Invisible Structures Rainstore3 User manual

Rainstore3Storm Drainage Detention & Exfiltration with Geotextile Fabric 1
Rainstore3Installation Instructions
For Stormwater Drainage Detention & Retention with Geotextile Fabric
(A separate install guide for stormwater harvesting for reuse, is available - call 800-233-
1510 or visit invisiblestructures.com)
1) Introduction
A. This document describes how to properly install the Rainstore3water storage
system with geotextile fabric for stormwater drainage detention and retention.
B. Detention allows for short-term storage and release of storm water through outlet
pipes. Nearby water treatment plants may have a limited capacity for handling
storm water and thus, stormwater needs to be temporarily detained on site.
C. Retention allows water to recharge the ground water through exfiltration. There
are no standard outlet pipes from the system except in some cases when overflow
pipes are called for.
D. Contractors: Only licensed contractors should install the Rainstore3system. The
contractor should have a good performance record with similar construction
projects. Homeowners should not install the Rainstore3units themselves.
E. Landscaping: Plant only grass, flowers, or shrubs with shallow root systems over
the installed product. Trees should be carefully planned and CANNOT be planted
directly above a complete Rainstore3system. The deep tree roots can damage the
water storage capacity of the system by tearing the geotextile fabric and clogging
Rainstore3cells with root growth. Trees can be planted around the system, or
planted in an island of a parking lot devoid of Rainstore3 cells. Recommended
distance from Rainstore3system is 10 meters with a root barrier on the edge next
to tree.
F. Warning: Do NOT drive motorized equipment on any portion of the Rainstore3
area until installation is 100% complete. Driving over any part of the partial
installation could damage the geogrid, fabric, or Rainstore3cells, thus
compromising the integrity of the entire installation. Walking on the Rainstore3
units is acceptable.
G. Warranty: Invisible Structures, Inc. is not responsible for careless installations
that do not follow the technical specifications. The ISI warranty only covers
Rainstore3material defects. Please see the separate warranty sheet in the
Rainstore3brochure, or call ISI at 800-233-1510.
2) Material Requirements
A. Rainstore3: The cells arrive preassembled to the desired height. They will arrive in
a box truck on pallets. When multiples cells are stacked on one pallet, white paper
will divide each stack. Do not assemble, re-stack, or disassemble units onsite as
this will void the product warranty. DO NOT cut Rainstore3units. Units must be
installed whole. Cutting is only permitted for maintenance port installation (see

Rainstore3Storm Drainage Detention & Exfiltration with Geotextile Fabric 2
our Rainstore3maintenance port design detail). DO NOT disassemble,
reassemble, or reconfigure the height (stacks) of Rainstore3. Stacks must be
assembled at Invisible Structures manufacturing facility.
B. Geogrid: Acceptable examples are Tensar TriX 160, Tenax MS 330, or Huesker
Fornit 30 or equivalent. Geogrid is available in 2 rolls sizes: 9.84 ft x 164 ft roll
that weighs 102 lbs, or 13.1 ft x 264 ft that weighs 138 lbs. This product is not
supplied by Invisible Structures.
C. Geotextile: Non-woven PP or PET of at least 8-ounce per square yard. The
geotextile fabric is available in rolls measuring 12.5 ft x 360 feet or 15 ft x 300
feet. Both roll sizes weigh 240 lbs. This product is not supplied by Invisible
Structures.
D. Silver or metallic tape: the corners of the completed installation should be
marked with metallic tape for future utility detection.
E. Pipe Boot: to properly secure inlet, outlet, and maintenance ports to the
Rainstore3system use a pipe boot. Please view section 5.10 B for installation
instructions.
3) Equipment Requirements
A. A powered lift to move stacked Rainstore3cells into the excavated area. A back
hoe can have a fork or hanging chain attachment for lowering Rainstore3units
into the excavated area.
B. A walk behind roller for backfill compaction. For installations with an area of
1,000 square feet or more, a light drivable roller such as the Bomag 125 D-4 that
weighs 3,125 kgs (6890 lbs) or a compacter of similar weight may be used for
compaction after the first six inches of fill material have been installed.
4) Shipping, Handling & Storage
4.1 Unloading:
A. Rainstore3cells arrive stacked to the desire height in a box truck on wooden
pallets. Two or more workers per stacked unit can unload the cells. The
Rainstore3can also be removed from the truck with a powered lift.
oPowered lift: Rainstore3can be unloaded by a bobcat machine with a fork
attachment or a larger bobcat with a scoop attachment. To unload the units
with a powered lift, slide a pallet of Rainstore3to the rear of the truck
using workers or a pallet jack. Position the cells onto the fork or scoop
attachment.
B. Depending upon the height of the cells, a powered lift may be required for
removal from the truck. This could be a bobcat, forklift, or back hoe.

