Low-slope and flat roof sections

Normal function

A membrane creates a continuous water-shedding surface where shingles may not be appropriate. Drainage, seams, edge terminations, and penetrations are critical.

What a homeowner may notice

• Ponding after reasonable drainage time, open seams, blisters, punctures, shrinking membrane, loose edge metal, or failed penetrations.
• Shingles installed on a section too low for the product or detail.
• Water at porch/addition tie-ins, parapets, scuppers, or roof drains.
• Membrane surface cracking, exposed reinforcement, or repeated patching.

Professional inspection

Measure slope and roof area, map drains/scuppers, inspect seams and terminations, check substrate movement, ponding, penetrations, and adjacent steep-slope transitions. Never assume a shingle repair will solve a membrane defect.

Repair or replacement path

Use the same or compatible membrane system and manufacturer-approved primer, tape, adhesive, or heat-weld method. Correct drainage and edge details instead of repeatedly patching a symptom.

Typical materials and equipment

EPDM/TPO/modified bitumen patch material, seam tape or adhesive, primer, rollers, flashing, termination bars, compatible fasteners, and drainage components.

When to act

Ponding and open seams should be evaluated before repeated storms or freeze/thaw cycles worsen the assembly.

What moves the price

Membrane type, wet substrate, ponding, seam length, edge termination, roof drains, access, insulation, and code/permit scope.