It had been 10 years since I had been to a professional baseball game and even longer since I had been to a game in my hometown of Kansas City, Missouri.  Back in the mid-1970′s, I worked as an usher at Royal Stadium – as it was called then –  with a bunch of my high school friends.  Those were the days of George Brett, John Mayberry, Freddie Patek, Willie Wilson and Amos Otis, to name a few.  It was a great place to spend the warm summer evenings and make a little extra money.  I thought it was the best job in the world.  Go figure, they actually paid me to go to baseball games and work on the club level.  Now back after 30 years, I can see how the place had changed.  The stadium, now called Kauffman Stadium, had recently undergone a well deserved facelift.  A new museum, new seating, new scoreboard and new restaurants are all part of the new landscape.  I was impressed.

I was in Kansas City on business, but it would have to wait.  The Oakland A’s, an old rival of the Kansas City Royals, were in town for a match-up.  I remember seeing the Kansas City A’s play in Municipal stadium back in the 1960′s when owner, Charlie Finley, was in his glory.  The A’s – Kansas City rivalry was initiated the moment Charlie “O” sent the A’s packing for their new home in California.   Of course, this was pre “Moneyball” days for the A’s, but still very much a circus with Finley as the ringleader.  I was looking forward to seeing these two teams slug it out and hoped to walk away with a small portion of revenge.

The warm day was perfect for baseball.  The sun was shining and people were smiling.  We went with some family members and sat a few rows behind the home team dugout.  It just happened to be “Cap Day,” so we were all rewarded with a baseball cap upon entering the stadium.   The Royals Franchise had recently acquired Jeff Francouer and brought in a rookie outfielder, Eric Hosmer.  Both Francouer and Hosmer had hits in the game.  For Hosmer, it was his first major league hit.  The game was exciting.  The score was 3 to 3 in the eighth inning.  The Royals loaded the bases in the ninth inning and won on a sacrifice fly.

Then the game was over.  We hadn’t noticed that it was evening already.  People lingered in the stadium, chatting in a friendly, mid-western kind of way. We watched the light dance in the scoreboard fountains, a delightful end to a wonderful day.  And, though I was unfamiliar with the current team players, it didn’t matter.  This was baseball as it is meant to be.

All of this does lead up to the topic of trench drain.  The only thing that could make this evening more complete, more perfect, was to find a couple of interesting trench drain examples to explore.  The first example was seen near the general admission section of the park, near the Hall of Fame Building.  This particular area is not protected from rain by any sort of roof or canopy, so it gets a fair bit of direct rain water.  There I found a heel-proof cast iron grate that had been arranged to form part of a radius drain.  (See below)  The grate was 8 inches wide and 24 inches long. It was in a painted steel frame (now rusting) and showed no visible locking devices.  It did not display a manufacturer’s marking and, to make things more interesting, was galvanized.   I stood looking at the grate for a while trying to determine the source.  My conclusion…..it had to be a custom product from a local foundry.

Heel-proof cast iron grates are becoming more popular in applications with a high concentration of “professional” pedestrian traffic and light vehicle traffic.  In the trench drain world, “professional pedestrian traffic” refers to situations where women wearing high heeled shoes with small diameters may be walking.  Usually, professional office workers, (lawyers, product managers, engineers, physicians) fit this description.  This type of grate became vogue in an effort to minimize lawsuits associated with tripping hazards.  (Side note:  I’m not suggesting that there isn’t a large amount of professional women strolling the general admission section of a Royals game on a Saturday night.)

The fact that the grate was used in a radius trench drain is not surprising.  The “illusion” can be used on large sweeping radiuses while using a standard grate.  You only need to be able to bend the angle iron railing to the curvature required and install the straight grates.  If your desired radius is 75 feet or greater, you should have no problem making this work since the spacing between the grates will mask the lack of radii.  On radiuses of 60 feet or less, I generally recommend using a grate that has been manufactured to display the proper curvature and non-parallel ends.  From my experience, few radius grates exist that aren’t decorative and are designed for a specific radius.  For more information on this topic visit www.ironagegrate.com.

I learned a little bit more about these grates a month after I visited the stadium.  There was a situation in the stadium next door, Arrowhead Stadium, home of the Kansas City Chiefs football team, where they wanted to replace some grating that was breaking.  An engineer from a local construction company called me to discuss a situation in which the fork trucks delivering supplies to stadium concession stands where driving over 8 inch wide galvanized cast iron grates,  causing them to pop up from the trench frame and eventually break.  The company was hoping to replace all the grates with a custom reinforced stone grating manufactured by Jonite.  In our discussions, it was mentioned that the problem grates were 1 inch thick, were made specifically without a manufacturer’s identification and were later galvanized. The grate was purchased by the plumbing contractor on the job, and I assume it was from a mid-west foundry.  My guess:  we are talking about the same grate.

