• Freerest
  • Clients


A trench drain is a specific type of floor drain containing a channel-shaped body that is installed below ground.  Known by various other names like channel drain, line drain, slot drain, linear drain or strip drain, a trench drain serves to quickly drain surface water or to contain utility lines or chemical spills.

Trench drains have a solid cover or grating that is flush with the adjoining surface.  The channel is commonly formed from concrete in-situ and may have polymer- or metal-based liners or a channel former to aid in channel crafting and slope formation.  Characterized by its long length and narrow width, the cross-section of the drain is designed to suit the maximum flow volume anticipated from the surrounding surface. Channels may range from 1 inch (25 mm) to 2 feet in width, with depths that can reach up to 4 feet (120 cm).

Trench drains are commonly confused with French drains and slot drains.  A French drain consists of a perforated pipe buried in a gravel bed; it is used to evacuate ground water.  A slot drain, on the other hand, consists of a drainage pipe with a thin neck (or slot) that opens at the ground surface with sufficient opening to drain storm water.

Based on the way they are formed and their installation methods, there are four common types of trench drains: cast-in-place, pre-cast concrete, liner systems and former systems.  Newer stainless steel drains are available for residential and commercial shower installs and more commonly called channel drains.

The original standard for trench drain systems, this concrete trench is formed in the ground using wood forms, reinforcing bar and manual labor.  This is by far the most labor-intensive of all trench drains.  Material cost depends on the width of the grate used in the trench.  However, labor and cost problems can be overcome by the use of modular trench drain systems.  These allow the drain pipe to be connected anywhere along the trench, giving the builder and plumber more freedom to place the services, reducing construction time and costs.  Achieving a curbless or hobless entrance for special needs access is more readily achieved with a modular system.

Waterproofing is possibly the most critical aspect of integrating a channel/trench drain. There are two approaches to waterproofing.  First is to develop a proprietary method where the waterproofing and trench drain are a kit.  Second is to separate the waterproofing and trench drain.  The first method has the benefit of an all-in-one solution, but the downside is cost and limitation of the system in varying applications.  The second method is generally safest as the waterproofing is completed using established proven methods that most building contractors are familiar with.  Another benefit is that when the waterproofing is a separate item, all methods of waterproofing can be utilized.  This will allow a modular system to be used in many applications such as pools, balconies, thresholds, pedestrian areas, public areas, and essentially most wet areas where a waterproofing system is required – be it on ground or above.  Stainless steel trench drains can also be installed in a shower or bathroom and in commercial locations like hospital rooms, changing rooms and operating rooms.

Former systems
This installation method results in a cast-in-place product but without the hassle of making the form.  Rather than wood, the forms are made of lightweight expanded polystyrene (EPS) or cardboard.  The forms attach to a prefabricated frame and grate system that can then be easily set in the trough and aligned for the pouring of concrete.  Like the cast-in-place method, the form is removed after the concrete has dried.  The real savings with the former method is in the time required for making and setting the form. The efficiency of the former system helps speed up the installation thus reducing labor costs.  One downside to the former system is the waste generated by the disposal of the EPS and cardboard, although the cardboard is recyclable.

Pre-cast concrete
Here, trench drains are made in a factory that specializes in making concrete shapes.  The channel pieces range in width and length.  Larger channels require heavy equipment to move them, but most channels can be picked up and moved easily by hand. The channels are formed in large metal forms that usually have a pre-determined channel width, depth, and slope.  

Like in the cast-in-place method, a metal frame is attached to the form and concrete is poured and finished in a factory atmosphere.  The advantage to the pre-cast trench drain is big time savings at the job site.  Pre-cast trench drains made of a polymer concrete are also more sturdy and reliable than cast-in-place trenches. Once a trough is dug, the pre-cast trench sections can be installed and quickly be put into service through numerous methods.

Pre-cast trench drains generally come in 4-inch widths but can range anywhere from a 1-3/4-inch slot to 2-inch-wide channels with grates, and up to any size imaginable through custom trench drain divisions.  A home owner could consider a pre-cast trench for a landscaping project as there are many pre-cast trench drain systems being manufactured specifically for the residential market. A person generally can go to a pre-caster or a distributor and buy 50 feet of trench drain out of the yard; the cost of the material to create the trench drains can be more expensive than simply using cast-in-place systems, however the money saved through installation, maintenance, and longevity heavily outweighs those costs.

Linear systems
The popular trend in trench drains is linear systems.  Made from materials such as polymer concrete, fiberglass, structural plastic and steel, liner systems are the channel and grate components that are assembled in the trench and around which concrete is poured to form a drain system.  By themselves, these liner systems do not have the strength and integrity to hold up under the physical requirements needed for the drain. A concrete (or asphalt) drain body is required to encase the channel to give the channel compressive strength and rigidity to ensure the drain will be able to withstand the traffic load it was designed to handle.

For more answers to your questions regarding trench drains, contact Freedom Restoration at 410-451-7110 or click here.







Popular Posts

    Commercial Property Executive

    Co Star Group





Our Guarantee:

No other contractor in the area will respond more quickly, follow through more accurately or treat you more professionally.


Copyright © 2010 FREEDOM RESTORATION, LLC  |  Designed/Maintained by RQue Royal Design