Frequently Asked Questions
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What is Grasspave2?
Grasspave2 is the world’s leading choice in porous paving – a flexible, recycled plastic structure that sits unseen below a real grass surface to allow for the weight of virtually any vehicle while protecting the grass roots. With ADA certification and a compaction strength of 15,940 psi, it has been a favorite for Fire Lanes, Emergency Access, and Parking Areas since 1982. Grasspave2 provides a long-term green paving alternative that can reduce CO2 emissions and filter out environmental toxins through bioremediation. See Grassspave2 for complete information.
How is Grasspave2 Installed?
Grasspave2 can be easily installed by a contractor or landscape professional. Roll out the product like carpet, over a compacted, porous base course and our specially formulated growth enhancer, Hydrogrow. Fill the rings with sand, finish with sod or seed and wait until roots are completely established (generally around 2 mowings) before use. For specific instructions on how to Install Grasspave2 please refer to our Installation Instructions.
What is the cost of Draincore2?
Use our Grasspave2 Estimator for a quote.
What depth base course does Grasspave2 require?
The depth of base course required is entirely dependent on the application. It is crucial that our Technical Specifications are referenced, and municipalities consulted for areas such as fire lanes, as these requirements vary. Overall, a general guideline would be an equivalent depth to the requirements for 2” of asphalt. See our Base Course Depth Recommendations chart for a reference – though all depths must be verified by an engineer and if applicable, the fire department.
What type of base course does Grasspave2 require?
The most important aspect of a base course for Grasspave2 and Gravelpave2 is its ability to maintain porosity while bearing weight. When choosing the right gravel to combine with sand for your road base, refer to our Technical Specifications for your project and avoid materials that solidify over time, losing porosity – like limestone. our base course should fit within the specifications of this Base Course Material Recommendation.
What is Hydrogrow and what purpose does it serve?
Hydrogrow is a specially formulated polymer designed to rapidly promote healthy root growth for at least one year with regular watering cycles. Included with every order of Grasspave2, it can be easily distributed over the base course using a Spreader.
Do pieces of Grasspave2 have to be connected when installed?
There are interlocking male and female connectors along the edges of each roll. If using Grasspave2 for a large installation, you can save time by skipping this step or interlocking only periodically, as the established grass roots will anchor the product. For fire lanes and any emergency access areas, it is recommended that all connections be made to maximize stabilization during the “off-limits” root growth period – in case of emergency.
What types of grass should I use for the product?
We recommend using a deep rooting and hardy species such as Blue, Rye, Fescue, Zoysia or Bermuda depending on your area. Both sod and seed will be successful, but if using sod we recommend one grown in sand or a sandy-loam, especially for emergency vehicular access in areas susceptible to heavy rains.
Does Grasspave2 work better with sod or seed?
Grasspave2 works very well with seed or sod. To achieve the best results with sod, use a thin cut sod or rinse off any excess soil with a hose prior to installation, as excess soil will cause compaction and loss of porosity. Hydrosourcing Seeding is most successful when a mulch is used. Avoid using mulch such as straw or pine as they generally do not retain enough moisture.
I’m concerned that Grasspave2 specifies using sand instead of soil – Will grass grow in sand?
Absolutely. Soil can compact and become impermeable creating mud, ruts and “bath-tubbing”. Because sand never compacts it remains porous allowing the roots to thrive, providing an excellent medium for growing any vegetation. The addition of our proprietary Hydrogrow (included with every order of Grasspve2) ensures water and nutrient retention at the base course level to expedite the root growth process after installation.
How heavy a load can Grasspave2 support?
Grasspave2 exceeds H20 loading and has a psi of 15,940 so it can support the weight of virtually any vehicle. This is one of the many reasons why Grasspave2 has been the leading choice for porous fire lanes, utility and emergency access roads worldwide.
How much traffic can Grasspave2 withstand?
While Grasspave2 is designed to withstand vehicular traffic, one must ensure that living grass gets enough sunlight, moisture and limited friction to protect its health. For example, parking in the same spots or frequent passes over the same areas on a daily basis will cause the grass distress. However, Grasspave2 continually protects the root zone so even if the grass blades are damaged by overuse they will recover.