The second example of trench drain was found in the street that ran in front of the two stadiums. This drain, shown in the photo to the right, actually appears to be a slot drain.  A slot drain can be thought of as an underground drainage pipe that has a slot shaped extension rising from the pipe to be flush with the ground surface above.  The slot forming material can be made from a number of materials and the slot can be a multitude of widths.  The overriding characteristic in all slot drains is the narrow geometry of the slot width in comparison to the underlying conduit. Now I’m not 100 % sure of my guess on this identification. If anyone reading this article can help identify this product, I’d be grateful.

No matter.  I’m familiar with a couple of slot drain products.  The first that comes to mind is the Zurn Z888 family of products.  They have slot drains ranging from 4″ diameter pipe with a 3/4″ slot extension to 36″ diameter conduits with 3″ wide slot extensions.  These products are made of HDPE and come in standard 4 foot lengths.  The slot riser in each Z888 product is formed into the conduit body.  Material options for the riser neck are available in the event you need a ductile iron or stainless steel slot in the finished floor.

A number of the polymer concrete trench drain manufacturers make 3/4″ galvanized steel slot extensions that can be placed on their trench drain channels to simulate the slot drain opening.  These products have the added advantage of being part of a pre-sloped drainage system.  A slot drain, on the other hand, is a non-sloped product by its very nature.  However, if the drainage surface has a natural grade, the underlying pipe will also be sloped.

A number of slot drain making components that allow you to convert standard drainage pipe to a slot drain are on the market.  I’ve seen a polymer concrete “slot riser” made by ABT that is inserted into a longitudinal cut along the length of a 6″ diameter schedule 40 pipe.  Another manufacturer uses the same “slot riser” technique with larger diameter pipe.  If I recall correctly, this product is made from galvanized steel, as well.

Regarding the slot drain shown here, I felt the use of expanded metal mesh for the grating was significant.  This irremovable mesh was part of the neck.  A trench drain would need a removable grate for occasional cleaning.  An immovable grate suggests that there is a large conduit below that would not require constant maintenance.  The 2 inch wide slot also leads me to believe that a large pipe lies underneath the 6 inch long neck.  And, if you saw the streets at this stadium, it is apparent that this is the sole method of storm drainage in this location.  There has to be a BIG pipe connected to this slot.  I just wish I knew for sure.

Writing this article, as was previous blogs, was thought provoking and educational.  It required that I put my thoughts about these topics in order, that I gathered meaningful and factual information to share, and that I communicated in a way that is easy for all to understand.  In the process, I realized that I was silly in high school for thinking the best job in the world was working for the Royals.  As it turns out, NOW I have the best job in the world.  Where else would I be able to travel the world, meet interesting people, see interesting cultures, study drainage systems and products, and then write about a topic I like?  If you have a topic you want me to discuss in a future blog article, send me your request at michael@trenchdrain.biz.  If you have specific questions regarding trench drain products, installation, or recommendations, don’t hesitate to contact us at by email at sales@trenchdrain.biz or by phone at 610-638-1221.  Thanks for visiting this site!

How do French Drains and Trench Drains Differ?

Many people – including contractors! – aren’t aware of the difference between trench and French drain.  There is a significant difference between the two, and we’ll explore it with some general information below about the types of drains.  But first, and generally speaking, French drains are used to remove ground water while trench drains are used to quickly remove surface water.

The History of French Drain

For starters, there’s nothing Françoise about French drains.  They originated in Massachusetts (USA) during the 1800s by way of farmer Henry French, who later wrote a lengthy book on farm drainage. (French, Henry F. (1859). Farm drainage: the principles, processes, and effects of draining land with stones, wood, plows, and open ditches, and especially with tiles. New York: Orange Judd & Company.)

Originally, the drains were hand-dug trenches which were re-filled with a thick layer of gravel in the base and standard soil extending to the surface.   The gravel base offered a sturdy, yet porous, conduit for water to be collected and drained from the surrounding water-drenched subsoil.  Henry French later began lying stacked, though slightly spaced, roof tiles at the center of the gravel conduit to help facilitate water transportation (an early form of clay piping).  These tiles, after a time, became perforated before evolving to clay pipe.  As perforated piping became more widely used, the size of the gravel used to fill the drain had to be “engineered”.   Coarse gravel was used surrounding the perforated clay tile which gave a high permeability to the drain.  Finer sized gravel was used as a protective layer between the coarse gravel and the soil which helped filter fine dirt particulate from entering and eventually clogging the drainage system.

Modern French drains have evolved from their 19^th century counterparts.  While still hand dug in residential applications, they are more often excavated with machinery.  Though some drains are still strictly gravel-filled trenches, the majority of French drains now use perforated (smooth walled or corrugated) pipe at the core of the gravel bed.  The basic premise is still the same; provide a highly permeable, rugged structure to evacuate water from saturated subsoil.

