Basic purpose of this article is to analysis and discuss on Flat Roof Construction Errors to Avoid. Flat roof is used for many different types of architecture. Most commonly seen on warehouses as well as large businesses, many homes also use this roofing. However, you may encounter ventilation and draining issues when the roof is not fitted and maintained properly. Here focus on Ventilation Issues, Improper Drainage, Improper Roof Coatings and Poor Flashing.