Can a new roof system be installed over an old roof?
Start Fresh – Install a New Roof
Installing a roof system without removing the old system is not recommended.
Water can infiltrate the old system without being apparent, causing interiors leaks. The moisture can also prematurely age your new roof, cause blisters or defects in the new membrane, and cause interior damage. The insulation of the old roof could be deteriorated or moist which will reduce the R-value of your roof system and can increase heating and cooling costs for the facility.