Making a Conventional French Drain

A French drain is easy to make but a bit time consuming. First you’ll need to dig your trench (for a 3”- 4” diameter drainage pipe, a 9” wide trench works best).  You will need to grade the trench during the dig; the best way to ensure a continuous slope is to measure as you go.  Optimally, the gradient should be 1’ drop per 100 ft – or, a 1% slope.

After the trench is dug, line it with a filter cloth and pour in a layer of coarse gravel before setting the pipe.  Half – to – 1” diameter rocks are typical, but it is best for them to be over 1”.  They should have minimal particulates that would clog the piping.  Some people put a special pipe sock (made from filtering material) over the pipe to keep out the finest of particulates.

To finish the French drain, cover the pipe with gravel, then fold and seal the filter cloth securely and backfill the trench with soil.  Use coarse, sandy soil for better drainage.

New French Drain Products

The market has developed several innovative round French drain products that take away much of the work involved in installation.  The structure of these products include universal components:  a corrugated polyethylene pipe with perforations surrounded by polystyrene aggregate, all contained in fine mesh netting.  The result is simple, a pre-packaged French drain that is much less time consuming than a conventional trench and can be cut off at any length.

NDS offers residential (EZ-Drain) and non-residential (EZflow) French drain systems.  While the design of both products is inherently the same, the EZflow is offered with 3”, 4” and 6” corrugated piping to accommodate varying groundwater saturation levels while the EZ-Drain only offers 4” piping for smaller, residential projects.

The deepest you can bury this type of French drain system is 10 feet, which poses nothing to worry about in most applications as it is more than enough for the system to sustain traffic.  Actually, at 12 in. deep a system will withstand 16 thousand pound loads and single pass construction.  Anything less risks damaging the product if vehicles drive over it, though the minimum depth to install a French drain system is 6 inches.

Another French drain system is Multi-Flow by Varicore.  Though Multi-Flow tries to separate itself from its humble roots, it is undeniably derived from French drain.  It is a subsurface drainage product composed of corrugated piping wrapped in geotextile fabric (reportedly, it will not clog over time like French drains do).  The product does have a few substantial differences, however, that at least make it superior to conventional French drains.

Multi-Flow touts itself as a vertical system, and it is.  The system is only 1.25” wide but can come in 6” (seen below), 12” and 18” tall panels.  The structure is a series of thin corrugated pipes stacked atop one another, creating more surface area than other products and therefore draining water more efficiently.

Multi-Flow can be installed in a 4” wide trench, which requires less excavation and backfill.  The system recommends the use of coarse sand as backfill rather than native soil because the silt and clay particles would eventually clog the geotextile filter.  During installation, fill the trench with clean, coarse sand.

Multi-Flow offers more flexibility than other systems, including couplers, tee connectors that join three or more segments of drain, end caps and side outlets.  The product can bend in a 6” radius (enough for a 90 degree turn) but offers an optional 90 degree corner pipe, too.

Something to keep in mind is that, while Multi-Flow offers many basic PVC connections as part of its system, many of the connections will also be available at the local hardware store and can also be used on NDS’s EZ products.

What About Trench Drains?

The history of trench drains isn’t so clear cut.  We’ve talked about this subject in one of our first blogs, “Consider History.”  There, we made parallels between modern trench drain and such drainage systems as the aqueducts of Rome before its fall and the open sewers of Paris during the Middle Ages.

Over the course of the Roman Empire, there were 11 aqueducts that supplied various cities with drinking water.  Over 200 miles of waterway used gravity to guide water into cisterns for distribution in cities like Rome.  The system bored through mountains and was at times elevated on arched bridges so the aqueducts could follow gravity directly to the city.  The above-ground troughs, which ran for only about 30 miles of the total system, are the most renowned pieces to the aqueducts and a model for modern trench drain.

Early in Paris’ history, drinking water was taken from the river Seine, and the waste water was thrown into the streets.  Because the streets were unpaved, the city transformed into a swamp of foul-smelling mud.  In the 1200s, the streets were cobbled and designed to have an open trench running down the center which would guide sewage back to the river Seine.

Disregarding the fact that the system drained sewage right back into the water supply, the open sewers helped spread the Black Death, which devastated the city.  Thankfully, they were replaced by the famed vaulted sewers in Napoleon’s era, and shortly thereafter, by the sewer system in use today.

Today’s trench drains come in widths up to 2 ft.  and depths up to 4 ft.  They take after their predecessors but are built for construction purposes – not for sewers and drinking water.  Typically, these drains consist of a preformed channel body and grating, which are installed in an excavated trench and then set in concrete.

Today’s trench drains can be cast from concrete, plastic, fiberglass, stainless steel and cast iron (though the last two are not as common).  They use grates both to keep debris out and as a safety precaution, and many systems offer catch basins to collect sediment and small particles so that the drain never clogs.