Can Grasspave2 be used for fire lanes?
Yes, our second installation ever was one of the first porous fire lanes back in 1982, and since then we have provided product to countless other cities and countries worldwide. It continues to be our most popular installation.
Is Grasspave2 ADA compliant?
Absolutely. Grasspave2 and Gravelpave2 were the first, and continue to be one of the only ADA compliant porous pavers. For a link to our ASTM testing results for Grasspave2 click here.
Can Grasspave2 be plowed in the event of snow?
Of course. Grasspave2 is easy to plow year after year without needing to replace any sections because the product will flex and bend with the freeze-thaw cycle. Simply add a skid to the corners of the plow blades to raise them and proceed as usual.
Does grass planted with Grasspave2 require different maintenance than regular grass?
The only difference in how one cares for the grass covering Grasspave2 and regular lawn is aeration is not permitted, as aerating may cause damage to the Grasspave2 structure below.
How does the cost of Grasspave2 compare to the cost of concrete or asphalt?
Grasspave2 may initially be more expensive. However, because it requires minimal maintenance and will not need to be replaced due to cracking, the long-term cost will be far less. The lifespan for Grasspave2 is over 60 years.
What is the cost of Grasspave2?
Please see our Grasspave2 Estimator for product cost.
What is Gravelpave2?
Gravelpave2 is the first gravel porous paver and continues to be Designers’ top choice because of its impressive strength, ADA compliance, and long-lasting durability. Gravelpave2 is a 100% recycled plastic structure that can be easily installed beneath aggregate to stabilize and reinforce the surface. The unique ring-on-grid design, with fabric that will never come off keeps gravel in place, prevents weeds from growing through and acts as a dust inhibitor. With ADA certification and a compaction strength of 15,940 psi, Gravelpave2 has been used for countless numbers of fire lanes, access and utility roads, parking lots, driveways and pathways.
Does Gravelpave2 require a base course?
The requisite depth of a base course is entirely dependent on the application. Some applications, which do not require heavy load bearing capacity or flood zone type drainage, do not require a base course at all. Vehicular applications will require varying base depths depending on the weight in which it needs to support. Greater depths of base course also manage greater amounts of stormwater. It is crucial it is porous and that our Technical Specifications are followed.
What type of base course does Gravelpave2 require?
The most important aspect of a base course for both Grasspave2 and Gravelpave2 is its ability to maintain porosity while bearing weight. When choosing the right gravel to combine with sand for your road base, refer to our Base Course Material Recommendation and avoid materials that solidify over time, losing porosity.
Do rolls of Gravelpave2 have to be connected when installed?
Not necessarily. There are interlocking male and female connectors along the edges of each roll. The pieces can be easily snapped together in the field, but this step may be skipped on curves or large installations. However, the Gravelpave2 must be secured to the base course with the included 8” pins and washers. Need our Pinning Instructions?
What size and type of aggregate should I use as fill material for Gravelpave2?
The best choice for aggregate is small (3/16’), angular, hard stones that have been thoroughly washed. The angular stones will lock together in the ring creating a smooth, stable surface. The range of options is vast, and designers have used everything from recycled glass to crushed seashells. Softer materials that break down, such as limestone or decomposed granite, should be avoided as they will cause the surface to lose porosity. If opting for a round gravel, rings should not be overfilled as it will cause a slip-hazard.
Can I use a binder with Gravelpave2?
Absolutely. A binder will add to the maintenance of Gravelpave2 but only every few years. It can help with steep slopes, sections adjacent to water features or any areas you want to prevent stone migration. Whatever binder you select for your project, make sure it maintains porosity within the aggregate. For suggestions, check out this list.
How heavy of a load can Gravelpave2 support?
Gravelpave2 can support the weight of virtually any vehicle. With a compression strength of 15,940 psi, Gravelpave2 exceeds H20 loading and has been the leading choice for porous utility and emergency access roads worldwide.
