In recent years, I have been traveling to Brazil with my wife over the Thanksgiving holidays to visit family and friends. It is a good time to visit Brazil since it is prior to the busy Christmas season and just the beginning of their summer season. School is still in session, so you basically have the beaches to yourself if you can find a day that the sun is out.

Lately we have been traveling to the Brazilian state of Espirito Santo where we have access to an uncle’s beach house. The drive is eight hours of mountainous terrain that takes you through the heart of their coffee growing region. Along the way, we occasionally stop at roadside luncheonettes for coffee and a piece of cheese bread. In 2008, we made a stop at one such location that just happened to be installing a trench drain. This drain ran along their sidewalk and out into the parking lot where it met with the gasoline pumps. At this time, I took photographs of the construction and filed them away, not really thinking I would be seeing them again.

Almost exactly one year later, I found myself at the same luncheonette to refuel our vehicle and have coffee. I realized when my wife and I arrived that we had been to this location before. This time, the trench construction was completed. I took more photographs to give my readers a before and after view of a trench drain installation that is very different than our approach in the United States.

In Brazil, they have a very different set of circumstances governing their construction industry. First of all, their high unemployment gives rise to low labor costs. Because of low labor costs, there is a tendency to use “man power” rather than “machine power”. For instance, in projects where I would use a backhoe to excavate a small section of ground, they would have a tendency to dig with hand tools. Also, as labor is cheap, there is less of a reliance of pre-manufactured or pre-formed construction materials. Sidewalks and parking lots are often made with tile or paving stone rather than concrete. If concrete is used in small quantities, the cement, sand and gravel is brought to the site and the concrete is batched and mixed by hand. Only on large construction projects is a ready-mixed concrete product brought to the site. 

In the case of a trench drain installation, this has big implications. There is no pre-cast concrete trench drain that is made off-site and dropped into place. There is no polymer concrete pre-sloped channel with locking cast iron grates to set in place with concrete. These products don’t even exist. Ready-mix concrete is cost prohibitive or difficult to justify on these projects. And, trench drain bar grating is often made by a metal fabrication company or made on site by a craftsman using local materials, such as rebar. However, cast iron and aluminum castings are available in specialty stores.

In this particular installation, the trench was to be used for drainage and for running a utility line. Paving stones were removed from the sidewalk and areas in the parking lot. The ground was hand dug to a 2 foot depth. Luckily in this part of Brazil the weathering of the soil is deep; the earth is predominantly sandy clay which can be hand dug easily when dry.

Three courses of 100mm wide x 200mm tall concrete block were laid for the walls of the trench. A frame for the grate was mortared to the top of the block. Portions of the block wall were cut away to accommodate placement of the frame anchors. The anchors were then mortared into place. To ensure a proper spacing between the two frame sections, a template was built which emulated the grate. This template was placed between the frames while it was being installed on top of the block wall. To make certain that the grate wasn’t going to fit too tightly, a metal spacer bar was used with the template to guarantee a little extra room.

Throughout the trench, a metal support that ran between the trench walls and about 10 inches off the trench floor was installed every 3 meters. This support was used to carry the utility pipes that ran from the luncheonette to the gasoline pumps. After the frame installation, the trench walls were layered with ½” of waterproof mortar. The floor of the trench was then lined with a few inches of concrete. Bar grating, made off-site, was put in place. Soil was back-filled behind the trench walls and tamped into place. Paving stone was replaced in the sidewalk areas. Alongside the trench in the parking area, a ½ meter concrete border was installed to give additional support to the trench.

The process used in Brazil for this trench installation was much more labor intensive than we would use in the United States. We probably would have had a backhoe dig the trench. Gravel would have been poured in the trench and compacted into place. A former system, such as EconoDrain, would have been installed to form the trench shape, and a ready-mix concrete truck would have been brought in to supply the concrete. The Brazilian project probably took 1 - 2 months to perform. In the US, this same project would have been a week, at most.

Send your comments or questions about this article to Michael@trenchdrain.biz.

This article is devoted to one of the NDS catch basin products called the Next Generation Basin or 1200 NGB. The 1200 NGB is a 12” x 12” catch basin that is unique because it allows you the flexibility of adjusting the invert elevations of the catch basin without changing elevation at grade (at the grating). No other residential grade catch basin has this feature. There are other neat features, as well.

