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Trench Drain Supply - 5621 Raby Road - Norfolk, VA 23502 - Sales 877-903-7246 Ext 1
Trench Drain University
Trench Drain Frequently Asked Questions

General Questions

Q: What is "Email a Quote"?
A: Our "Email a Quote" option on checkout allows a customer who is looking at a trench drain to quote themselves. There is no obligation to Email a Quote, and we do not require any payment information. Contact with us can then be made if there are any questions, or if a contractor discount is needed. It is an excellent way to have on hand the quote needed while the purchasing decision is still pending. The quote has "25xxxxx" quote number at the top and this number can be referenced throughout the buying process. One the purchasing decision is made, go to our Direct Payment page and pay using any major credit card, or call us for payment.

Q: When I order a complete trench drain kit, What comes with it?
A: Trench Drain Supply Kits are shipped complete and ready for installation. They include numbered channels, grates, solid end caps, outlet end cap, bottom outlet, and grate locks. The exact end cap assortment locks vary from type to type, so check the description. The only other option needed are installation brackets.

Q: What are installation brackets? Are installation brackets necessary and do I need them?
A: Installation brackets suspend the trench drain for installation. The brackets go at each end, and under every joint between sections, and allow rebar to be run vertically. This allows the rebar to be driven into the ground to suspend the trench drain and allow for concrete to flow around the trench drain when poured. Installation brackets allow for a significantly easier install, however we find that experienced concrete contractors may use the concrete pier installation method and save on the cost of the brackets. We highly recommend brackets, but they are not required.

Q: I am wondering if this product is the right one for what I need?
A: We understand that our wide variety of trench drains can lead to analysis paralysis. Please check out our Buyers Guide for help. Many factors go into the decision for trench drain. Our professional sales staff would be happy to go over your requirements and provide you with a no obligation custom quote for your job. Please contact us.

Q: I have a plan and would like to email to you for pricing. Is that possible?
A: Yes. We can review your plan and provide a price. Please email to our sales Contact. Please be sure to give us a general idea of the scope of the job, and any specified trench drain requirements. Also, please make sure that the slope direction and outlet location is specified on the plan. We can also do a plan if needed.

Q: Not aware of "1/2M". What are the dimensions in inches?
A: : 1M and 1/2M are abbreviations for one meter and one half meter. Many trench drain manufacturers are European based and provide their products in meters. A meter is 39.37 Inches long or a little longer than a yard. A Half Meter is 19.67 inches long. The easiest way to figure out how many meters are needed in a job is to take the total feet x 12 to get total in inches and divide by 39.37 to get total number of meters. You would ROUND DOWN to last full meter. For example a 25 foot run would equal 300 inches divided by 39.37 to get 7.62 meters. Thus a 7 meter order would be appropriate.


Q: What is slope?
A: Trench drain comes in flat or presloped. Every make and model comes in flat, but not all types have a slope option. Flat (or Neutral) trench drain means that the bottom of the trench drain channel is the same depth on either end of the run. Water will flow to the outlet on a natural basis. Preloped means that the bottom of the trench drain becomes gradually deeper as the run progresses. This allows the water to run downhill to the outlet. The way this is acheved is each channel in the trench drain run is made differently. Each channel has a number from 1 (the most shallow) to 10 (or 25 or 30 or 40 depending on manufacturer and style). When installed the channels are connected in order.

Q: Does my system need to be sloped?
A Flat trench drain (all neutrals) are frequently used when the installation has a pitch. They can also be used on a flat installation where it is better to have debris settle into the channel for cleaning rather than going out of the outlet. Unless there is specific flow requirements, a flat trench drain on a level grade will drain properly. Water always seeks its lowest level.

Q: Do I have to choose individual sections for my order?
A: No. In most cases we will choose the channels most appropriate for your installation. For flat orders, runs do not matter as they can be connected any way needed. For sloped orders, the runs are critical. On a single run order, we assume each run slopes to the end. On a multi run order, we assume each run slopes to the end and that they do not connect. Please let us know IMMEDIATELY if you need a different slope configuration, or if the runs connect. Other slope configurations include slope to the center, slope away from the center, Deeper than standard, or shallower than standard. If the runs connect then a drawing may be needed. Please contact us.

Load Rating

Q: What is a load rating?
A: There are two main grate definitions in the trench drain industry to help specifiers select the appropriate grate. The load raing is the amount of weight a grate can take. The DIN 19580 Standard is designed to meet the following loading Classifications in a static condition

Load class A 3,372 Lbs per foot (15 kn). For pedestrian foot traffic only.
Load class B 28,100 Lbs per foot (125 kn). Light Pneumatic Tire traffic only.
Load class C 56,200 Lbs per foot (250 kn). Commercial Applications.
Load class D 89,920 Lbs per foot (400 kn). Pneumatic forklift traffic - H20 Load Rated.
Load class E 134,800 Lbs per foot (600 kn). Solid Tire Traffic patterns. Solid tire Forklifts.
Load class F 202,320 Lbs per foot (900 kn). For Airport Traffic.

