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How To Integrate An Exterior Drain Tile Into Your Earth Sheltered Home

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Earth sheltered homes provide various benefits for their owners. Not only do they look aesthetically pleasing due to their integration with the land around them, but using an earth berm against your home can save on building materials and keep the temperature in your home more consistent throughout the year. Earth sheltered houses present various architectural challenges due to the heavy load of earth pressing against walls and roofs. However, an exterior drain tile can help alleviate some of the problems you encounter. 

Using a Drain Tile to Reduce Weight Against Your Structure 

One of the major issues bermed and buried homes face is the immense pressure that large amounts of earth can place on your walls or roof. Most DIY home builders fix this problem by slightly leaning their wall into the earth, turning their interior walls into large buttresses that create a counter-pressure against the walls, or designing a slight curve into their exterior wall. Although these are all great ways to create a safe structure, you will also want to consider how you can reduce the overall weight pressing against your home. 

Wet earth weighs significantly more than dry earth. Using a drain tile to direct the flow of water away from your home can decrease the weight of the earth that presses against this. To achieve this benefit, you will want to install your drain a bit further away from your home than usual, about six feet. You may also decide to use a lighter weight rock in your drain. While most exterior drain tiles utilize heavier gravels, you can choose to use volcanic perlite or another light weight rock. However, keep in mind that the majority of the benefit will come from keeping the earth dry, so a heavier stone should not make that much of a difference.  

Integrating a Drain Tile Into Your Tiered Garden 

When most people think about installing an external drain tile, they are usually concerned with keeping water away from their foundation or basement. Little thought, besides installing a proper sump system, goes into where the water drains. However, if you are building an earth sheltered home into a hill, you can use your drain tile to funnel water into a tiered garden. This follows the permaculture principles of working with the layout of your land to optimize both growing areas and human living space. 

A properly tiered garden, with plants that need the most water dug into basins and less water-hungry plants placed further up, can utilize the water that would eat away at your foundation and walls while adding beauty to your property. 

Using a Drain Tile to Gain Control Over Your Living Roof 

If your house is fully buried and has a living roof, you will want to have control over the weight of the soil above you as well as how much water the plants receive. Most living roofs utilize plants that need very little moisture in order to reduce the weight of the roof. An exterior drain tile installed close to your home can divert water away from your roof, preventing the soil from washing away while the plants take root and protecting your roofing materials. 

If your house is buried into the side of a hill, you may want a slightly wider drain than usual, perhaps 2-3 feet wide, and you will want the gravel to extend all of the way to the surface instead of being buried in soil. This will prevent water from running over your drain, onto your home. 

While most earth sheltered home builders concentrate on strengthening their home from the inside, you should consider the features that will integrate your home into the surroundings and protect it from the outside. A proper drain tile is one such feature that you should not overlook. 

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