Over the past couple years we have posted several articles discussing catch basins and catch basin installation. More specifically, we have found ourselves focusing on the broad selection of catch basin products for yard and downspout drainage manufactured by National Diversified Sales (NDS).

This article is devoted to one of my favorite NDS catch basin products called the Next Generation Basin, or 1200 NGB. The 1200 NGB is a unique 12” x 12” catch basin that allows you to adjust the invert elevations of the catch basin without changing elevation at grade (at the grating). No other residential grade catch basin has this feature!

next generation basin, nds, plastic drain

Take a look at the 1200 NGB catch basin kit (above), which contains two open adjustable wall panels. The round openings in the basin’s wall panels are specifically designed to accept one of NDS’s universal outlets.  So, not only are the inverts for the 1200 NGB adjustable, but it can fit a variety of piping options, too.  In the photo below, a 1243 pipe adapter is shown alongside a panel wall.

residential drainage systems, 1200 NGB, residential catch basins,

If only one outlet is needed for the catch basin, the 1266 plug adapter can be inserted to seal up the wall.  NDS also offers a solid wall panel (or plug side) can be inserted to close the open side (see photo below).  Still, the plug side does offer a knock-out for a pipe adapter if you later change your mind about having an outlet at that location.

plastic trench drain, catch basin system, residential trench drain

The 1200 NGB system was developed to make catch basin installation easier and more convenient. You can see in the photo below that it has three snap off side-outlet options, each changing the slope of drainage slightly. The lowest setting eliminates most sitting water from the basin, leaving less room for a sump to catch debris but draining the quickest. The center setting is the standard and connects with the middle of the catch basin. The highest setting gives the catch basin more elevation for drainage that needs to travel a longer distance. Depending on the situation, each of these outlets can be just what is needed to complete the job.

 plastic catch basin, plastic channel drain, plastic trench drain systems

The 1200 NGB basin also gives you options in bottom discharging. In the bottom of every basin is an adapter knock-out (similar to the plug side knock-out), which can attach to solid a PVC pipe that feeds off your drainage system.  By attaching the bottom outlet to a perforated pipe, you can create a leaching system uses storm water to recharge the ground water.   Small “weep hole” knock-outs are also located in the bottom corners of the catch basin for those who are just trying to rid the basin of standing water.

The fourth option offered by the Next Generation Catch Basin is a total bottom cut-out, which allows the maximum amount of storm water to be put back into the ground. As the ground becomes saturated, excess water reaches the pipe elevation and is taken away in the drainage system. Though this option maximizes the water that remains on site – a popular choice among those interested in water sustainability – it is not the best option next to home foundations.

One of the best things about the 1200 NGB system, though, is the amount of grating options available for it. Standard plastic grating comes in 4 colors: black, sand, green and gray. Also, there are bronze, brass, galvanized steel and cast iron options. Below are examples of the  standard slotted cast iron grating (left) and the black plastic grating (right).

cast iron grating, plastic grates, nds, iron grates

Other ornamental cast iron grating options are manufactured by Iron Age Designs are also available for this catch basin. Below are four gorgeous patterns that are popular in patio and downspout catch basins. Clockwise from the upper left, the pattern names are Interlaken, Locust, Sun and Oblio.

 decorative cast iron, cast iron grates, iron grates, Iron Age Designs

These grates fit perfectly with the 1200 NGB.  What makes the designs so fantastic is how each one incorporates a different image of nature into what would otherwise be a simple work of cast iron. The Interlaken Grate on the top left has a beautiful yet strict design; it must be a representation of the solid form of earth.  On the top right, the Locust Grate provides a breezier feel; the leaf patterns soften the harshness of the material until it seems to flow.  With the grate pictured on the bottom left, the Oblio Grate, you can get a sense of water in the concentric circles; the grate is reflecting the distorted surface of water during a rain.   At the bottom right, the Sun Grate exudes warmth and intensity; the sun seems to pop out of the plain background of circles.   Consider painting this grate in bright colors prior to installation.

Thanks for stopping by our blog to learn about the Next Generation Basin, the catch basin that does what no other residential basin can do!  All of the products mentioned in this article are available from Trench Drain Systems.  Call them toll-free at 877-570-2333 or email your inquiry to sales@trenchdrain.biz.



