The NDS Dura Slope Channel Drain is a high-performance, modular channel drain with a built-in slope, designed to handle heavy water flow and deeper installations. The same system is searched for as both the Dura Slope channel drain and trench drain; it uses 6-inch-wide HDPE channel sections with a built-in 0.7% slope, stepped invert depths, and a choice of traffic-rated grates for demanding driveways, commercial sites, and loading areas.

The NDS Dura Slope Channel Drain modular sloped system.

What is the Dura Slope Channel Drain?

Dura Slope is NDS's modular, high-capacity drainage line, molded from high-density polyethylene (HDPE) with UV inhibitors. Its hallmark is the built-in slope: each section carries a 0.7% slope, and sections step down through a series of invert depths so water accelerates toward the outlet without the installer having to precisely grade the trench bottom. Neutral (no-slope) sections are also available to set transitions and outlets. The 6-inch-wide channels snap together with tongue-and-groove joints and alignment tabs, and accept a wide range of grate materials and styles.

Why choose Dura Slope

• Built-in 0.7% slope: stepped invert depths create continuous fall toward the outlet on long runs, without pitching the trench.
• High capacity and depth: 6-inch-wide channels, with overall section depths from about 5.8 in up to about 13.5 in as the invert steps down, move heavy runoff.
• Grate options for any duty: ductile iron grates are rated for H-20 vehicular loads with proper encasement; stainless steel, plastic, and decorative, slot-top, and perforated styles are also available.
• Lightweight and modular: HDPE sections are far lighter than concrete, cut freight cost, and combine to reach the depth and length a site needs.

The narrower, lighter-duty NDS Spee-D channel.

Where the Dura Slope is used

Dura Slope suits driveways, parking areas, warehouses, loading docks, pool decks, wash-down areas, and other flat, hard-surfaced sites that see heavy flow, deep runs, or vehicle traffic. For a narrower, lighter-duty run, the NDS Spee-D Channel (4-3/4 in. wide) is the alternative — a lighter-duty channel, rated to about Class C, where you set the fall yourself during installation. Choose Dura Slope when depth, built-in slope, and H-20-capable grates all matter.

Choosing the Dura Slope

Choose Dura Slope for deep, sloped, heavy-duty runs. The Channel and Trench Drain Selector can confirm whether Dura Slope or another NDS line fits your flow and depth.

Installation: slope, base, and concrete surround

The Dura Slope uses its built-in stepped slope, set on a concrete bed inside a concrete surround.

The Dura Slope system installs a little differently from the plastic channel lines because the slope is built into the channel sections themselves, but it still relies on a concrete bed and full concrete surround.

1. Plan the run and invert depths. Dura Slope sections step down through a series of invert depths, so the channel gains depth toward the outlet. Lay out the sections in order so the built-in fall runs the right direction; use neutral (no-slope) sections where you need a constant depth, such as at the outlet.
2. Excavate to depth. Because Dura Slope is deeper than the plastic lines (overall section depths range from about 5.8 in on the shallowest section up to about 13.5 in on the deepest as the invert steps down), dig the trench deep and wide enough for the deepest section plus a concrete bed and surround.
3. Use the built-in slope. The sections carry a built-in 0.7 percent slope, so you generally do not need to pitch the trench bottom the way you would with a neutral channel; the stepped inverts create the fall. Still confirm the run drains to the outlet.
4. Bed and connect. Set the sections on a concrete bed, join them in order with the tongue-and-groove joints, and connect the outlet to the underground drain pipe.
5. Pour the concrete surround. Encase the channel in concrete up both sides. Dura Slope's ductile iron grates suit heavy and vehicular traffic, so the surround must be sized for the expected loading per the project drawings.
6. Finish flush. Bring the surface level with the grate so water enters cleanly.

Getting the slope right

Slope is the single most important detail. Without fall toward the outlet, water sits in the channel instead of draining. For straight, neutral channel lines, grade the trench bottom to about 0.5 to 1 percent toward the outlet. The Dura Slope line removes this step by building a 0.7 percent slope into its stepped sections. Either way, confirm positive drainage with a level before the concrete sets, because corrections are difficult afterward.

The concrete surround

A channel drain is only as stable as the concrete around it. The channel should sit on a concrete bed and be encased on both sides so it cannot shift or float, with the grate finishing flush with the surrounding surface. The depth and strength of that surround should match the traffic: light foot traffic on a patio needs far less than a driveway or a commercial area that sees vehicles, where a thicker, reinforced surround and a load-rated grate are required. Always follow the project drawings or manufacturer guidance for the bedding and surround dimensions.