How much traffic can Gravelpave2 withstand?
Gravelpave2 can withstand daily, high frequency traffic. There is no limit to the number of passes per day. However, Gravelpave2 works best in areas with low speed traffic.
Is Gravelpave2 an “All Weather” Product?
Yes. Rain or shine, sleet, snow, hail or ice – Gravelpave2 will withstand years of drastic temperature changes without cracking, breaking or causing an uneven surface.
Is Gravelpave2 ADA Compliant?
Yes. Gravelpave2 provides a smooth and stable outdoor surface and has been tested, certifying that it complies with the requisite ASTM F 1951 standard – (per the Department of Justice 2010 ADA Standards for Accessible Design – Section 1008.2.6 Ground Surfaces.) When using Gravelpave2 for an ADA application, we recommend the rings are not overfilled to provide the most stable surface possible.
What is the recommended maximum slope for Gravelpave2?
The recommended max slope for both Grasspave2 and Gravelpave2 is 5% for fire lanes, 8% for cars and lighter weight trucks, 15% – 20% for golf carts, pedestrian use and trails.
How does the cost of Gravelpave2 compare to the cost of concrete or asphalt?
Gravelpave2 may initially be more more expensive, depending on the requisite depth of a base course and desired type of gravel. However, because it requires minimal maintenance and will not need to be replaced or repaired in the long-term, the overall cost is less. The lifespan for Gravelpave2 is predicted to be over 60 years.
Can Gravelpave2 be plowed in the event of snow?
Of course. Gravelpave2 is easy to plow year after year without needing to replace any sections because the product will flex and bend with the freeze-thaw cycle. Simply add a skid to the corners of the plow blades to raise them and proceed as usual.
How is Gravelpave2 maintained?
Gravelpave2 requires very little maintenance. The gravel in high traffic areas may need to occasionally be brushed or swept back into place. Over time additional gravel may need to be added depending on ware and maintenance. Round gravel tends to migrate outside of the rings with more frequency than angular aggregate.
What is the cost of Gravelpave2?
Please see our Gravelpave2 Estimator for product cost.
What is Rainstore3?
Rainstore3 is a modular stackable underground water/liquid containment system. It is installed subsurface to be used as detention basins and retention harvesting systems. Made from 100% recycled plastic, units come preassembled for easy drop-in-installation.
What are the common Applications for Rainstore3?
Rainstore3 is a solution for stormwater retention and detention as well as other applications requiring liquid storage. Water will percolate through the ground or covering and can either run through Rainstrore3 at a controlled rate or be stored for later use. Common applications include:
- Underground Detention Basin
- Retention/Harvesting Systems
- Water/Rain Gardens
- Green Roofs
- Sports Field Drainage
- Downspout Catch Basins
- Utility Liquid Battery Storage
What is the Weight Capacity of Rainstore3?
Rainstore3 exceeds H-20 loading allowing it to support vehicular traffic, lightweight buildings or greenspace. Please see our H-20/Hs-20 Guide for more information.
How much water can Rainstore3 hold?
Rainstore3 is 94% void space. A single unit holds almost 25 gallons, which means each cubic meter is capable of holding up to 250 gallons.
What are the Main Advantages of Rainstore3?
Rainstore3, arrives pre-assembled, for easy installation. It is modular and stackable so can be installed in a wide range of depths, maximizing the capacity of water storage.
What is the Installation Process for Rainstore3?
Rainstore3 comes in preassembled custom height stacks that can be unloaded and dropped directly into the job site. Installation is fast and easy. For additional details please see the Rainstore3 Installation Guide.
How are the inlet /outlet pipes attached to Rainstore3?
Inlet and outlet pipes can be attached to Rainstore3 by forming a “boot” with the fabric or liner and securing it with a hose clamp.
How much cover is required over the Rainstore3 system?
A minimum of 12” of compacted road base and a geogrid layer is required above the Rainstore3 chambers.
What keeps the soil from entering the cells?
Rainstore3 is wrapped in a geotextile fabric or PVC liner so soil and vegetation are unable to penetrate the chamber.