Q: What are the AASHTO Transportation Classifications
A: The American Association of State Highway and Transportation Officials (AASHTO) "Standard Specification for Highway Bridges" defines H20 loading as tow axle truck with a maximum dual-wheel load of 16,000 pounds.

HS-20 loading is defined as a tractor truck with a tandem axle semi-trailer with a dual-wheel load of 16,000 pounds.

Q: I neeed H20 loading. We will be driving front end loaders over it and large forktrucks. Is this correct?
A: It depends. If the forklifts have pneumatic tires then H20 (or D Class) grates would be acceptable. If the forklifts have solid tires, then a Class E Grate is appropriate. In most cases we would recommend choosing the class E. The difference in price is not that great and we always advise to go with the highest class a budget would allow. The occasional extra heavy vehicle or wheels will do damage to an under classed trench drain grate.

Q: I am trying to determine what grating and capacity of drain I need. Primarily forklift traffic with 5,000 lb rated lifts and foot traffic
A: It is less about the weight of the forklifts but the type of tires involved. Solid tire forklifts require E Class, while pnuematic require D Class. The capacity of the drain is not related to load class, however, the wider the trench drain the heavier the grates have to be to accommodate the load class and the greater the cost.

Q: What is Safe live load?
A: The maximum safe live load is calculated by dividing the load at failure by two.


Q: I'm looking for trench drain that is ADA compliant. What do I need?
A: The Americans with Disabilities Act (ADA) stipulates that the slot width be limited to 1/2" or less on gratings and walkways and elongated slots must be placed longitudinally so they are perpendicular to the dominant direction of travel. ADA compliance is all about the grating needed for a trench drain.

Q: What is Heelproof? Do I need it?
A: Heelproof is defined as slots or perforations that are less than 1/4" in width or diameter. All Heelproof grates are ADA compliant, but not all ADA Compliant trench drain grates are heelproof. Normally heelproof grate are perforated (round holes set in a pattern). Heel proof grates are needed in front of exterior doors. They are also required in any public building that has foot traffic. Since the holes are small, they do not have the ability to drain large amounts of water. This factor should be taken into consideration.


Q: Do I have to install in Concrete? / How much Concrete is required around the Drain? / Can I install in asphalt or pavers?
A: Proper trench drain installation requires it to be installed in concrete. A minimum of 4 inches around the entire trench drain is required. More than 4 inches is required to achieve greater load ratings. Please see manufacturers installation guide. Installing in any other material without concrete is not advised, and can lead to failure of the trench drain to hold the loads, or cause the trench drain to rotate.

Q: Can I cut channels to size?
A: Although most trench drain channels and grates can be cut in the field, we do not recommend cutting if it can be avoided. Most manufacturers provide a half channel and this should be the smallest piece in the run. One reason we do not recommend cutting is if cut smaller than a half channel, the grates may not be able to be secured in the channel by locks. Also the smaller pieces are hard to align properly when pouring and are much more subject to breakage. We recommend a shorter run and centering the run with concrete on each side. It gives a better look.

Q: What size opening do I need to cut in the drive to accept this drain system?
A: A minimum of 4 inches on each side is needed to allow for proper concrete installation. So for a 4 inch trench drain, a 12 inch cut will be needed for installation.

Q: can I cut a drain trench out of the blacktop where it meets the concrete put this drain system in and backfill with gravel/crushed rock or does it need to be cemented in?
A: A cut can be made in the blacktop, but the trench drain must be cemented in for proper installation.

Q: Do the channel joints need to be sealed?
A: No. once the concrete is poured, the concrete itself acts as as the sealer. The joints can act to help with expansion and contraction, but they should NOT be used as an expansion joint. Please see manufacurers instructions as to proper use of expansion joints in an installation. In some applications, sealing may be desired. In that case, joints can be sealed with silicone caulk.

Q: How do you secure the grate down? / Do they interlock with each other? / Give me some idea how you install these grates?
A: Almost all trench drain grates can be locked down. This prevents the grates from dislodging when vehicles or foot traffic is going over the grates. The most common grate lockdown method is a lockbar that spans the channel. This bar fits in grooves in the channel. The grate is then bolted down through a hole in the grate with a bolt provided with the lock. Larger cast grates are normally bolted down on all 4 corners. Manufacturers have come up with many patented different methods to lockdown a grate. Names such as Starfix, Profix, Clipfix, Quicklock are all different methods to lock a grate. Thus, if one is trying to replace a grate in an existing system, making sure the correct manufacturers grate is used with the right lock is critical.

Q:How does the unit actually drain? / Can the bottom outlet be placed anywhere in the unit to allow for drainage (ideally allowing the placement to be directly above where the drainage system in the floor starts)?
A: In some makes and models, a bottom outlet can be placed on any channel number. On other styles, bottom outlet cutouts can only be found on channels periodically down a run (such as on the 5, 10, 15 channel numbers). The bottom outlet can be placed over the drain but you would need this to be the lowest point in the run for proper drainage. If this drain was in the middle you would need a drain that "slopes to center". This does not necessarily mean the drain has to be exactly in the center, it just means that the trench slopes up from the drain on the right and left. For example, if one has a 20 foot run and the drain is five feet from the end, the trench drain will slope down 15 feet on one side and slope down five feet on the other to meet at the drain. Please contact us and we can provide a drawing outlining the channel numbers needed.

