Grasspave2 FAQ

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. 

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.

Please see our Grasspave2 Estimator for product cost.

Grasspave2 is for both commercial and residential projects, as well as many government applications.

Grasspave2 adds a significant advantage by providing filtration for water through a process called bioremediation. Water will collect toxins and debris and as that water passes through the Grasspave2 the microorganisms in the base course will clean out that water.

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.

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.

Grasspave2 can handle or exceed HS-25 loading, H-20 loading. It has a compressive strength of 15,940 pounds per square inch, which is almost 2.3 million pounds per square foot. So, even the heaviest of vehicles will be just fine on Grasspave2. This is one of the many reasons why Grasspave2 has been the leading choice for porous fire lanes, utility and emergency access roads worldwide.

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.

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.

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.

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.

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.

Grasspave2 performs tremendously well in cold climates. Because it's made out of HDPE plastic, and the grids are flexible... that allows it to go through freeze-thaw cycles without cracking, breaking or popping up like the individual tiles that are out there.

Of course. Grasspave2 is easy to plow or shovel year after year without needing to replace any sections because the product will flex and bend with the freeze-thaw cycle. We recommend lifting the snowplow blade about an inch over the top of the surface and using a skid, either on the sides or the full length of the plow to prevent it from tearing into the surface.

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.

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.

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.

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. The base course material specified online consists of three parts #57 stone, one part concrete sand. The reason we go with this specification is to maintain the structural integrity and the strength of the system while also providing the porosity to handle any storm. If you need help mixing this we have a sieve report available online that you can supply your local supplier who will help you provide premixed material.

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.

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.

It should never really need to be replaced. It has a limited lifetime warranty. Should damage occur during shipping Invisible Structures will replace that product. The only other time that replacement might need to occur is if there is damage due to improper installation. Should there be issues with the base course, if the wrong base course was used, you could run into damage. With Grasspave2 if you install it with top soil or aerate the product that could possibly damage the Grasspave2 structure.

The 2020 roll is 6.6 feet wide by 65.6 feet long and covers 430 square feet. It is 212 pounds per roll. The 1010 roll is 3.3 feet wide by 32.8 feet long, weighs 53 pounds, and covers 108 square feet.

The advantages to Grasspave2 being shipped in rolls are that they are super easy to install, easy to handle and cover 430 square feet in a matter of seconds. The flexibility of the large rolls also allow for undulations in the base course which will provide you with a smoother surface once they're installed.