Rainstore3Storm Drainage Detention & Exfiltration with Geotextile Fabric 3
C. If a cell stack has a few cylinders that have become partially dislodged in transit
or offloading, simply apply even pressure onto the top of the cell to re-connect the
units – each cylinder top rib should touch adjacent cylinder’s bottom rib. If there
are more than twelve (12) cylinders disconnected in a cell stack, replacement cells
are needed.
4.2 Sun exposure:
A. If the product is not to be installed for five or more days after delivery, the
Rainstore3 cells MUST be stored out of the sun. Rainstore3should be stored in a
shed or covered with a UV resistant tarp. Too much exposure to UV rays from the
sun will weaken the plastic of the Rainstore3 cells. Failure to comply with
appropriate storage requirements could result in breach of the product warranty.
4.3 Inclement weather:
A. Install Rainstore3 only if the outside air temperature is 55 degrees Fahrenheit or
above. The plastic becomes brittle below 40 degrees F.
B. Rainstore3should not be installed on muddy soil or in standing water. The
excavated area should be dry before installation.
5) Installation
Pavement or Landscaping
Backfill/Base course
Geogrid layer #3
Geotextile fabric
Geogrid layer #2
Rainstore3cells
Geotextile fabric
Geogrid layer #1
Sub grade/ excavated area
5.1 Excavation Preparation
A. Excavate the area to the desired depth for the Rainstore3 system, as shown on site
plans. Allow proper depth for the height of the Rainstore3cells and the cover
material.
B. The excavated area must be dry, smooth, level, and devoid of rocks, lumps or
debris. Before installing the Rainstore3, test the area with a 3 meter (10 feet)
straight edge or laser level. The surface of the excavated area should not differ in

Rainstore3Storm Drainage Detention & Exfiltration with Geotextile Fabric 4
elevation more than 6mm (0.25 inches). All irregularities must be corrected and
re-leveled.
C. Excavation must extend at least three feet beyond all sides of the Rainstore3
placement area to allow ample room for product installation and sidefill
compaction.
D. All inlet pipes and filtering systems should be installed to the edge of the
excavated area per manufacturer’s recommendation. Please see section 5.10, for
installation of connection pipes from these devices.
E. Typically, inlet pipes are located near or at the top of the Rainstore3 chambers and
outlet pipes (if necessary) are located along the bottom of the system. An
overflow pipe should be located at the top of the system.
5.2 Geogrid – First Layer:
A. Three separate layers of
geogrid are required for
the Rainstore3 system.
Geogrid arrives in rolls
and can be shipped on a
flatbed truck. Rolls are
available in two sizes:
9.84 ft x 164 ft roll that
weighs 102 lbs, or 13.1 ft
x 264 ft that weighs 138
lbs. This product is not
supplied by Invisible
Structures. Two or more workers should carry the geogrid roll into the excavated
area.
B. Spread the first layer of geogrid at the base of the excavated area. The geogrid
will quickly unroll across the excavation area. Seams of the geogrid should
overlap at least 12 inches. The first layer provides a stable and even surface for
Rainstore3 cell installation.
C. The geogrid layers may be temporarily anchored with rocks or adequate debris, to
prevent it from rolling up before other system components can be installed.