Q: I'm actually curious about the end cap (the blocked off end), not the outlet. Are those available for all sections (1, 2, 3, etc.)?
A: Most trench drain systems come with universal end caps. These end caps are made with precut perforations at each section number height. This allows them to be used on any channel number. The excess is snapped or trimmed off at the correct height.

Q: Hi there I ordered 4" glass fiber polyester trench drain kits, do you have generic installation instructions you could send me?
A: Yes we have manufacturers installation insructions for each system as well as generic installation instructions. Please contact us and we will be happy to provide.

Q: Will the grates rust?
A: All grates made from iron rust over time. These include galvanized steel and ductile iron or gray iron. Stainless steel trench drain grates do not rust but are much more expensive, and plastic or nylon grates obviously do not rust. For galvanized steel grates, the galvanizing process hinders rust for quite a bit of time. Galvanized grates can go years before rust becomes apparent. Although they have the potential to rust in the future galvanized grates usually have the best initial price.

Ductile iron grates and gray iron grates on most all standard trench drain systems are painted. This paint hinders the rust process, and most grates look great for years. Over time and use, the paint is worn off and rust does appear. The advantage with this type of grate is that it can be repainted and maintained for years of quality service.

Q: I am looking at cast iron (raw) grates, Will they rust?
A: This type of grate is supposed to rust to a nice chocolate brown patina.

Our vendor Iron Age provides an excellent description of this process...

“Rust” the Oxidation of Cast Iron Metal
Cast Iron goes through a process of oxidation, more commonly known as “rust”. Most metals, with the exception of gold, go through some form of oxidation. This oxidation process creates a tightly adhering iron oxide coating known as the Passivation Layer. The Passivation Layer actually protects the bulk iron from further oxidation. In other words, once the Passivation Layer is created the oxidation slows dramatically and the iron remains intact for a very long time.

On the whole Iron metal is relatively unaffected by pure water or by dry oxygen.

Oxidation as a Patina
This Passivation layer is often referred to as a Patina. Many metals create a Patina, the green patina that forms naturally on copper and bronze is known as verdigris and consists of copper carbonate. Think of the Statue of Liberty’s green color. The patina on cast iron is more chocolate brown in color.

The Passivation or Patina Evolution

The oxidation process begins on contact with water and goes though an evolution of Passivation or Patination. First the iron turns bright orange for a few months then slowly will turn chocolate brown in color. Over time, perhaps a year depending upon the environment, they will look like every other cast iron manhole cover or drain grate that you see in the street.

When traffic wears on iron the finish can take on a burnished look, think of manhole covers you see in high traffic areas. Unlike steel the Cast Iron will not flake away. The navy has made ship anchors out of cast iron, which can last for decades in a raw state. Most of the casting you see in the street such as manhole covers are made of cast iron and are very durable.


Q: How long will it take from placing an order until delivery?
A: We stock a large majority of the main trench drain manufactures in our warehouse. We stock all products that are marked bestseller. If is is a standard product or bestseller, we normally ship the sale or next day. We ship the majority from Virginia, but we do have warehouses around the country. In general, shipping time is 1 to 2 business days or less east of the Mississippi River and 3 to 5 business days west of the Mississippi River.

Q: I live in Oakland CA, do you have any local distributors? / Do you have any suppliers in or near Washington, DC?
A: We do not have local distributors, but we can ship from warehouses around the country. If you have special requirements for delivery speed, please let us know. Our normal delivery times are the best in the industry, but we may be able to make even faster accommodations if needed.

Q: Is shipping included or how much is shipping to Roseburg, Oregon, and is the pricing on your website the correct pricing?
A: We do charge for shipping. Our Cart provides an estimate for shipping that will be the actual amount charged. We understand that the big thing today is to offer free shipping. Why do we charge shipping? In order for us to offer the absolute best prices, we have determined that we need to add a shipping charge. This makes it fair to our customers who order a small amount and to the customers who need to order a large amount. Due to the weight and size of trench drain, shipping charges are a factor in total price and should not be hidden. We have made every attempt to get these charges to accurately reflect actual charges.

Q: What would be a contractor price I am a licensed plumber in AZ.
A: We do offer a contractor trench drain discount program. Please check out our Contractors Page and fill out the information. A discount code for orders will then be provided. For faster service, please contact us and we will get the appropriate information to provide a contractor price. If products are already in the cart, use "email a quote" and checkout. Then contact us and we can apply the discount to that quote.

Q: Need to know your process for using a tax exemption number.
A: Our main warehouse is in Virginia. All Virginia sales are taxable unless an ST-10 Virginia Tax Exempt Certificate is provided. In addition, if we ship from one of our other warehouses, a tax exempt form may be needed. We will email if this is the case. If you are tax exempt, and have a certificate, we will always accept it and put on file for the current and future orders.