Drainage and perimeter
Identify the questions about drains, overflow paths, ponding, and edge securement.
Commercial roofing
Manage the assembly, the risk, and the building below it.
Commercial roofing decisions connect the deck, air and vapor control, insulation, cover board, membrane, edges, drainage, equipment, maintenance, and operations.
30-second answer
How should a building owner choose a commercial roof system?
Do not compare TPO, EPDM, PVC, modified bitumen, built-up roofing, coatings, and metal as surface materials alone. Attachment, drainage, substrate, insulation, edges, traffic, maintenance, and building use can determine the better fit.
The assembly
Look beneath the membrane.
Most commercial proposals are named after the top layer. The layers beneath it decide attachment, condensation risk, service life, and what the roof costs to own.
- Membrane or covering
The weather-facing layer, and the one nearly every proposal is named after.
- Cover board
Separates membrane from insulation and absorbs traffic, hail, and fastener stress.
- Insulation
Thermal performance, and the layer that sets fastener length, attachment method, and often the slope.
- Air and vapor control
Where condensation risk is won or lost, and a reason two identical membranes can perform differently.
- Structural deck
What everything is attached to, and what limits weight, attachment, and whether a recover is possible at all.
This is a simplified assembly overview, not a prescribed layer stack. Layer selection and position depend on the specified system and building. Drainage and edge securement also need to be addressed in the project scope.
Owner learning path
Condition first, then the system decision.
Start with the assessment guide, then follow recover, drainage, and moisture guidance. Allow about 45 minutes for an initial pass; use the assembly introduction below if these terms are new.
Commission a condition assessment
Define the records, observations, sampling questions, and limitations an owner needs documented.
Evaluate recover versus tear-off
Understand the evidence needed before retaining an existing assembly.
Compare commercial systems
Explore membrane and bituminous systems and the conditions that affect selection.
Compare TPO, EPDM, and PVC
Read the principal membrane tradeoffs and the limits of a material-only comparison.
Define the assembly
Questions a membrane name cannot answer.
Use these guides to prepare an owner scope for a qualified roof consultant or contractor.
Insulation, air, and vapor
Learn which moisture and thermal questions depend on the whole building and its use.
Restoration and coatings
Read about substrate condition, compatibility, and why restoration needs an assessment.
Understand warranty scope
Distinguish product, workmanship, and system coverage and read the actual terms.
Next step
Document the existing roof before writing the replacement scope.
Use the condition-assessment guide to identify the evidence and limitations your owner report should record.
Plan a condition assessment