Fecha de publicación: 12/08/2022 Fuente: WIPO "hemp" The utility model discloses a drainage ditch suitable for drainage of antique sloping roofs and between adjacent antique sloping roofs. The archaized pitched roof comprises a reinforced concrete roof panel, a third cement mortar leveling layer, a polyurethane waterproof coating vapor barrier layer, a third heat preservation layer, a third waterproof layer, a first cement mortar protection layer, a second cement mortar layer, a second hemp knife horizontal slurry layer and a second tile roof layer which are sequentially arranged from bottom to top; drainage ditches are arranged between the lower edges of the antique sloping roofs and the wall bodies higher than the lower edges of the antique sloping roofs, between the adjacent antique sloping roofs and between the adjacent antique sloping roofs, and each drainage ditch comprises a water retaining arch arranged on the antique inclined cornice or the antique sloping roof and a third water drainage pipe arranged on the water retaining arch. Through joint cooperation of the fourth additional waterproof layer and the fifth waterproof layer and joint cooperation of the water drainage pipe, the roof drainage performance and the eave gutter waterproof performance are improved, the waterproof construction requirement is met, and the waterproof structure is suitable for pseudo-classic building commercial street area construction.