What is the approximate cost for the PaveDrain System per square foot (including labor, etc.)? What is the approximate cost of the material only per square foot?
Depending on location and project size a conservative installed cost of the PaveDrain System is $10-11 per SF. This typically includes an installed 6 - 12" layer of clear stone (#3, #57 (TBD) and 1-inch of #8). The installation of the PaveDrain blocks or mats will be around $2.00- $2.50 per SF. The materials cost will be $5.00-$6.00/Sft. Delivery will add $0.50-$1.00 per SF depending on the distance to the jobsite. Color blocks adds ± $1 per SF.
Does the PaveDrain System require maintenance?
Can a PaveDrain block be replaced if it is broken?
Yes. See Installation Guidelines for step by step instructions.
What is the projected amount of water that can be "held" in inches?
The PaveDrain block has been subjected to a strenuous testing regimen with different soil types including sand and clay base. During the testing a 7.6" rain event per hour did not yield any runoff until after 99 consecutive minutes of testing on a sandy base. The clay sub-grade did not yield runoff until after 42 consecutive minutes of a 7.7" rain event per hour. BOTH tests were on a 6" layer of #57 stone.
What is the percent void area of the PaveDrain block?
The arch comprises a 20% void area of a standard 11.9" x 11.9" x 6.00" PaveDrain unit.
How do PaveDrain blocks perform in Freeze-Thaw environments?
The PaveDrain System is based on articulating concrete block mats utilized for erosion control in the U.S. for more than 30 years. Its matrix of interlocking blocks provides a tremendous advantage during freeze-thaw conditions over traditional systems due to its flexibility, allowing minor freeze-thaw forces on the block itself. The concrete mix design of the block is derived from freeze-thaw tests (i.e. ASTM C1262) using time tested methodologies from other concrete products.
Can the PaveDrain System be snow plowed?
Yes. Please SEE THE VIDEO of the PaveDrain System being snow plowed in Bladensburg, Maryland. Additionally, all of the edges of PaveDrain blocks are chamfered so that no corners or edges are created. PaveDrain blocks struck by a steel snow plow blade have shown only minor chipping on the surface.
Can Salt be utilized for de-icing?
Yes salt can be utilized. However, following an extremely heavy winter in Bladensburg, Maryland, on the first large scale PaveDrain installation NO salt was utilized. Similar to other permeable surfaces, the PaveDrain System does not allow water to collect on the surface very long. The water drains off the surface of the blocks, down the sides and into the subgrade. Still to be researched is the effects of the negative air return provided by the arch and the difference in ambient air temperatures within the arch and above the block. This research will be completed in early 2012.
"After one winter our new PaveDrain parking lot used significantly less salt than or old asphalt parking lot."
Town of Bladensburg
"Responsible and Responsive Government"
4229 Edmonston Road
Bladensburg, Maryland 20710
Will the cable corrode and wear out?
The cable utilized is a polyester cable wrapped with a nylon sheath. It is highly unlikely that the cable will ever wear out. It has excellent resistance to most concentrated acids, alkalis and solvents. Polyester cable is impervious to rot, mildew and is not affected by continuous immersion in stormwater with salt. Polyester cables have been utilized in salt water environments on articulating concrete block mats in erosion control applications for more than 3 decades.
Can PaveDrain blocks come in different colors?
Yes. The PaveDrain System comes in standard Grey. However it is also available in Charcoal, Tan, Rose (Reddish) and Brown. Local manufacturing will determine which colors are ultimately available. Coloring does add cost to the square foot cost, typically around $1 per square foot. View available PaveDrain colors.
Does the PaveDrain System surface conform to ADA requirements?
Yes. ADA Design Guidelines require that surfaces be firm, stable, and slip resistant. Gaps between PaveDrain blocks do not exceed 1/2". Most gaps between PaveDrain blocks are 3/8".
What are the estimated LEED points that the PaveDrain System can qualify for?
Depending on the site the PaveDrain System can achieve several LEED points. It is up to the architect and engineer of record to determine which LEED points apply to their respective sites.
Do PaveDrain blocks have to be screened with a smaller stone similar to other interlocking paving systems?
Unlike traditional hand-placed pavers that require a small diameter aggregate between the joints, the PaveDrain System can be either screened or left open. We recommend leaving it open. The aggregate layer between the blocks can trap silts and sedimentation that can promote small vegetation growth and act as a clogging mechanism.
What is the psi load pressure that the PaveDrain System can withstand?
The PaveDrain System has been traversed with fully loaded flat-bed tractor trailers, utility trucks and vehicular traffic repeatedly for over 4 years. Recently, Pennoni and Associates, Inc. out of Bethlehem, Pennsylvania www.pennoni.com analyzed the blocks as unreinforced concrete arches under AASHTO Standards.