Can Rainstore3 be inspected after it is installed?
Adding maintenance ports during installation allows Rainstore3 to be inspected after the installation is complete. Please see the Rainstore3 Maintenance Guide for Details.
Is Silt buildup an issue?
Silt buildup can be prevented by using proper pre-filtration, such as catch basins or sediment filters. Using Rainstore3 in conjunction with Grasspave2 or Gravelpave2 can eliminate the need for any filtration systems as the water would be filtered naturally through bioremediation.
What is the cost of Rainstore3?
Please see our Rainstore3 Estimator for product cost.
How much Rainwater can a Rainwater Collection System Collect?
The amount of rainwater which can be collected varies by the type and size of the collection system used. Rain barrels typically hold 50 – 55 gallons per barrel. A rainfall of ½” on a 1,000 sq. ft. roof will fill one barrel. Concrete and plastic storage tanks range in size from 250 gallons to 15,000 gallons.
Arch chambers, milkcrate and plastic modular systems are only limited by the length, width and depth of the area as well as the void space of the system. For example, arch chambers provide only 40 – 50% space for water whereas Rainstore3 provides 96%. Therefore, each 1 meter piece of Rainstore3 holds up to 25 gallons, even though it’s only 4” high. At the maximum depth of almost 8’, 24 units of stacked Rainstore3 can hold almost 600 gallons of water in a single stack.
How are Rainwater Collection Systems Used?
Rainwater Collection Systems are used for either water detention or water harvesting. Either method is an effective way to control stormwater for flood prevention. For reuse, water harvesting is required from an impervious vessel or storage basin. Harvested water can be used as gray water, for agricultural purposes or can be purified and used as potable water.
Water detention basins allow water to seep back into the ground recharging the ground water. The depletion of ground water has become one of the biggest environmental concerns our planet is facing.
All collection systems require some minimal maintenance in order to maintain optimal functionality.
What is an Underground Detention System?
Underground detention systems include any structure or vessel designed to store rainwater or other liquid beneath the surface of the ground. A primary function of the vessel is stormwater management. Rainwater can be captured and fed back into the Earth to replenish groundwater or collected and harvested for future use. Storing water underground provides additional security as well. Examples of underground detention systems include arched chambers and plastic modular systems such as Rainstore3.
Should I use a Rainwater Collection System?
There are several reasons to use a rainwater collection system. In areas with heavy rainfall where drainage is an issue, these systems can help mitigate the problems caused by flooding. All climates, including arid, can benefit by capturing rainfall and harvesting the water for reuse. Reusing water can save money and provide environmental benefits.
Another advantage of underground rainwater collection systems, not designed for harvesting, is that they can replenish the groundwater. Water shortages and the decrease in our ground water are among the planet’s biggest environmental concerns today.
What is Stormwater Management?
Stormwater management is anything designed to mitigate the adverse effects of stormwater such as flooding, mud, rutting, pooling and general lack of drainage. All Invisible Structures products are designed to address these issues.
What are Rainwater Collection Systems?
Rainwater Collection Systems include any vessel, tank or other basin that is designed to collect and store excess rainwater. Examples of these are barrels, concrete storage tanks, arched chambers, detention basins and plastic modular systems – such as Rainstore3. Reasons to collect excess stormwater vary from flood prevention to harvesting for the purpose of reuse. The efficacy of these systems differ based on size and design.
Rain barrels and concrete storage tanks are limited in their capacity because of their impervious walls, whereas arched chambers, detention basins, and plastic modular systems have unlimited capacity. Arched chambers and plastic modular systems have the advantage of storing water underground, allowing for usable space such as parking lots or green spaces on top.
Only Rainstore3 is strong enough to support the weight of structures such as a parking garage or small building.
What types of Rainwater Collection Systems are there?
There are several different types of Rainwater Collection systems. These include rain barrels, concrete storage tanks, arch chambers, milkcrate systems, and other plastic modular systems – such as Rainstore3. These different systems vary in size, cost, ease of installation and water storage/void capacity.
