Yes, our yurts are waterproof. The main source of leakage in traditional yurts is through the crown/skylight.
Our yurts are designed to be waterproof even without covering the crown/skylight with a flap. We do not cover the crown/skylight with cheap vinyl to prevent water from coming through the crown/skylight, as other suppliers do. This also blocks air circulation through the skylight. Instead, our crown/skylight is fully covered with clear plexiglass and has openings for air circulation and smoke pipe while ensuring it is still waterproof.
You can use the flap crown/skylight cover included in our yurt to block sunlight to prevent the yurt from becoming too hot, but not for waterproofing.