National Diversified Sales (NDS) is a plastic trench drain manufacturer based out of California.  They have a fantastic selection of plastic trench drain systems that are used in residential and commercial applications.  The 3 inch-wide Mini Channel is popular because its honeycomb design and inexpensive price appeals to contractors and homeowners.  However, a big part of the drainage system’s popularity comes from the number of complementary grating options offered. 

plastic grating, slotted grates, plastic trench drain system, trench drain grating

The standard grate offered with the Mini Channel is still a 3 foot long plastic grate, which is offered in six colors (gray, white, green, black, red, and sand).  Gray was the go-to color in the past, but customers are now branching out for colors that blend with the hardscaping; sand and white plastic grates, especially, are gaining popularity.

 national diversified systems, slotted plastic grates, brass grating, trench drain grates

For those with a more discriminating taste, NDS offers two slotted brass grating options.   The 1 foot long brass grates come in a satin or polished finish. Besides being simple, shiny, and elegant, they contain chamfered holes for optional screw placement, which helps keep the grates secured in the channel.

Another option available for Mini Channel customers is decorative cast iron grates.  These aren’t the ordinary slotted grates of yester-year; the cast iron grating product lines below illustrate the beautiful side of a functional product that was previously considered a necessary – and ugly – evil by many homeowners.  (Note:  these grates are shown with a baked-on oil finish unless otherwise specified but come standard in an unfinished cast iron.)

trench drain grating, iron grating, decorative grates, cast iron grates

Currently, four styles of cast iron grates work with NDS’ Mini Channel system: the Interlaken, Carbochon, Locust and the Minnione.  There are a few basic differences between these four Mini Channel grates.  The Interlaken is an intricate geometrical pattern while the Minnione has a flowing design.  The Locust pattern evokes the feel of leaves blowing in the wind.  Meanwhile, Carbochon’s open area is only accentuated by its bold pattern.

Style aside, the most noteworthy difference in the grates is length. The Interlaken (11″ long) is an inch shorter than the Minnione and Locust grates (12″ long).  The Carbochon (14” long) outdoes all three grates by inches.  I think the length of the grates is important because it determines what you can do with the design of the run.  Unfortunately, it is often overlooked during the planning stage and leads to extra work later on.

pool deck drains, channel drain, nds drains, plastic channel drain, decorative grates

Another difference in the grates is how they fit into the Mini Channel.   Take a look at the photo above. Minnione, the thinnest grate, does not rest in the channel with the same depth that Interlaken, Locust and Carbochon do.  While the other grates are cast with tongues that fit snugly into the Mini Channel’s patented “flying buttress” lip, one gets the feeling that the Minnione sits on top of the drain rather than resting inside it.

decorative grates, cast iron grates, trench drains, iron grating

The foundry uses cast iron as the standard material when making these decorative grates but also manufactures cast brass, bronze and aluminum grating for an additional cost. We should note that cast iron grates are uncoated (raw) and will form a rust coating over time.  The rusting process, when reproduced artificially to save time, is called a baked-on oil finish.  I find the resulting patina charming.

If your application doesn’t support this view, though, consider painting with an epoxy or powder coating. The powder coating process smoothes out the natural texture of the cast iron grates, giving them a softer, less metallic look.  You can really feel the difference between the painted and baked-on oil finishes; the process encased these grates in paint rather than changing their outer layers.

Let me just demonstrate the difference between the two available finishes in another way.  Look at the Interlaken grates shown below:  in terms of color, they are very similar.  But, if you look closer you can see the different shine, the thickly coated surface of the grate on the right.  It’s been powder coated.  The grate on the left, though, has a baked-on oil finish.   I’ll leave you to decide which one you like better.  For additional information on cast iron grating finishes, visit our “Cast Iron Finishing Options” blog.

foundry grating, cast iron grates, Mini Channel, pool drain system

Cost is all in a person’s perspective, especially when talking about trench drain products. A simple plastic grate that comes in six basic colors is available for a very low price per foot. NDS’ brass grate, a beautiful, no-hassle solution for those still worried about rust or decor, is the most expensive. The cast iron grates, which add style and variety, come for the more moderate price that falls somewhere in between and have beautiful finish options. They are the true extra mile, the art to efficiency, and are the balance if a cost-efficient and stylish grate is desired.

For cut sheets and literature on the products discussed here, download the available drawings embedded throughout the article.  If you’d like a quote on a Mini Channel drain system or decorative cast iron grating, contact Trench Drain Systems (TDS) at 866-570-2333 or visit them on the web at www.trenchdrain.biz.


Part 1.  Channel Body Comparison

There are many plastic trench drain manufacturers in the marketplace.  By far, the top two manufacturers are Zurn Industries and National Diversified Sales (NDS). Zurn is a world class plumbing supply manufacturer headquartered in Erie, PA.  One of the four business grouping Zurn has is Drainage Products.  The Perma-Trench products represent the plastic trench drain component of their drainage products offering.  NDS is a manufacturer of plastic components used in storm water management, irrigation, water flow control and landscape water and root management.  They are headquartered in Woodland Hills, CA.