Rain barrels are the least expensive and do not require professional installation. Their capacity is limited by the size of the barrel. Concrete storage tanks are moderate in cost, also limited by their tank size, and require professional installation.
Arch chambers require a sizable installation area and a considerable amount of gravel fill which can be expensive. The void space is 40 – 50%. Milkcrate systems are mid-range in price but require complex assembly, which can add to the cost of labor. Their capacity is unlimited.
Modular plastic storage systems tend to be the highest initial cost but installation is relatively simple. Their capacity is also unlimited. Another benefit to plastic modular systems is the high void capacity and strength – Rainstore3 exceeds H-20 loading.
What is Slopetame3?
Slopetame3 is a permanent erosion control mat comprised of ISI’s trademark ring-on-grid system, crossbars on every row and a permeable vegetative fabric layer. Duckbill anchors are provided to secure every roll.
What is the difference between Slopetame2 and Slopetame3?
The new design has larger rings, making the whole roll lighter and easier to install. We also added cross-bars to every row (formerly every other) to further assist in the instant containment of erosion.
What is the difference between Slopetame3 and other erosion control solutions?
Slopetame3 is unique in that it is an immediate and permanent solution. The three-dimensional containment system is installed just an inch below ground and isn’t visible from the surface. The permanent fabric backing allows for both containment and root growth/penetration for vegetation.
How does the cost of Slopetame3 compare to other erosion control solutions?
Slopetame3 is initially more expensive than other erosion control mats but is a permanent solution that will not require maintenance or need to be replaced. Slopetame3 is generally less expensive than the installation of a gabion or retaining wall.
What is the required depth for Slopetame3?
Only a 1” depth is required for vegetation and/or gravel fill.
What is the maximum slope angle Slopetame3 can support?
Slopetame3 can permanently stabilize slopes up to 45 degrees or a 1:1 ratio.
Can Slopetame3 be used on a grass slope intended for pedestrian or vehicular use?
Slopetame3 can be used and will support the weight of pedestrian and most vehicular. However, grass on a slope can be extremely slippery and these installations should be done with care.
What is Beachrings2?
Beachrings2 is a temporary, reusable and easy-to-roll-out way to create an ADA compliant surface over sand, dirt, grass or snow. The 100% recycled plastic is lightweight, textured and flexible. Beachrings2 is available in 4 sizes and 3 colors.
Where are Beachrings2 typically used?
While the number one use of Beachrings2 is to provide wheelchair access on beaches, there are many other surfaces over which Beachrings2 can provide ADA accessibility. They have been used for weddings, outdoor event flooring and residential use to create an easy-to-navigate surface.
What are the main advantages of Beachrings2?
Beachrings2 offers a slip-resistant surface that is easy to roll out. It is also lightweight and portable.
What sizes are available in Beachrings2?
Each Square unit is 40 cm x 40 cm (15.75 inches by 15.75 inches). Beachrings2 are available in 4 sizes. Beachrings2 must be at least 3 squares in width to accommodate wheelchairs and meet ADA compliance. See our Beachrings2 Size Details for more information.
What is Draincore2?
Draincore2 is a 100% recycled plastic ring-on-grid system that allows for rapid, high volume drainage. A 92% void space allows drainage at the rate of 42 gallons per minute (per square foot.)
What are the main advantages of Draincore2?
Draincore2 is made from flexible 100% recycled plastic that can be slightly bent and shaped without connectors, T-joints or clamps. The product arrives in rolls and is lightweight and easy to install. The 92% void space allows drainage at the rate of 42 gallons per minute (per square foot) on sports fields, golf courses and planters.
What are common applications of Draincore2?
Common applications of Draincore2 include outdoor sports fields, golf courses, green roofs, retaining walls and planters.
What is the recommended maximum slope for Grasspave2?
The recommended max slope for both Grasspave2 and Gravelpave2 is 5% for fire lanes, 8% for cars and lighter weight trucks and 15% – 20% for golf carts, pedestrian use and trails. For grass installations with a slope greater than 20% Slopetame3 may be used and will support pedestrian and most vehicular traffic.