Which of the following roof coverings must be removed before installing new roof coverings?

The roof covering that must be removed before installing new roof coverings is wood shakes. This is primarily due to several factors, including the potential for moisture retention and decay beneath the existing wood shakes. Wood shake roofs can trap water, which may lead to issues like mold or rot. If new roofing materials are installed over them, it could exacerbate these problems by trapping moisture beneath the new layer, ultimately compromising the integrity of the roofing system.

Additionally, local building codes often require the removal of existing wood shake roofs before new installations to ensure proper ventilation and to adhere to fire safety standards, as wood shakes can be more combustible than other materials. This combination of health, safety, and structural integrity emphasizes the importance of removing wood shakes prior to adding new roofing layers.