Rainstore3Storm Drainage Detention & Exfiltration with Geotextile Fabric 5
5.3 Geotextile Fabric:
Geogrid layer #3
Geotextile (encases Rainstore3)
Geogrid layer #2
Rainstore3 units
Geotextile (encases Rainstore3)
Geogrid layer #1
A. A layer of geotextile fabric is installed on top of the first layer of geogrid. The
geotextile encompasses all of the Rainstore3cells. The fabric is permeable,
allowing for slow exfiltration of water but preventing sediments from entering the
cells from the surrounding area. Detention systems may require an outlet pipe,
please refer to your site plans.
B. The geotextile arrives in two rolls that measure 12.5 ft x 360 feet or 15 ft x 300
feet. Both roll sizes weigh 240 lbs. Two or more workers can lift and quickly
install the geotextile by unrolling it over the geogrid material. Seams should
overlap 12 inches. Seams can be joined with duct tape or a similar material to
prevent shifting of the geotextile fabric.
C. Be sure to leave excess fabric on all sides of the excavated area. The excess fabric
will later be brought up and around to encompass the sides and top of the
Rainstore3cells. The geotextile can be temporarily anchored at the sides of the
excavated area with rocks, bricks, or boards during installation.
5.4 Marking Rainstore3Placement:
A. The Rainstore3installation area can be outlined on the geotextile using spray
paint, chalk line, or even rope. If using rope, make sure to remove all rope after
the Rainstore3cells are in place.
5.5 Position the Cells:
A. Depending upon the height of the Rainstore3
cells, two to four workers can carry the cells and
place them on the geotextile fabric.
B. Workers can also use a dolly to roll the stacked
Rainstore3 cells into place. Take care not to allow
the stacked unit to tip over to prevent stacked
cells from damage. Damaged units CANNOT

Rainstore3Storm Drainage Detention & Exfiltration with Geotextile Fabric 6
be installed and must be discarded. Call ISI for replacement pieces at 800-
233-1510. Rainstore3units CANNOT BE CUT to fit the hole. Each unit must be
installed whole. No Partial unit is allowed unless making room for a maintenance
port (see 5.6).
C. A powered lift can be used as a small crane to lower Rainstore3cells into place.
The powered lift should use wide strapping around the Rainstore3cells. The
strapping should be placed under the pallet the Rainstore3cells are on to avoid
damage to the bottom of the cells. To avoid product damage or replacement, make
sure the strapping isn’t too tight around the top, bottom, or sides of the stacked
cells.
D. There are two sets of banding surrounding the
Rainstore3cells and pallet. Only cut the metal
banding that attaches the cells to the pallet, BUT
NOT the banding that holds the cell stacks
together. Remove and discard the pallet from
under the Rainstore3 units. If white paper divides
the stacked cells, remove and discard that as well.
E. Final positioning of cells should be done by hand
by at least two workers. The cells are placed side
by side, with the grid side down on the
geotextile fabric layer. Align bumpers on each
side of all stacked cells to ensure square
placement.
5.6 Maintenance Ports:
A. Depending on the size of the maintenance port, one or four Rainstore3columns
can be removed to install a maintenance port. The Rainstore3units can ONLY be
cut for maintenance port installation – no other cutting is permitted. The
Rainstore3cells can be cut using a powered cutter, such as a chain saw or a
reciprocating saw. NOTE: Cut ONLY the GRID between the cylinders, NOT
the cylinders themselves. The location of the maintenance port should be clearly
marked with tape or paint before Rainstore3cells are cut.
5.7 Geogrid – Second Layer:
A. The second geogrid layer is applied directly over the installed Rainstore3 cells and
provides a walking surface for workers. This layer temporarily interlocks the cell
stacks and prevents the geotextile fabric from being penetrated.
B. The geogrid easily unrolls with two workers. The seams should overlap at least 12
inches.

