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Zurn Z100 - 15" Diameter Main Roof Drain

Zurn Z100 - 15" Diameter Main Roof Drain

Zurn Z100 - 15" Diameter Main Roof Drain

$780.50


FREE SHIPPING
SKU Z100-3NH

The Zurn Z100 15-inch Main Roof Drain is designed to deliver long-lasting performance, efficient water removal, and dependable protection for commercial, industrial, and institutional roofing systems. Built for heavy-duty applications, it combines rugged construction with adaptable design features to meet a wide range of drainage requirements.

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Product Codes: Z100-2IC, Z100-3IC, Z100-4IC, Z100-5IC, Z100-6IC, Z100-8IC, Z100-2IP, Z100-3IP, Z100-4IP, Z100-5IP, Z100-6IP, Z100-8IP, Z100-2NH, Z100-3NH, Z100-4NH, Z100-5NH, Z100-6NH, Z100-8NH, Z100-2NL, Z100-3NL, Z100-4NL, Z100-5NL, Z100-6NL, Z100-8NL, ZA100-2IC, ZA100-3IC, ZA100-4IC, ZA100-5IC, ZA100-6IC, ZA100-8IC, ZA100-2IP, ZA100-3IP, ZA100-4IP, ZA100-5IP, ZA100-6IP, ZA100-8IP, ZA100-2NH, ZA100-3NH, ZA100-4NH, ZA100-5NH, ZA100-6NH, ZA100-8NH, ZA100-2NL, ZA100-3NL, ZA100-4NL, ZA100-5NL, ZA100-6NL, ZA100-8NL, ZC100-2IC, ZC100-3IC, ZC100-4IC, ZC100-5IC, ZC100-6IC, ZC100-8IC, ZC100-2IP, ZC100-3IP, ZC100-4IP, ZC100-5IP, ZC100-6IP, ZC100-8IP, ZC100-2NH, ZC100-3NH, ZC100-4NH, ZC100-5NH, ZC100-6NH, ZC100-8NH, ZC100-2NL, ZC100-3NL, ZC100-4NL, ZC100-5NL, ZC100-6NL,

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  • Call: (800) 604-5537 for pricing and shipping questions. Shipping estimates shown on the map pertain to this specific product only.
  • Orders typically ship in 1-3 business days. Transit times displayed in the map are listed in business days, and are approximate. The day that the order is shipped is not counted as a transit day.
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Zurn Z100 Roof Drain – Engineered 15″ Diameter Solution for Reliable Roof Drainage

The Zurn Z100 is a 15" diameter primary roof drain with a Dura-Coated cast iron body, a combination membrane flashing clamp / gravel guard, and a low-silhouette Poly-Dome. In plain language: it integrates tightly with roofing membranes, keeps ballast and debris out of the outlet, and moves stormwater off flat or low-slope roofs efficiently.

Heads up: A high-performance, next-generation option exists — Zurn Z100F — designed for boosted flow efficiency. Compare both models at design time to match code, hydraulics, and maintenance goals.
Zurn Z100 15-inch roof drain with membrane clamp and low silhouette poly-dome
Zurn Z100 – 15" Diameter Main Roof Drain

Key Features (Technical → Plain Speak)

  • Dura-Coated Cast Iron Body: Rugged housing that secures to the deck and connects to the storm leader.
  • Clamp / Gravel Guard Combo: Mechanically fastens the membrane and blocks ballast and debris from the drain opening.
  • Low-Silhouette Poly-Dome: High-flow strainer profile minimizes snagging and wind load.
  • 15" Bowl: Large collection area for efficient capture on flat or low-slope roofs.

Best-Fit Applications

Primary drainage on commercial roofs (TPO, EPDM, PVC, mod-bit, BUR) and multifamily/industrial buildings where durability, serviceability, and straightforward membrane integration are essential.

Hydraulics & Sizing Considerations

Size roof drains in accordance with local plumbing code and rainfall intensity data. Pair the Z100’s 15" bowl and low-profile dome with appropriately sized leaders/conductors. Where projects demand elevated flow performance at lower head depths, evaluate the Z100F’s geometry and published flow data.

