--- title: Josam 21500-IRMA-6 Large Sump, Wide Flange, Perforated SS Extension description: Find a diagram and detailed description of the Josam 21500-IRMA-6 Series large sump with wide flange and perforated stainless steel extension. --- Search our inventory of drains, drain parts, safety and roofing equipment, and accessories. [Shop Now](https://hy-techroof.com/products/). - [ About ](https://www.hy-techroof.com/about-hy-tech/) - [ Contact ](https://www.hy-techroof.com/contact-hy-tech/) - - [![Hy-Tech Roof Products](https://resources.hy-techroof.com/hubfs/Logos/Hy-Tech%20Logo_rgb_maroon_480.png) ](https://www.hy-techroof.com) [**](https://www.hy-techroof.com/login.php) [**](https://www.hy-techroof.com/cart.php) ** ** [![Hy-Tech Roof Products](https://resources.hy-techroof.com/hubfs/Logos/Hy-Tech%20Logo_rgb_maroon_480.png) ](https://www.hy-techroof.com) [**](https://www.hy-techroof.com/cart.php) - - # Josam 21500-IRMA-6 Large Sump, Wide Flange, Perforated SS Extension *Dimensional data is subject to manufacturing tolerances and change without notice.*  #### *[Download Specification PDF](https://resources.hy-techroof.com/hubfs/Manuals%20+%20Brochures/josam%20s06_21500.pdf) * **Specifications: **The Josam 21500-IRMA-6 Series is a coated cast-iron roof drain with a large polypropylene locking dome, dome support ring and perforated stainless steel extension filter. Includes a WEJLOC® non-puncturing clamp ring and large sump with an extra-wide roof flange and bottom inside caulk connection outlet. **Application:** Used on roof systems where an "insulated membrane assembly"—also known as an "inverted membrane assembly"—is specified. Insulation is installed on top of a waterproof membrane, and then gravel ballast is applied over the insulation. The drain is furnished with a perforated stainless steel extension made to the specified height of the insulation combined with the depth of the ballast. A large slotted dome ensures maximum free area for quick rainwater drainage while protecting the drain sump and connected piping from debris. Its WEJLOC® compression-flashing clamp holds the membrane or flashing securely to the drain body. An extra-wide deck flange provides positive support and a large bonding survace for liquid applied membranes. | **Type No.** | **Pipe Size (in.)** | **Weight (lbs.)** | | --- | --- | --- | | 21502-IRMA-6 | 2 | 77 | | 21503-IRMA-6 | 3 | 78 | | 21504-IRMA-6 | 4 | 79 | | 21505-IRMA-6 | 5 | 80 | | 21506-IRMA-6 | 6 | 81 |   [![Find and Buy Josam Roof Drains](https://no-cache.hubspot.com/cta/default/10783/112c363c-f175-47e1-8f39-ff6234a79ff6.png)](https://cta-redirect.hubspot.com/cta/redirect/10783/112c363c-f175-47e1-8f39-ff6234a79ff6) ## Outlet Types - Inside Caulk Outlet (-X) ## Options - Secondary Flashing Clamp (use with -AE only) (-4) - [Drains](https://www.hy-techroof.com/products/drains/) - [Zurn](https://www.hy-techroof.com/manufacturers/zurn/) - [Smith](https://www.hy-techroof.com/manufacturers/j-r-smith/) - [Josam](https://www.hy-techroof.com/manufacturers/josam/) - [Wade](https://www.hy-techroof.com/manufacturers/wade/) - [Marathon](https://www.hy-techroof.com/manufacturers/marathon/) - [Olympic](https://www.hy-techroof.com/manufacturers/olympic/) - [Equipment](https://www.hy-techroof.com/products/equipment) - [Garlock](https://www.hy-techroof.com/manufacturers/garlock/) - [Leister](https://www.hy-techroof.com/manufacturers/leister/) - [All Seasons / Grizzly](https://www.hy-techroof.com/manufacturers/all-seasons-equipment/) - [Hennes-Johnson](https://www.hy-techroof.com/manufacturers/hennes-johnson/) - [Gator](https://www.hy-techroof.com/manufacturers/gator-roofing-equipment/) - [Roofmaster](https://www.hy-techroof.com/manufacturers/roofmaster-products-company/) - [Safety](https://www.hy-techroof.com/products/safety) - [Leading Edge](https://www.hy-techroof.com/manufacturers/leading-edge-safety/) - [Tie Down Manufacturing Ingenuity](https://www.hy-techroof.com/manufacturers/tie-down-manufacturing-ingenuity/) - [Malta Dynamics](https://www.hy-techroof.com/manufacturers/malta-dynamics/) - [Resources](https://resources.hy-techroof.com) - [Account](https://www.hy-techroof.com/login.php) - [The Drain Wizard](https://resources.hy-techroof.com/ask-the-drain-wizard) - [FAQ](https://resources.hy-techroof.com/faq) - [Blog](https://resources.hy-techroof.com/blog) - [Roof Drain Specs](https://resources.hy-techroof.com/roof-drain-specs-and-diagrams) - [Video Library](https://resources.hy-techroof.com/video-library) - [About](https://www.hy-techroof.com/about-hy-tech/) - [Contact Us](https://www.hy-techroof.com/contact-hy-tech/) - [About Hy-Tech](https://www.hy-techroof.com/about-hy-tech/) - [Service and Repairs](https://www.hy-techroof.com/service-and-repairs/) [800-635-0384](tel:8006350384) **Hy-Tech Products **10035 Broadview Road, Broadview Heights, OH 44147 [info@hy-techroof.com](mailto:info@hy-techroof.com) [800-635-0384](tel:8006350384) **Hy-Tech Products **10035 Broadview Road, Broadview Heights, OH 44147 [info@hy-techroof.com](mailto:info@hy-techroof.com) © 2026 Hy-Tech Products, Inc. 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