Rainstore3Storm Drainage Detention & Exfiltration with Geotextile Fabric 7
5.8 Wrap Geotextile:
A. After the second layer of geogrid is installed, the anchored geotextile fabric
surrounding the Rainstore3installation can be wrapped around all sides and the
top of the Rainstore3chamber.
B. Remove anchor material from the geotextile fabric. Enclose the Rainstore3cells
by bringing the fabric around the sides to the top of the cells. Seams should be
sealed according to manufacturer recommendations.
5.9 Add Maintenance Ports/ Connect Inlet & Outlet Pipes:
A. Prefabricated boots are available to provide a water tight connection between the
Rainstore3 units and any maintenance ports, inlet or outlet pipes. This replaces
securing the geotextile fabric around a pipe using a hose clamp. The
prefabricated boots are available from any geotextile manufacturer.
B. Boot Pipe Installation (from Environment Protection, Inc.
www.geomembrane.com)
a. Prepare the sub grade around the area of the pipe. The sub grade must be
smooth, uniform, and free of any protrusions.
b. Clean the surface of the liner around the penetration where the boot will
be welded in place. Wipe away any dirt or dust particles. The surfaces of
the liner, boot, and the pipe must be completely clean and dry.
c. Slide the boot sleeve on the pipe, making sure the boot is aligned and all
surfaces are smooth. It may be necessary to trim the excess tapered
portion of the boot sleeve.
d. Weld the boot apron to the liner using adhesive. Apply the adhesive to the
liner and the boot apron. Let the adhesive setup for several seconds before
pressing the boot apron and the liner together using a roller. Make sure to
smooth out any bubbles or wrinkles.
e. Seal the boot sleeve to the pipe using the stainless steel hose clamp. The
clamp around the pipe will form a watertight seal to the pipe.
C. Maintenance ports/boots and pipes should be completely sealed to the
impermeable PVC liner per manufacturer’s requirements.
5.10 Side Backfill & Compaction:
A. The area around the installed Rainstore3 structure must be backfilled with self
containing structural aggregate. The fill material should be applied gradually. The
fill should be compacted in a maximum of 12-inch high lifts to 95% proctor
density. Backfill to the top of the geotextile wrapped Rainstore3 structure.
B. To ensure the backfill is properly compacted, have a Geotechnical Engineer test
the fill density on site.
5.11 Geogrid - Third Layer:

Rainstore3Storm Drainage Detention & Exfiltration with Geotextile Fabric 8
A. When the side backfill compaction is complete, the third layer of geogrid is ready
for installation. The final layer of geogrid must extend beyond all sides of the
Rainstore3 installation at least three feet. The third layer helps dissipate the load of
traffic. Have two workers unroll the geogrid. Make sure the seams overlap at least
12 inches.
5.12 Top Backfill:
A. Add the top layer of backfill material over the geogrid material. The backfill must
be compacted in six inch high lifts to 95% proctor density. Use a walk behind
roller for small installations.
B. For installations with an area of 1,000 square feet or more, a light drivable roller
such as the Bomag 125 D-4 that weighs 3,125 kgs (6890 lbs) or a compacter of
similar weight may be used for compaction after the first six inches of fill material
have been installed.
C. Fill material should measure 12 inches minimum and 36 inches maximum. To
ensure the backfill is properly compacted, have a Geotechnical Engineer test the
fill density on site.
5.13 Surface Material:
A. Once compaction is complete, cover material may be placed. Landscaping
materials such as grass, or shallow root shrubs may be planted. For parking lot
applications: Grasspave2, Gravelpave2, asphalt, concrete or other pavement may
be installed.
Rev 10/2011