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 Â½” 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.