 

      

 

The 1200 NGB basin also gives you an option in bottom discharging. In the bottom of every basin is an adapter knock-out (similar to the plug side knock-out), which allows the attachment of solid PVC pipe that feeds your drainage system. By attaching the bottom outlet to a perforated pipe, storm water can be used to recharge the ground water and create a leaching system. Small “weep hole” knock-outs are also located in the corners of the basin for those who are 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 a maximum amount of storm water to be put back into the ground. As the ground becomes saturated, excess water would reach the pipe elevation and then be taken away in the drainage system. Though this option maximizes the water that remains on site, it is not the best option next to home foundations.

One of the best things about the 1200NGB system, though, is the amount of grating options that are 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 black plastic grating (left) and the standard slotted cast iron grating (right).

Other ornamental cast iron grating options are available through IronAge Designs. Below are four gorgeous patterns that are popular in patio and downspout catch basins. Clockwise from the upper left, the pattern names are Sun Drain, Locust, Interlaken and Oblio.

These grates shown to the right 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. At the top left, 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. 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. The Interlaken Grate on the bottom right has a beautiful yet strict design; it must be a representation of the solid form of earth.

All of these products are available from www.TrenchDrain.Biz. Call toll free at 877-570-2333 or email your inquiry to sales@trenchdrain.biz.

In a previous article, I introduced some simple catch basins and their applications in yard and residential roof downspout drainage. Products by National Diversified Systems (NDS) were presented. In this article, we will look at downspout catch basin installation and highlight two square NDS catch basins.

Catch Basins and Water Quality

 I like to think of a catch basin as the “first line of defense” in cleaning up rain water and drainage pipes. It is common for homeowners to put their downspout water into a pipe that then travels out to the street or a back yard location. This often leads to clogged drainage pipes. Over time, leaves, sticks and sand particulate from roofing shingles will build up in the pipe to gradually reduce drainage efficiency. A catch basin helps to reduce this problem in two ways. First, the grating that covers the basin filters out the coarse debris that finds its way through the downspout, thus “catching” the biggest contributing factor to clogged drain pipes.

The second way of cleaning the water is the catch basin sump. Finer particles that pass the grating are “caught” in the sump portion of the basin. The sump is a small water reserve that is just below the exit pipe (invert out) of the basin. As suspended particles are first entering the basin, they must pass a swimming test. If they are able to enter the sump portion of the basin and “float with the current” to the exit pipe, they win. If they are too heavy or the water is too slow, they will sink to the bottom of the sump and be left there for later removal. The particles that generally “pass” the sump test are light organics and fine silt and clay sized. The particles that get trapped in the sump need to be cleaned out periodically. (So, check your sumps!!) Also, the deeper or wider the sump, the more difficult it will be for the particle to “swim” to the exit pipe.

Catch Basin Installation

That’s the theory. Let’s talk about installation. I’m going to show two methods that involve installing catch basins in concrete: the Single pour and the Double pour methods. I always like to place drainage products in concrete because of a number of reasons.
1) It adds strength to the drain, especially if it is made of plastic,
2) It anchors the drainage product to the ground and reduces “floating”,
3) I like the look of a concrete apron around the drain and feel that it helps direct the water to the drain,
4) And lastly, I like working with concrete.

Single Pour Method

The single pour method involves setting a catch basin in a form and making a single concrete pour to form the casing. For demonstration purposes, I’m using a NDS 900 Catch basin with a single outlet. The 900 series catch basin is a 9” x 9” basin with a built in 2 inch sump. When you order this basin, you need to know what pipe size you are using to evacuate the water because you will have to order a pipe adapter to insert into the outlet of the basin. (Note: all larger NDS catch basins will have this feature.)

Basin Install Hole

The next step requires setting the basin, connecting the pipe to the drain and building a wooden mold that will form the concrete casing. I was sloppy with this installation. I admit it. Normally, my work has symmetry. In this case, I never centered the basin properly within the mold. But, you will see soon that this can be made to look good. You can see that I used metal “pins” (or spikes) that were hammered into the ground which hold the wooden form into place. The pins have holes in them which allow me to hammer nails through them and into the wooden form. This is how the mold is held rigid against the earth. Also, the inside of the mold was lubricated with an oil to help in the release of the mold from the hardened concrete. Many products are available on the market to provide this release. However, an oil and kerosene mixture will work, as well as, plain ol’ Vaseline.

