Improper Drain SelectionAnother improper drain selection situation is when you install a drain that will see a larger amount of water than it can handle. Again, the drain can be installed perfectly, but if the drain is overrun with a deluge of water, it is not serving its purpose. It is best to do a quick flow calculation prior to selecting your drain, just to double check that you have a drain that can handle the water flow anticipated. Contractors and homeowners sometimes focus on appearance when installing trench drain systems. However, if the wrong drain is installed for the specific application, you have the potential to experience a system failure. One such example is when a plastic drain is installed in an area that involves fork truck traffic. Some drains are meant for light duty and residential applications only. Plastic drains from the big box stores such as Lowes, Home Depot and Menard’s are meant for use in a patio or driveway with little automobile traffic. The light duty construction of these channels will have a tendency to break under heavy loads or due to the freeze-thaw episodes seen in the winters up north and extreme heat in the south can cause warping. For applications where a drain is going to see repeat traffic from automobiles, delivery trucks or fork trucks, a heavier duty drain is required. Drain bodies made from HPDE or polymer concrete with grating recesses that are supported by concrete (i.e. the grate is wider than the channel opening) are recommended. More preferable would be a channel body capped with a metal frame and heavy-duty grating.
Improper Grating SelectionEven an incorrect grating selection can lead to trench drain problems. The most common problems arise when the grating either has insufficient load rating, experiences extreme temperatures or insufficient chemical resistance. Load rating problems are common. Inexpensive grates generally have a lower load class rating. A grate with a Class A load rating is intended for pedestrian applications. In some cases, they can still fail due to lawn and pool furniture legs which can crush through the grates. They are sometimes incorrectly used where automobile traffic is frequent thus leading to grating failure. Unfortunately, we have seen instances where contractors or engineers chose a lower class grating to meet the budget of the project. Later, of course, it results in the owner having to replace the grates. This is the case with the example to the right where a winery installed stainless steel slotted grates with a Class A load rating. The application had required a grating with a much higher load rating. Stainless steel is already expensive, but the project owner settled on the cheaper stainless grates which couldn’t take the weight of pallet jacks and wine barrels. Needless to say, they later replaced the grates with reinforced stainless steel grates. This additional cost and downtime could have been avoided by making the right decision to use grates with the appropriate load rating for the initial installation. Insufficient chemical resistance is also a common example of improper grating selection. It is important to consider the quality of the water or environment that the drain is going to handle. Sometimes it just slips out of our mind. Also, it may be tempting to ignore the possibility of the drain seeing an aggressive environment which would force the consideration of more expensive, chemical and temperature resistant grating options. For those who live near the coasts of Florida, California or Washington, the salt water atmosphere plays havoc on cast iron and galvanized steel. Eventually, trench covers corrode and need replacing. For coastal environments, it is wise to consider a grade 316 stainless steel, HPDE or fiberglass product when possible. Likewise, in dog kennel applications, galvanized steel grating eventually corrodes from the animal urine and harsh cleaning chemicals. This leads to premature replacement of the grating. For non-profit organizations looking to cut costs, it is tempting to use a low-cost galvanized steel grate for the kennel application. It would be better in the long run to use the same recommended materials as coastal areas: stainless steel, perforated HPDE or fiberglass grating to avoid additional expenses later.
Most of the problems described in this post can be summed up as poor workmanship and poor selection. It is important to be sure the contractor installing your drain knows what they are doing. Is this their first trench drain installation?Ask how many installations they have done. Also, don’t necessarily leave it to the contractor to find you a drain. Let them know you don’t want the local big-box store drains which are often plastic, incorrect for the application or aesthetically displeasing. This will prevent further investment of time, money and frustration to the project. Contact the drain experts at Trench Drain Systems to help you with your drain selection. Take a look at our website trenchdrain.com or our online store trenchdrain.com/shop . Or give us a call at 610-638-1221, 8am – 5pm EST, Monday through Friday.