earthshelter.com Please Use Browser 'Back' Button to Return to FAQs Waterproofing & Insulation Waterproofing and insulation are installed per site requirements. For example, extremely hot or extremely cold regions call for a thicker layer of insulation. Spray on insulation foam is typically used for its effectiveness and ease of application. A sprayed on water sealant is recommended if the insulation chosen is porous. Owners approach waterproofing in a variety of ways. In dryer areas many owners apply the insulation to the shell and then waterproof over the insulation. Both owner examples on this page show this method. However, more layers are often used for waterproofing an earth sheltered home in areas that get more moisture. In this case: First is typically a layer of liquid asphalt, meant to seal any cracks or pores in the concrete shell, and also act as an adhesive for affixing the second layer. The second layer is a heavy grade waterproof membrane, a thick flexible polyethylene sheeting called EPDM. If choosing this route, we recommend EPDM chemical pond liners made by Firestone for strength and resistance to chemically active soil. Next insulation is applied. The final layer is a sprayed on water sealant. Another Specific Earth Shelter Waterproofing Product Example Case Provided by Dr. Stefan, President of PennKote Limited: Further to our telephone discussion I am pleased to propose following specification for waterproofing a typical earth shelter dome structure of approx 3,000 sq.ft. Waterproofing membrane shall be min 60 mil thick two component cold applied liquid rubber Watertite TPM trowel grade by Pennkote applied over Gunite or Shotcrete surface at the uniform rate of approx 90 sq. ft. per 50lbs unit (see Note 1) using brush, roller trowel or spray (see Note 2). Please refer to Watertite TPM product literature for details. Contact Pennkote for specific details not described in the literature. The proposed use of waterproofing membrane is modified PRMA (protected roof membrane assembly) configuration with sprayed on polyurethane foam applied directly over rubber membrane. Depending on specific circumstances and or usage a composite drainage board or simple protection board may be used over thermal insulation foam or in conjunction with waterproofing membrane prior to earth covering/landscaping, pavers etc. Note1: estimated coverage rate is reduced from 125 sq. ft. /unit (standard) to 90 sq. ft. /unit due to rough surface of the pumped concrete Note2: for spray application Graco GH 833 is recommended. Please visit www.graco.com for details and the Distributor in your area. Note3: visit www.j-drain.com for information on prefabricated drainage composites. Alternatively to Watertite TPM, BlueStuff a single component water based membrane or Aquaban 100 F a flexible reactive cementitious slurry coat by Pennkote could be used or considered for waterproofing depending on geographic location, temperature, etc. Material cost for waterproofing approx 3,000 sq. ft. is approx $2,850- or $.95 sq. ft. taking into consideration reduced coverage over Gunite. Labor cost will be very inexpensive due to simple application of the product. Thank you for your interest. Please contact Mr. Walter Cimini or myself for additional information. Dr. Davor Stefan, P. Eng., President & CEO PennKote Limited www.pennkote.com Tel: (905) 683-6447 Email: davor@pennkote.com Other Waterproofing Products of Note XYPEX Concrete Waterproofing is an admix for new concrete. Xypex becomes an itegral part of the concrete matrix. According to the manufacturer, IMX Technologies, it is self healing and won't break, tear, or puncture like other barriers may. Xypex also solves corrosion issues while increasing concrete durability. Bentonite clay is the alternative that is closest to optimum on the environmental scale. It is naturally occurring and self healing. Grancrete and Hycrete are becoming more readily available. They claim to be environmentally friendly and to reduce or eliminate the need for additional waterproofing. Homeowner waterproofing examples: Brad Glasse provides the following specific advice (and picture) from his own home project: "First, make a drainage trench around the base of the slab that you can place a drain pipe in, sloped to provide drainage. Custom fit the pond liner over the top of the home to provide a water-tight barrier between the insulation and the soil. The liner material on the home continues down into the bottom of the trench. Place appropriate sized perforated drain pipe (covered with a filter sock) into the trench. Next get drain rock (rounded edged rocks only) and place a 12" layer on top of the drain pipe. I found that it's very handy to get a lot of old carpet and place it as a barrier between the rubber and the dirt as the structure is buried. This provides a secondary shield between rocks and the rubber liner. On top of the gravel place sediment filter fabric if you have soil composed of sandy or silty materials. Next, at the bottom and all edges of the line purchase Bentonite and use this to seal the bottom edge, and all side edges on the wing-walls, this can be done as you're burying the home." Another popular waterproofing option is shown below at the Woods' home. The finished shell is covered by yellow polyureathane foam for insulation, which is then covered by the black polyurea for waterproofing. Polyurea is a highly durable material commonly used for lining truck beds. Please Use Browser 'Back' Button to Return to FAQs earthshelter.com