Pouring the concrete in the mold is the next step. I used a 50 pound sack of concrete purchased from a local home improvement store. After mixing to the proper consistency, I placed the concrete in the mold and used a metal rod to poke the wet mixture and ensure that air bubbles were not trapped. I want to point out here that I didn’t have concrete under the catch basin. I actually had a large stone. The purpose of the concrete was to provide a “shell” around the catch basin which could provide additional drainage surface for downspout water to collect prior to entering the basin.

Basin Install Pour

 I stripped the mold after I let the concrete set over night. I trimmed away all tramp rock, dirt and wood to leave behind a clean, crisp concrete cube. I want to point out here that I centered the drain under the downspout. And, because the downspout pipe was so close to the wall, I opted to rest the catch basin against the house. I could have put a curved spout on the downspout and brought the catch basin 3 inches away from the wall. In this case, I would have had a concrete section between the house and the catch basin. Perfect symmetry would have been achieved!!! (I should have done that.)

Basin Install Stripped

 Next, I made it look purdy! (Some people would prefer “pretty”.) I packed clean soil around the concrete. I put a bead of caulking between the wall and the concrete casing to keep water away from that spot. I added a little downspout extension to accurately direct the water. And, I mulched the area. Doesn’t it look nice? Even with the poor symmetry of the concrete, it looks charming. Even still, I learned from this experience and I will do a better job on the next installation.

Final Basin

 Double Pour Method

The double pour catch basin installation method utilizes two concrete pours to set the drain. The first pour is made around the drain to stabilize it, and the second pour, made after the first has hardened, is to complete construction of the larger drainage surface.

The double pour method is generally used when you are placing the drain within a large open area or within a larger form. For instance, if you are making a new concrete driveway, there will be forms defining the edges of the driveway. It would be unnecessary to build a perimeter form around your catch basin or driveway drain. You would merely set your drain in a location at an elevation that would facilitate the drainage of the driveway. And, after setting up the drain pipes and any structural steel, the whole driveway would be poured at the same time.

However, a catch basin will try to rise out of the wet concrete as would a boat on water. Lightweight objects will become buoyant and sway or float due during concrete placement if not locked down. A small amount of concrete poured at the base of the drain will provide the stability needed for the final pour. And prior to drying, the elevation and alignment can be “fine tuned” in preparation of the final pour.

In the example that follows, I used a 12” x 12” catch basin made by NDS. This product, NGB1200, is promoted as the Next Generation Basin. Its walls are constructed in a manner which allows you to adjust the depth of the sump area at the base of the basin. Walls are constructed either with an invert opening or with a solid wall. The following picture shows installing and trimming a solid wall section of the basin.

Install Closed End

 For this installation, I decided to have a shallow sump. When installing the open invert wall section, I trimmed the section to give only a 1” deep sump. A pipe adapter was required for me to attach my 4 “ S&D pipe. This NDS fitting (#1243) locked into the side of the open basin wall.

Install Open End

 This basin was to be placed at the base of a downspout adjacent to a driveway. The drain was to become a part of a new sidewalk next to the driveway and house. A hole was prepared to the proper depth. The existing driveway and house foundation formed borders that flanked the drain.

Install Hole

 Next, a small amount of concrete was placed in the hole. The catch basin was set in the hole and filled with stones to help keep it from floating. More concrete was poured around the basin to ensure that it would be locked into place once dried. While the concrete was still wet, the basin was adjusted to the proper elevation and symmetry with the driveway and house.

Install 1st Pour

 After the first pour had hardened, it was time to pour the sidewalk. The stones that were originally put in the catch basin to stabilize it were left in place during the 2nd pour. Once the sidewalk had been poured and was dry enough to walk on, the stones were removed and the catch basin was cleaned of stray concrete. As a final touch, a cast iron “Sun Grate” by Ironage Designs was then installed to complete the project.

Sungrate Installed

 Final Notes

Catch Basin sizes and styles vary with application and drainage requirements. Residential catch basin range in size from 6” diameter garden drains to 24” x 24” yard drains. A wide variety of grating options are available. Plastic, brass, cast iron and chrome grates are designed to meet the cost or aesthetic requirements of your drainage project.

Trenchdrain.biz is an authorized dealer for NDS drainage products and can offer advice in making catch basin selections. In addition, we carry Ironage decorative grating products that fit many of the NDS drainage products.

 Contact at 610-638-1221 or email Trenchdrain.biz