Questions and Answers
What's an Eljen Prefabricated Composite Drainage System?
An Eljen Prefabricated Composite Drainage System (EPCDS) consists of a high compressive strength waffle-like plastic core protected by a special drainage fabric. Eljen's standard plastic core has a compressive strength of 4300 PSF and has a rate of flow of 15.9 GPM per lineal foot of 12” material at a 1% slope.
How does an Eljen Drain work?
EPCDS allows water or gas to be pressed through a scientifically designed drainage fabric into the plastic core where it is transported by gravity flow away from the area. The Eljen Drain all but eliminates hydrostatic build-up. It's a simple system but it works!
What does an Eljen Drainage System replace?
An Eljen Drainage System replaces drainage materials such as gravel or stone, graded aggregates, sand blankets, filter fabrics and the like. It is by far easier to install then any other type of drain using rock or filter fabric.
Do I need a drainage pipe?
An Eljen Drainage System can be used with or without a drainage pipe. Pipe size is dependent on how much water or moisture it to be removed. If drainage pipe is used surface inlets may be added to certain Eljen Styles.
Is there a choice in Eljen Drainage Systems?
The choice is yours! Eljen has the flexibility to offer you many different styles of EPCDS. Core strengths from 4300 PSF to 15120 PSF are also available. Both single and double cores are available. Eljen Drainage Systems are offered with or without a sewn fabric sleeve for drainage pipe.
What sizes are available?
Eljen Drainage Systems are offered in ten standard styles and hundreds of standard sizes. The sizes range from 2” to 60' in height. Any height over 5 feet makes the maximum length five feet due to size limitations of forming machines. Lengths are normally 5' to 100' long depending on style but may be ordered as required if necessary. In addition Eljen will manufacture a full range of custom styles and sizedto your job specifications.
How does the Eljen Prefabricated Composite Drainage System (EPCDS) differ from other drain products?
Eljen EPCDS is manufactured in panels that are completely prefabricated all ready covered with geotechnical drainage fabric to any height specified and any reasonable length. Other drainage products are either 4'x8' panels or are in rolls of 4'x100' and generally have a geotechnical filter fabric only on one side. Other drainage products bond the filter fabric to the cuspations while the Eljen EPCDS drain does not.
Why can Eljen EPCDS protect against product failure and installation errors that can occur with other drainage products?
Other drainage products with fabric on one side require overlapping of core and fabric during installation, which may not be done properly. Eljen EPCDS is completely wrapped in fabric; no overlapping is required. The others can be installed backward; this can not happen with Eljen EPCDS. Frost or high pressure on the back side of one-sided drains may crush them.
Why can material cost of Eljen EPCDS be lower than other drainage productseven if Eljen EPDCS square foot price
may be higher?
Because other drainage products may require overlapping on all sides, cutting to size, large amounts of material, and a lot of other labor. There may be a loss of 25% of time and material. There is no overlapping and no loss of material and time with Eljen EPCDS drains. Exact cost can be determined in advance with Eljen.
Why is it important that the drainage pipe at the
bottom of Eljen drainage products to be protected?
Eljen series EL00500, EL00700 etc.
If the tubing is not protected, soil intrusion will reduce or stop the product's effectiveness. In the Eljen EPCDS drain the drainage pipe is inserted inside the fabric to completely protect it and to uniformly control the access of water into it. No other drainage product provides this degree of protection. Other drainage products require that workers give special attention to the installation, which may or may not be given. Due to Eljen's design the drainage pipe is straighted invariably making installation fast and easy.
Why is installation time shorter (for walls and slopes) when Eljen EPCDS is used compared to other drainage products?
The Eljen EPCDS has two tie straps on each panel with are easily and quickly attached to the wall or slope so that the panel is held in to place before backfilling. Other products require nails to be driven through the material or for the product to be glued to the wall. Eljen EPCDS drains are completely prefabricated less any drainage pipe. They are complete with overlap flaps for connection. Extra drainage fabric is included on all Eljen EPCDS drains to facilitate on site changes.
Why is the Eljen EPCDS lower in cost for trench installations than other drainage systems?
The Eljen EPCDS can be assembled on the surface, perforated drainage pipe is inserted, and the whole drain then can be lowered into the trench as a single unit. It is held against the up-hill side of the trench by the tie straps and tied to a stakes on the ground surface. Other drain products require workers to be in the trench to overlap the core and fabric and to cover the tubing at the bottom. Since workers must be in the trench, OSHA regulations require the shoring of these trenches, with takes additional time and is costly. No workers need to go into the trench when the Eljen EPCDS drain is used.
Why does the loose or not glued fabric on the Eljen EPCDS
drain not get compressed down into the channels of the
cuspate core during the backfilling of the soil and reduce
the flow of the groundwater?
Due to the close spacing of the Eljen core's cuspations, there is very little pressure on the fabric. Natural soil bridging from one cuspation to the other occurs. The soil that is backfilled bridges across the short distance of the cuspations. Therefore, the fabric is not pressed into the channels and there is no reduction in the flow. Eljen drainage fabric is semi-ridged adding to the strength.
Why is the claim that bonding the fabric to the cuspations of the core will prevent the fabric from closing off the channel of the core during backfilling, not correct?
Because of the wide spacing of the cuspations in many of the other drainage products, the bridging of the soil does not occur as it does with the Eljen EPCDS drain. The pressure of the backfill on the fabric causes the hot melt adhesive that held the filter fabric taut before backfilling, to elongate into the cusps. In some cases the adhesive is biodegradable, allowing the filter fabric to sag into the cuspations in the core.
Why is the two-sided Eljen EPCDS core better than a one-sided core drainage product for waterproofing membranes?
Installing a drainage system, using a one-sided core, against a water-proofing membrane, wall, or a foundation wall, can cause problems. Should subsurface water get between the core and the membrane, the hydrostatic buildup can cause the waterproofing membrane or wall to rupture. This cannot occur with a two-sided core drainage system, because the water will flow down the channel and there will be no hydrostatic pressure buildup. Tests have proven that the pressure of the two-sided core's cuspations on the waterproofing membrane has no damaging effect on the waterproofing membrane. You basically have a wet side and a dry side and no pressure to push the water through the wall.
What makes Eljen EPCDS superior to conventional rock
and pipe systems?
• Larger area of Eljen EPCDS drainage surface allows more water to penetrate the surface.
• Reduces hydrostatic pressure.
• Drains groundwater faster than the conventional aggregate drains with no restrictions.
• Can be installed faster than other aggregate or non-aggregate drain products or fabric wrapped gravel, thereby lowering installation costs.
• Provides drainage for many applications because of its great compressive strength and many configurations.
• Easily maintains a constant grade.
• Easy to assemble and install.
• Smaller trenches are required.
• Less backfill
• Minimal compaction required
• Little or no excavated material to dispose of.
What makes Eljen EPCDS superior to conventional rock
and pipe systems?
• Larger area of Eljen EPCDS drainage surface allows more water to penetrate the surface.
• Reduces hydrostatic pressure.
• Drains groundwater faster than the conventional aggregate drains with no restrictions.
• Can be installed faster than other aggregate or non-aggregate drain products or fabric wrapped gravel, thereby lowering installation costs.
• Provides drainage for many applications because of its great compressive strength and many configurations.
• Easily maintains a constant grade.
• Easy to assemble and install.
• Smaller trenches are required.
• Less backfill
• Minimal compaction required
• Little or no excavated material to dispose of.
For additional questions. Contact us at…
Tel: 303-595-8722
Fax: 303-893-9161
E-mail: Masterdistinc@eschelon.com