These two very different companies find an overlapping marketplace with their pre-sloped, high density polyethylene product lines.  For NDS, their Dura Slope product line was an outgrowth of their landscape drainage product line development.  This product was meant to be a high performing drainage product used in larger landscape and residential projects.  The Zurn Perma-Trench products (all high density polyethylene) were developed as an economical alternative to polymer concrete trench drain for industrial drainage applications.  The work horse of the Zurn trench drain product line is their 4” wide channel call Z886.  Both, Dura Slope and Z886, have similarities in channel composition and drainage capabilities.  However, each has strengths which should be considered when choosing a product for a particular application.

Dimensional Comparison – Above is a photo comparing the Zurn Z886 and Dura Slope channel bodies as received from our supplier.   At first glance, the main difference you see when comparing two is the length.  The Zurn product is 2 meters (80”) in length while Dura Slope is 4 feet (48”).  Next, you will notice that the Dura Slope has a black plastic cover attached with locking devices.  The Zurn channel has 4 metal “spreading bars” which are used to keep the channel walls from flexing during installation.  Dura Slope’s black cover helps to prevent channel compression during concrete placement, but also works to keep channel free from debris during drain installation.   As a side benefit, the locking devices come free with the Dura Slope channel.

The channel width, slope and colour are relatively similar between these two products.  And likewise, both products can achieve continual slopes of 100 feet (96 in the case of Dura Slope) and have the deepest channel section being 12”.   Look at the close up photo comparing the two below.

Flow Data Comparison – The flow data reported on the Zurn product is 20-25% higher than that reported on similar invert depth Dura Slope channels.  This didn’t seem reasonable since both channels are so similar.  To investigate the disparity, I compared Z886 and Dura Slope channels of similar depth. (See Photo Above)  Flow rate is a function of the cross-sectional area of the channel, the channel slope and the channel material.  As the material in each is HDPE, we can ignore this as a factor of the flow difference seen.  The cross sectional area of each channel seemed to be similar.  Z886 is a full 4” wide with a rounded section at the bottom.  Dura Slope has a top width of 4.5”, but, then goes into a taper to the rounded bottom which has a 4” diameter.  Maybe, Zurn has slightly more area…maybe.  Could the extra 0.05% slope of the Z886 explain the 20% greater flow data?  I don’t think so.

Upon closer analysis, I learned that Zurn’s technical data defines the invert depth of a channel to be the distance between the top of the grate and the lowest point in the channel.  Dura Slope, on the other hand, measures the invert depth as the distance from the bottom of the grate to the lowest channel point.  The resulting 0.75” difference has an effect on the overall cross-sectional area calculation, and in turn, affects the flow calculation.  In essence, Zurn measures flow of the channel without a grate while Dura Slope recognizes that you will have a grate in the trench while it is in full flow.  When each company’s data is compared after adjusting for this depth difference, Zurn shows only an 8% higher flow rate than Dura Slope.

Channel Feature Comparisons – Other channel features worth noting include built in rebar clips and anchors, built-in bottom outlets, channel connections and end outlets.  Both Zurn and Dura Slope products have rebar clips built into the channel body.  (See above.)  Rebar clips are used to help suspend the channel within an excavated trench during installation.  Rebar sections are generally hammered into the ground.  The purpose of the rebar clip is to attach the channel to the embedded rebar.  The rebar clip designs for the Z886 and Dura Slope channels are different but equally functional.   Z886 has a side clipping design while Dura Slope has a clip opening that is perpendicular to the channel.  Both clips have tie wire holes.  The Z886 wire tie hole is in the outer most side of the clip.

Rebar clips are additionally helpful to stabilize and secure the channel after it has been set in concrete.  One complaint I’ve heard about plastic trench drain channels (as opposed to polymer concrete) is that,  over time, there is a tendency for the channels to separate from the hardened concrete, leaving a gap that can fill with debris and pinching the channel opening. In comparison to polymer concrete channels, this is probably a true statement, though maybe a little misleading.  To help secure the channel firmly into the concrete and minimize this separation, Zurn has designed additional anchor posts at each rib point of the channel.  Dura Slope doesn’t have additional anchors at their rib points.  However, the HDPE used to make the Dura Slope product seems to be more rigid, maybe because of added fillers used in the plastic.

