Replacing a roof is an opportunity to correct weaknesses in the entire assembly rather than simply cover them with new material.
When Replacement Becomes the Better Decision
Replacement may be appropriate when deterioration is widespread, repairs are recurring, roofing has lost integrity across large areas, decking problems are substantial, the roof is being converted to a different system, or the owner needs a more predictable long-term solution.
What a Replacement Scope Should Address
A complete scope should define tear-off, disposal, decking evaluation, underlayment or membrane, flashing, penetrations, valleys, edges, ventilation where applicable, drainage details, cleanup and how unforeseen substrate damage will be handled.
Choosing the Roofing System
Steep-slope homes commonly use asphalt shingles, metal or selected cedar systems. Low-slope areas may require membrane roofing. Commercial and multifamily roofs should be matched to roof design, rooftop traffic, equipment, drainage, substrate and maintenance expectations.
Decking and Hidden Conditions
The condition of roof sheathing is not always visible until existing roofing is removed. The proposal should explain how damaged decking is documented, priced and replaced if discovered — normally through a written change order, a term the Contractors Glossary explains for Washington projects.
Permits
Permit requirements vary by jurisdiction and project type. Seattle’s rules differ between detached one- and two-family homes and many commercial or multifamily reroof projects. Nearby cities can apply different requirements. See permit requirements.
Planning the Project
For occupied homes and buildings, staging and weather protection matter. Materials should be protected, exposed areas managed, debris controlled and the building left watertight as work progresses.