Earlier in the year, I witnessed the installation of 40 LF of Polycast 600. Polycast 600 is a pre-sloped polymer concrete product manufactured by Hubbell. It is similar to many commercial grade products already out on the market. This particular product was sold with galvanized steel slotted grates and a steel channel protector. The channel protector (Polyguard) is a strip of galvanized steel that helps prevent premature edge deterioration of the polymer channel. The job

was located in the Pocono Mountains of Pennsylvania, earshot from the Pocono Raceway. The trench drain was to be installed in a new equipment storage facility. The floor of the facility was being pour at the same time as the drain in order to pitch the floor toward the drain.

Initially, the excavator roughed out a trench in which to install the drain. The site was already installed with gravel, but was not compacted.

(This will probably cause a problem in the future. The gravel base for trench drain and all concrete floor projects need to be compacted. This floor has an excellent chance of developing voids underneath the concrete in the future.)

The position of the drain was determined and a level line was set. Then, the trench was cleaned of debris to assure that the channels could be set without obstructions.

Next, the channels were set along side the trench in order that they would be installed. The highest number channel (deepest) was set at the discharge invert. The smallest channel number was set at the beginning of the drain flow path. For this particular installation, the channel protector and grates were both left in place. The grates were later protected with plastic sheeting prior to pouring concrete.

The discharge water was designed to exit the end of the drain through 4” PVC pipe. A hole was drilled through the foundation of the building for this pipe to exit. It was later tied into a drain pipe that took the water to a sewer.

Installation started with the deepest channel first, then proceeding upstream. The channels were connected to each other with an installation bracket and connected to ½” rebar (#4). This particular installation bracket is patented and used exclusively with the Polycast system. It makes installation easy. However, in this case, the installation would have been easier if the excavator hadn’t used so many large stones in the base. At times, large boulders have to be removed in order to hammer the rebar in the ground. No matter, the bracket was adjustable enough to line the channel up perfectly, even if the rebar stakes didn’t install perfectly.

From the photo to your left, you can get a better idea on how the Polycast installation chair works. Bolts from the installation chair fit into the “dimples” of adjoining channels to hold the channel tight. The bolts can adjust in our out to help align the channels left or right. The chair can also be adjusted up or down on the rebar to keep the top of the drain (grate) on level.

Once the first few channels were put into place, the remainder of the installation went smoothly. The channels seemed to fall into the proper place when the installation chair was properly used. In the end, we had a 40 foot length of polymer concrete trench drain, suspended in air, and ready to be set in concrete.

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 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. To see more photos I took on this trip, visit www.trenchdrain.biz/brasil2006

My daughter, Ligia, was in from Brazil to visit in March.  We took one weekend and went to Washinton DC to see some sights.  The weather was sunny, but cool.  (I think I got sun burn and wind burn at the same time.)

 While checking out the monuments (and getting a little sentimental), I was able to look at some trench drain.  Let me show you two that were interesting to me.

Trench Drain at the Lincoln Memorial Steps - These drains must have looked beautiful when they were originally installed at the base of the granite steps leading up to the Lincoln Memorial.  Now they sport a handsome green oxidation coat- the original finish must have been a brilliant bronze or brass.   These 4″ wide drains are filled with dirt and sediment, an indication that they probably are not pre-sloped.  (Maybe, also, an indication of the maintenance budget.)  I’m not certain they are really needed here, any way. 

No matter, the monument would look nicer if these drains were again put in service.  Any volunteers to help clean these out?

Trench Drain at the Native American Museum - If you like Native American Culture and artifacts, this museum has something for you.  I was impressed with a number of aspects of the buildings architecture.  The granite trench drain grates running through the courtyard and water sculpture areas caught my eye.

These grates are probably the most expensive pedestrian grates I’ve ever seen.  Let’s not even talk about the percent open space for efficient water drainage……  You can see they are ADA approved, but I’m not certain if they are heel proof.  Are those holes 3/8″ diameter or smaller ???

No matter, the weekend was beautiful and educational.  Maybe you have a unusual trench drain system or grate you want to share.  Let me know.  Thanks……………….Michael