The NDS Micro Channel Drain is the narrowest NDS channel drain at 1-1/4 inches wide, with the grate integrated into the channel as a single piece, designed to capture light flows around pool and spa decks, concrete and paver patios, and walkways. Its slim profile and integrated grate make it the most discreet option in the NDS lineup for removing surface water before it spreads, stains a deck, or encourages slippery mildew growth.

The NDS Micro Channel Drain with integrated grate.

What is the NDS Micro Channel Drain?

The Micro Channel is the smallest profile NDS offers and part of the NDS Profile Series channel range. At 1-1/4 inches wide with the grate integrated into the channel, it captures light sheet flow almost invisibly, which suits situations where a wider drain would intrude on a finished surface. The recessed grate has openings running parallel to the channel length, so the drain reads as a slim joint line rather than a grille.

It is made of polyvinyl chloride treated with UV inhibitors, and comes in 10 ft lengths in white, sand, and gray, each including a coupling. Sections snap together, and the modular range adds elbows, tees, outlets, and cleanouts to complete a run.

Micro Channel components

• Channel with integrated grate: 10 ft lengths in white, sand, and gray PVC, each supplied with a coupling.
• Elbows and tees: 45 and 90 degree elbows plus tees, all with integrated grate, for turning a run or pulling water in from two directions.
• Outlets: end, side, and bottom outlets that connect to 1-1/4 and 1-1/2 inch Schedule 40 drain pipe, and can be solvent-welded with PVC glue for a watertight connection.
• End plugs and couplings: to close and join runs.
• Cleanouts: added along the run so the channel can be cleared without lifting the surface.

Because the drain and grate are one integrated part, there is no separate grate to fit or fasten, and the modular design makes it straightforward to lay out a run that follows the shape of a deck or patio. Mainline Materials has a Micro Channel system configurator that produces an instant parts list once you enter your linear footage, colour, and outlet type.

Where the Micro Channel is used

The Micro Channel suits pool and spa decks, concrete and paver patios, and walkways with light flows where the most discreet possible drain is wanted. Its ultra-low profile also works well against tile and pavers, and around entryways and garden paths. In each case the job is the same: collect nuisance water and route it to drain pipe before it makes a surface slippery or stains it.

For slightly higher flows or wider coverage, the Slim and Mini Channel lines are the next steps up — the Slim Channel is 2-1/4 inches wide, against the Micro's 1-1/4 inches.

The Slim Channel at 2-1/4 inches, the next size up from the Micro Channel.

Choosing the Micro Channel

Choose the Micro Channel for the lightest flows and the most discreet look in a pedestrian area. Move up a line if the run needs to carry more water, if you want a wider capture width, or if anything heavier than foot traffic will cross it. The Channel and Trench Drain Selector can confirm whether the Micro or a larger line fits your runoff and your traffic.

Installation: slope, base, and concrete surround

The Micro Channel installs with a concrete bed, a gentle slope to the outlet, and a concrete surround, with its integrated grate finishing flush with the surface. The NDS plastic channel lines generally follow the same core method: a levelled base, positive slope toward the outlet, and a concrete surround that locks the channel in place.

1. Excavate the trench. Dig along the drainage line wider and deeper than the channel itself, leaving room on the bottom and both sides for a concrete bed and surround. Follow the NDS installation detail drawings for your line and your project drawings for the dimensions.
2. Set a slope toward the outlet. Surface drainage needs fall to move water. A commonly used target is about 0.5 to 1 percent, which works out to roughly 1/16 to 1/8 inch of drop per foot of run, pitched toward the outlet end. On flat sites you create this by grading the trench bottom; check it with a level and string line before you commit.
3. Lay a concrete bed. Place a bed of concrete in the bottom of the trench and seat the channel into it at the right height and slope, so the top of the grate finishes flush with the surrounding hardscape.
4. Hold the channel in position. Use the anchor clips or installation stakes specified for the line to hold the channel at the correct height and alignment so it cannot float or shift when concrete is placed around it.
5. Pour the concrete surround. Place concrete up both sides of the channel to encase it. Keep a protective cover over the channel opening during the pour so concrete does not enter and set inside.
6. Finish flush. Bring the surrounding concrete or pavers level with the top of the grate so water sheets cleanly into the channel and the grate is not a trip hazard.

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 channel lines, grade the trench bottom to roughly 0.5 to 1 percent toward the outlet — about 1/16 to 1/8 inch of drop for every foot of run. The Dura Slope line removes this step by building slope into its stepped sections, so the trench does not need pitching. Either way, confirm positive drainage with a level before the concrete sets, because corrections are difficult afterwards.

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. Bedding and surround dimensions vary by line and by the traffic the finished surface will carry, so work from the NDS installation detail drawings and your project drawings rather than a general figure. For the Micro Channel specifically, remember the constraint above: it is a pedestrian-rated product, so if the surround needs to be built for vehicles, you need a different channel line rather than a heavier surround around this one.