Before beginning repairs to your rubber roof, you'll need to clean the area. More critically, you need to remove the grime from the seam where you'll perform the repairs. Apply a solvent-based cleaning solution, using a rag on seams in need of repair. You can purchase the solution at a hardware store, but a roofing supply store has a variety of products from which to choose.
EPDM – Ethylene Propylene Diene Monomer – rubber roofs require EPDM adhesive on both sides of the seam, using a paintbrush. Apply the adhesive 6 to 8 inches deep into the seam and a significant amount to the corners of the seams you pulled apart.
To ensure your seams don’t pull apart prematurely, secure them with seam tape. You need to use a silicone roller to secure the tape to the seams. Run the roller over the entire area, including a foot on each side of the seams. Use the silicone roller to ensure the tape is tight at the transition from one sheet of rubber to the next.
If your rubber roof has held water in certain areas for extended periods -- pooling -- you may need to repair an entire section of EPDM rubber. This is an unusual occurrence but it does occur. To replace an entire sheet of rubber, you'll need to entirely remove the old sheet, including any adhesives used to seal the original sheet.