How to Make a Below-Ground Home Waterproof

Select a site suited for the construction of a below-ground home since an inappropriate location will negate all efforts to waterproof the structure. Choose a slightly sloped area from which water will naturally drain away. Avoid building too close to the upper reaches of the water table or in boggy areas where water collects after rainfall.

Install drainage along the base of the foundation before construction begins and along the roof slope once construction is nearly completed. Consult with a contractor to determine the best type of drainage system given the composition of the soil, seasonal precipitation and the construction materials.

Select from commonly used types of structural waterproofing, such as vulcanized rubber or plastic sheeting, spray-on bentonite clay, rubberized asphalt, pitch-enhanced liquid membrane or liquid polyurethane. Consult with a contractor to determine which type of waterproofing is suitable for the climate, volume of precipitation and building materials.

Apply the chosen waterproofing component above the concrete and steel frame of the structure after installing the interior insulation. Perform this task under the guidance of your contractor, who will show you exactly how to attach and seal the waterproofing for maximum effectiveness.

Seal around all windows, skylights and ventilation outputs with self-adhesive, rubberized asphalt membrane to eliminate potential moisture seepage. Apply the membrane only after the proper flashing is installed. Again, defer to the advice of your contractor when sealing the structure since he will be able to guide the process for the best results.