The Difference

The functional difference between the two is that French drains capture and evacuate ground water while trench drains are specifically designed to collect surface water before it can saturate the ground table.  I suggest that you evaluate your situation, and if you want to catch the water before it can sog up your yard – or if your ground has high amounts of clay, which isn’t that permeable and can contaminate looser soils – you might just want to go with a trench drain.

Visit www.TrenchDrain.biz for more trench drain information.

Goodness Gracious! I just returned from a pleasure/business trip to Brazil.  Though the weather was good at times, the majority of my stay was overcast and rainy. I have no complaints on the +80 degree weather in January, however. I was given time to see some torrential rainfalls and a steady use of drainage systems in two distinctly different locations.

The first part of my trip was to a city called Belo Horizonte. This is a city of over 3.5 million people and with a population in the metropolitan area of well over 5 million. It is located just 5 hours north of Rio de Janerio. Belo is in the heart of the state of Minas Gerias, which is known for mining, iron production, cheese and a rum-like drink called Cachaca. The terrain is hilly. The infrastructure is old. Housing is made from concrete and ceramic tile. The streets are a mixture of stone and asphalt patchwork. When it rains here, you see lots of fast moving water on the streets.

The second part of my trip was to Rio de Janerio. While there, I stayed in the upscale area called Barra (pronounced ba ha).  In contrast to Belo, the Barra has newer housing, a lot of construction, a lot of commercial property, concrete and asphalt streets and flat terrain. It is know for the beaches, night life and carnivaal. When it rains in Rio, the water doesn’t flow as quickly as in Belo. Still, trench drain abounds here, as in Belo.

Trench Drain In Belo Horizonte – The trench drain I saw in Belo was all cast-in-place. That is to say, that the channels were formed of concrete, generally with a iron shoulder to support a grate of some sort. Four types of trench grate were identified; none of which were heavy duty. These are:

1) No Grate — I was surprised how often grate-less trenches were used in sidewalks, streets, gas stations and parking lots to channel run-off water. If the channel is narrow or shallow, apparently it isn’t considered a pedestrian hazard.

 

2) Simple iron fabrication — Most grating I saw was formed from welded reinforcing bar or flat stock. The styles were rarely similar, indicating that they were fabricated with each construction effort. These were the most fun drains to find and were often on the hilliest slopes.

3) Cast Iron — In some of the more commercial residential areas, I found cast iron grating. The sections were generally a meter in length and seemed to be able to handle the small automobile traffic common to Brazil (Class C at best). I found some of this grating at a local hardware store. No brand names are available. And apparently, there is no attention given to market standardization.

 

4) Concrete — I did locate concrete grating in a couple larger residential applications. I saw concrete used more in municipal drains systems. I was told that in larger cities, people steal cast iron grates to sell for scrap. In these areas, concrete trench grates are becoming more common.

 

Trench Drain In Rio De Janerio — In contrast to Belo, the majority of the trench drain I saw in Rio was associated with commercial property. But, as in Belo, I saw only cast-in-place systems. This time, however, the grates were wide and manufactured (rather than custom). I want to identify four types of grating that I saw:  

1) Bar grating (steel) — This seemed to be almost an H-20 loading grate. What I saw was manufactured from welded bar stock . One particular parking lot had over 100 LF of 2 foot wide trench using this grating.

 

2) Bar Grating (polymer composite) — I’m still scratching my head on this one. I could swear I found grating made from polymer concrete. I would think that this grating would have to be wire or mesh reinforced. However, what I saw was cast and mineral based, and it seems to have a well thought out hold-down mechanism employed.

 

3) Cast Iron — Simple cast iron grating was found in some of the ramps I saw in parking garages. Unlike those in Belo, these seemed to be a more durable design capable of class D loads. Again, all grating was in one meter section, no mater of the width. I saw no locking devices.

4) Frame and Grate — I want to single out on type of cast iron grate which I feel is significant. At a grocery store parking lot, I found the use of a ½ meter square manhole frame and grates aligned in a series to make a trench drain. Though only 40 to 50 feet were found, it shows that excess money was spent to solve a drainage problem.

My observations of trench drain in the Brazilian cities of Belo and Rio are not exhaustive by any means. However, they are snapshots of what is being used in this country and have some value. Brazil currently has relatively cheap labor and “forgiving” building codes. The economy may not be ready for widespread use of the standardized trench drain materials currently used in Europe or North America. However, the infrastructure is ready. Architects and engineers need to start incorporating standardized drainage systems into the designs of new construction projects. Simple former systems (Econodrain www.econodrain.com) would be a logical place for this country to begin. And, as Brazil is a county rich with iron casting production, it seems that this trench drain system is a natural fit. View more photos that I took on this trip of trench drains in brazil.