Every so often an ADP (American Drainage Products) plastic grate is mistaken for NDS Spee-D Channel. There is a good reason for that. ADP was a company based out of Columbus, Ohio who carried a product line that overlapped with those offered by NDS (National Diversified Sales). In 1997, NDS purchased ADP and incorporated its product line into the NDS offering. The redundant products have been supported by NDS over the years but are being phased out. That is the case for the ADP 2” and 4” channel drains. Replacement components, such as plastic grates, and some channels are still sold by NDS, though they are difficult to locate.
ADP 2” Channel Grate – As first glance, the 2” ADP grate can be mistaken for an NDS channel grate because it is made in the same style as the NDS Mini Channel. The thin, slotted plastic grates come in an assortment of colors (shown below). The slots have a center rib running down the length of the grate, which makes it more structurally sound and gives it the “double slotted” look.
Distinguishing features between the two grates can be seen in the photos shown below. While the Mini Channel grate (left) is 2.75” wide and 36” long, the ADP Channel grate (right) is 2” wide and only 24” in length. Another subtle difference between the two can be seen in the screw hole locations. The longer Mini channel grate only has four locations screw holes used to attach the grate to the channel while the 2” ADP grate has six screw holes.
Grates are not the only replacement component available for the 2” channel system. End caps, channel couplers, and channel supports can also be purchased for this system. Channels are available in 4-foot lengths but are not being advertised because NDS is trying to phase out this product line. If you like this product, you’d better hurry before it is gone forever.
ADP 4” Channel Grate – For the longest time, I incorrectly thought that the ADP 4” channel was a Spee-D Channel system. The two products are so similar, it can fool you. I was first introduced to the ADP 4” channel when I was replacing a trench drain in a customer’s driveway. The 4” channel drain had been installed in the drive without the proper support by the previous contractor and failed underuse. When I removed the channel, I recall thinking that this must have been an older version of the Spee-D channel because it had a few style differences yet still looked identical to the Spee-D Channel.
Many similarities exist between the Spee-D and ADP 4” systems. Channels are extruded gray PVC plastic and supplied in 10-foot lengths. The 4” wide grates are 24” long and are slotted with similar slot design. But upon closer evaluation, the Spee-D grate (left) is about 1/8” narrower than the ADP 4” grate. In addition, the ADP grate (right) has slots with squared corners and screw holes that are directly opposite of each other.
Many more differences are apparent when you compare the bottom side of these grates. The Spee-D grate has a thicker, shorter rib section which defines the slot. The ADP 4” grate has thin, deeply protruding rib sections. These thin ribs, while making the grate more rigid, may also make the grate more brittle and easier to crack during aging. Another difference between these two grates can be seen in the lips that fit into the channel: the Spee-D grate has an elongated edging while the ADP product has a V-notch.
There are other grating options for the ADP 4” wide grate. One really interesting option is the flanged grating (shown on the top in the photo above). The purpose of the flange was to cover up or mask the plastic channel edging so there would not be a color mismatch in the trench drain after installation. I suspect, however, that the edging tended to fatigue and break underuse. Maybe this is why NDS hasn’t used this idea in its existing product lines.
The ADP 4” grates of both styles are available in four colors: black, sand, green and gray. The flanged 4” wide grate is also available in the color “brick”. End caps, outlets, couplers and channel supports are also available for this system. While NDS no longer advertises these channels, they are available (for now).