, it's known as a vaulted toilet, whereas if it's simply left as is, it's called a pit toilet. Both have their pros and cons.

Simplicity of a Pit Toilet

If you want to make a simple outhouse, start by finding a suitable place and digging a large hole in the ground. Cover this with a wooden bench with an opening, construct a small shelter around it, and you're done. Waste that goes into the pit stays where it is until it decomposes and becomes part of the earth. It's a pretty straightforward approach, but there are a few problems:

  • It smells, but if you assiduously add sawdust after every use, it doesn't smell as bad, and if you install a vent pipe that goes through the roof of the shelter, the odors can almost disappear.
  • If you overuse it and it fills, you have to remove the structure, fill in the hole with dirt and start over again somewhere else.
  • Liquid waste can leach into the groundwater if you dig the pit too close to the water table.

Despite these drawbacks, one of the biggest advantages of a pit toilet is that it's virtually maintenance-free — that is, until it's full.

A Vaulted Toilet Lasts Forever

You can convert a pit toilet to a vaulted toilet simply by digging a pit large enough to accommodate a container to hold the waste. Such containers have been constructed of concrete in the past, but today, most are made of cross-linked polyethylene, a material that won't crack, leak or decompose. A vaulted toilet has the same odor problems as a pit toilet, and this is often addressed with chemicals as well as with venting, but if a vault fills up, you can pump the waste into a truck and haul it away, so you never need to relocate the toilet.

Vaulted toilets are a great permanent waste solution for remote areas, which is why the U.S. Forest Service uses them extensively, but there's one small problem. You need roads to be able to haul away the waste. Vault toilets won't work in remote areas that you can only access on foot; for these places, a pit toilet is the only possibility.

Waste Decomposition vs. Sanitization

Another big difference between pit toilets and vaulted toilets is the way waste gets handled. In a pit toilet, it remains in the pit forever and decomposes, eventually turning to compost. The waste in a vaulted toilet can't seep into the ground, and without access to beneficial bacteria from the soil, it turns into an anaerobic slurry in the vault and can become dangerously unsanitary. When the vault is emptied, it's usually sanitized at the same time with deodorizing chemicals that, in their way, smell as bad as the waste. If you want to build an ecological toilet, build a pit toilet.

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Chris Deziel is a contractor, builder and general fix-it pro who has been active in the construction trades for 40 years. He has degrees in science and humanities and years of teaching experience. An avid craftsman and musician, Deziel began writing on home improvement topics in 2010. He worked as an expert consultant with eHow Now and Pro Referral -- a Home Depot site. A DIYer by nature, Deziel regularly shares tips and tricks for a better home and garden at Hunker.com.

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