A feature of every Dura Slope channel is a built-in bottom outlet. This gives the contractor flexibility in deciding the drainage points of a long run or the convenience of not having to order a separate adapter if a bottom outlet is required.  To use the bottom outlet, a 4” diameter hole bit is used to drill out an opening in the channel within the bottom outlet.  Thereafter, a 4” schedule 40 pipe hub or Sch. 40 hub insert (DS-126) can be attached.

plastic bottom outlet drainage

Zurn’s Z886 bottom outlet design also gives you a degree of flexibility.  The Z886 doesn’t have a built-in bottom outlet with each channel.  However, separate bottom outlets are available in 2”, 3”, 4” and 6” diameters.  These can be installed anywhere along the channel bottom which allow for more complex drainage configurations.


channel drain connection

Both Z886 and Dura Slope have tongue and groove joint connections.  They allow for quick and easy installation.  Dura Slope has a trademarked DuraLoc TM design which snaps to lock the channels together once the tongue has been properly inserted into the groove.  I am impressed to see how quickly these go together and how straight the channels remain after connection.

The Zurn tongue and groove joint connection slides together easy enough.  But, it just isn’t as user-friendly as the Dura Slope product.  To secure the joints into place, you are required to place a screw at each side of the joint so you can mechanically connect the channels.

One of the selling points for the Z886 channel in Zurn literature is the fast installation times due to the tongue and groove connection and the 80” channel lengths.  The longer channel lengths are thought to reduce the hassle of connecting channel (which is what takes time in setting drain).  When compared to traditional polymer concrete systems, this may be true.  However, you cannot make the same inference when comparing Dura Slope and Z886.  I feel the quick locking channel design feature of Dura Slope overshadows any installation advantage that the Z886 product may have despite the longer channel size.  Dura Slope is just easier and quicker to assemble.

While I’m on the soap box commenting about channel length, I want to point out that long channel lengths are best when you have larger, longer channel runs.  For smaller projects, you may not have need for a full 80” section.  For common trench drain applications, such as a 12 ft or 16 ft wide driveway drain, a channel with a 4 foot length would be optimal.  If an 80” channel was to be used on this project, a portion of the channel would have to be cut and discarded.  As the project becomes larger in scope, a certain amount of flexibility is inherited.  Lengths can be changed easier in the field to accommodate the channel increment.  And with larger projects, if a channel is to be cut and discarded, it is a much smaller percent of the project cost than it would be in a small residential project.  This is not to infer that smaller length channels shouldn’t be used in larger drainage projects.  Smaller channels can be quicker to install, and they are easier to store.

One feature that aids Z886 in large drainage projects is its extender panels.  These are wall panels that can be added to a channel to allow the drain to be installed at greater depths or with longer continual sloping runs.  Dura Slope doesn’t offer this feature.

A final feature to compare between these two systems are end caps or end outlets.  Both products have caps and outlets made from HDPE, which makes it easy to trim and drill out in the field using standard power tools.  Both have a design that allows the outlet to attach by inserting into a channel groove and the end cap (shallow end) to be attached with screws.   Zurn’s outlets are supplied with screws, while Dura Slope requires you to purchase these separately.  There will be an excess portion of the cap which needs to be removed, with both systems, to make the cap level with grade.  Dura Slope end cap design shows a depth scale that corresponds with the channel you are using as the last channel to make trimming easier.  Zurn’s end cap design has a saddle that rests within the channel to make screw mounting easier during installation.

To recap, below is a quick comparison of the Z886 and Dura Slope with respect to channel features and geometry.

Parting Comments – If we are to look solely at the merits of each channel, I would say that Dura Slope has more to offer both home owners and contractors.  The Dura Slope was designed to be easy to handle, quicker to install, with minimal assembly required.  I personally like the shorter channel lengths because they fit on my shelves and are much easier to ship to my customers.   I feel the plastic used to make the Dura Slope is stiffer than that used in Z886, which leads to straighter channel installations and less channel-concrete separation.

Having said that, I acknowledge that the Z886 channel has advantages over Dura Slope in applications where long, continuous slopes are required.  By using extender panels, runs as long as 300 feet of continual sloping drain are achievable.  In addition, Z886 has a wider variety of outlet diameter options which can help in more complex drainage projects.  This is one of the reasons why you will see Zurn Z886 specified on big jobs more often than you will see Dura Slope.

The channel component of any trench drain is important when considering the engineering properties and installation.  But this is just half of trench drain.  The portion of the drain that people see after installation is the grate.  Increasingly, the channel grating is becoming the focal point of the trench drain selection process.  Aesthetics, ADA compliance, load capability and corrosion resistance are all properties to consider when selecting a trench drain grate.  Part 2 of this report will continue the discussion on Zurn’s Z886 and NDS Dura Slope by focusing on trench drain grate options available from each.

Trench Drain Systems is a company which specializes in providing quick solutions to drainage problems.  For more information about the trench drain products discussed in this article, visit www.trenchdrain.biz or call 866-570-2333 for immediate assistance.