Building an Outhouse for Extreme Weather — What Do You Need?

Water-Resistant Design

When building an outhouse for harsh weather, it’s essential to focus on a water-resistant design. This includes installing a 3-ply roof with a waterproof underlayment, such as EPDM (ethylene propylene diene monomer) rubber, and a durable roofing material like corrugated metal or asphalt shingles. The roof should also be slightly pitched to allow water to run off. Aim for a minimum roof slope of 3:12, with a 12-inch overhang on all sides to prevent water from seeping under the edges.

Durable Materials and Construction

Choose durable materials for the outhouse’s walls and floor, such as 2x6 or 2x8 pressure-treated lumber for the frame, and 1/2-inch or 3/4-inch plywood for the walls and floor. Use galvanized or stainless steel fasteners to resist corrosion, and apply a waterproof sealant around all joints and edges. Consider adding insulation to the walls and floor to reduce heat transfer and minimize moisture accumulation.

Anchoring and Foundation

A secure anchoring system is crucial to prevent the outhouse from being lifted or shifted by strong winds. Dig a foundation that’s 12 inches deep and 18 inches wide, using a mix of gravel and sand for drainage. Pour a concrete slab within the foundation, and install anchor bolts (at least 2 per corner) that can withstand the expected wind loads. Secure the outhouse to the foundation using heavy-duty lag screws or anchor straps. For areas with high snow loads, consider adding a snow load-rated roof anchor system.