What term describes the addition of a new roof membrane over a significant portion of an existing roof assembly?

The term that describes the addition of a new roof membrane over a significant portion of an existing roof assembly is "re-cover." This process involves placing a new layer of roofing material over an existing roof, provided that the existing structure can support the additional weight and the underlying roofing is in relatively good condition. Re-covering is often a more economical and time-saving alternative to complete removal and replacement of the roof.

This method is commonly used when the existing roof has no major damage, and it extends the roof's lifespan while also improving its performance. Re-covering can be particularly beneficial because it minimizes labor and landfill waste, as old materials do not need to be removed and disposed of prior to installation of the new membrane.

Re-roofing, on the other hand, typically refers to the complete removal of the existing roofing material and the installation of a new roof. Ridge vent and ridge board are terms related to roof ventilation and framing, respectively, and do not pertain to the concept of adding a new membrane over an existing roof.