Options & Accessories You’ll Likely Specify

  • Domes: Standard Poly-Dome or metal alternatives (cast iron, bronze, aluminum) based on impact resistance and maintenance plans.
  • Underdeck Clamp (-C): Stabilizes the drain from the underside — handy for retrofits or variable deck thickness.
  • Extensions: Adjustable (-EA) and Static (-E) for aligning to insulation and finished membrane elevations (can be combined for added height).
  • Internal Water Dams (-W2/-W3/-W4): Raise the weir for controlled ponding strategies — coordinate with the membrane manufacturer’s details and warranty.

Specification Tips

  1. Membrane Coordination: Confirm flashing/clamp details with the roofing system’s requirements.
  2. Elevation Control: Use -EA and/or -E to reach finished heights across tapered insulation zones.
  3. Maintenance Access: Choose a dome that sheds debris readily for your climate and site conditions.
Low-silhouette Zurn Poly-Dome strainer for Z100 roof drain
Low-Silhouette Poly-Dome Strainer

Installation Basics (Step-by-Step)

  1. Prep the opening: Verify deck penetration and slope to drain; clean the area.
  2. Set the drain body: Seat the cast iron bowl; add underdeck clamp (-C) if specified; connect to outlet per code.
  3. Membrane integration: Lay the membrane and secure with the clamp/gravel guard in a progressive star pattern; avoid over-torque.
  4. Cut the opening: Follow the drain’s precast cutting edge to maintain flow performance.
  5. Install the dome: Engage and lock the low-silhouette Poly-Dome (or specified metal dome).
  6. Adjust elevation: Use -EA (and optionally -E) to align to finished surface height.
  7. Flood test & inspect: Confirm watertightness, weir height, and unobstructed path to leaders.
Roof drain installation components including clamp, dome, and extension hardware
Clamp, Dome & Extension Hardware Coordination

Pro Tips for Long-Term Performance

  • Seasonal checks: Inspect domes before/after leaf season and major storms; clear debris promptly.
  • Torque discipline: Tighten clamp hardware evenly; overtightening can damage sealing surfaces.
  • Plan for spares: Keep a replacement dome on hand (plastic or metal) to minimize downtime.
  • Document ponding: Track ponding duration after heavy rainfall; changes may indicate maintenance needs.

Case Study: Warehouse Retrofit Eliminates Ponding

Project: 120,000 sq ft low-slope warehouse with chronic ponding near legacy drains and occasional leak events.
Conditions: Aging BUR with multiple overlays; variable tapered insulation; undersized/dated domes.

Solution: Replace legacy units with Zurn Z100 primary roof drains using underdeck clamps (-C) for stability. Deploy adjustable extensions (-EA) with static extensions (-E) to achieve ~6" elevation in thick tapered areas. Standardize on low-silhouette Poly-Domes for better debris shedding and reduced wind load.

Outcome (12-month review): Post-storm ponding duration dropped from 6–8 hours to < 90 minutes. Service calls tied to roof drainage fell by ~30%, and no clamp-membrane terminations required rework.

Specs Snapshot

  • Model: Zurn Z100 (primary roof drain); next-gen alternative: Z100F.
  • Bowl Diameter: 15" (high collection capacity).
  • Body: Dura-Coated cast iron.
  • Membrane Interface: Combination flashing clamp with gravel guard.
  • Dome: Low-silhouette Poly-Dome (plastic); metal domes available.
  • Common Options: Underdeck clamp (-C), adjustable extension (-EA), static extension (-E), internal water dams (-W2/-W3/-W4).

Zurn Z100 Roof Drain: FAQ

Can I add internal water dams after the drain body is installed?
Yes — -W2, -W3, -W4 water dams can be added post-install, but the existing clamp collar must be removed. Always coordinate with the roof membrane manufacturer/installer for correct detailing and warranty compliance.
Can I use the underdeck clamp (-C) and adjustable extension (-EA) together?
Yes — combining -C with -EA is a common approach to stabilize the drain and align finished elevations across tapered insulation.
How do I achieve ~6" of extension height?
Pair the adjustable extension (-EA) with the static extension (-E) to reach the required elevation.
Are replacement domes available?
Yes — plastic Poly-Dome and metal domes (cast iron, bronze, aluminum) are available as replacements. Choose based on impact resistance and maintenance preferences.
When should I consider the Z100F instead?
When you need enhanced flow efficiency at lower head depths, evaluate the Z100F’s parabolic design and published flow data to meet code and performance targets.
What routine maintenance is recommended?
Inspect seasonally and after major storms; clear debris from the dome and clamp area, verify hardware torque, and confirm the membrane seal under the clamp.