Geopolymer Lining for Large‑Diameter Storm/Culverts (36–240 in) — Geo

Spray | GeoKrete Hinterland installs SAPL (spray‑applied geopolymer) systems for large‑diameter culverts, storm drains, and pipes, using manufacturer‑specified materials including GeoSpray and GeoKrete.

Diameter range: 36–240 in+ (project/access dependent)
Structures: round/elliptical culverts, CMP/RCP storm drains, box/arch shapes, outfalls, and manholes
Specs/standards: Installed to owner specifications; aligns with ASTM F3706 where applicable
Coverage: Florida and the Southeast with rapid mobilization and 24/7 emergency response

Case callout: Manatee County — Hinterland rehabilitated a critical 66‑inch stormwater line using geopolymer lining, restoring structural capacity with minimal community disruption.

SAPL (spray‑applied geopolymer) / SIPP Geopolymer Spincast

Hinterland Group delivers SAPL (spray‑applied geopolymer) trenchless rehabilitation—also known as SIPP spincast—for large‑diameter pipes, culverts, and manholes across the Southeast. Commonly specified geopolymer systems include GeoKrete and GeoSpray. Updated November 2025: Hinterland installs manufacturer-specified SAPL systems—including GeoSpray and GeoKrete—for culverts, large-diameter pipe, and manholes. Where solicitations require approved/qualified or “licensed installer” status, we provide current manufacturer letters and training certifications; third-party validations (e.g., WRc) are held by the product manufacturers. Explore our trenchless portfolio on the Services page.

Approvals note: Many SAPL systems carry third‑party validations (e.g., WRc Approved in the UK). Refer to manufacturer resources for current approvals and listings: GeoKrete and GeoSpray.

Introduction

SAPL (Spray-Applied Pipe Lining): Terminology and Standards

Terminology: SAPL refers to spray-applied geopolymer linings and is often used interchangeably with SIPP on this page. Commonly specified geopolymer systems include GeoKrete and GeoSpray.
Size envelope: Suitable for large-diameter rehabilitation — typically handling diameters of 24–120+ inches depending on conditions and access.
Standards: Design and installation can be aligned with owner specifications and the SAPL geopolymer standard practices outlined in ASTM F3706, where applicable.

Geopolymer Spincast, also known as Spray-In-Place Pipe (SIPP) lining, is a trenchless technology for structural rehabilitation and restoration of pipes, culverts, and manholes. Hinterland Group is a leading provider of this solution for municipal, industrial, and commercial clients across the southeastern United States, covering Florida, Georgia, the Carolinas, and beyond (source). All technologies are performed in-house by Hinterland Group, allowing for quality control, cost effectiveness, and timely project completion.

What is Geopolymer Spincast (SIPP)?

Spincast geopolymer lining is a process where specialized geopolymer mortar is centrifugally applied—or "spun cast"—against the interior wall of deteriorated underground infrastructure. The process creates a new, structurally robust layer inside an existing host structure, restoring its integrity and extending its service life.

Applications: Suitable for circular and non-circular pipes, culverts, and vertical structures like manholes.
Materials: High-strength, corrosion-resistant geopolymer mortar that bonds tightly to a variety of substrates.
Install Method: Robotic or manually-controlled spincasting equipment applies a uniform layer of geopolymer material.

Key Features

Trenchless Rehabilitation: Minimal digging and surface disruption
Rapid Installation: Quick return to service compared to traditional dig-and-replace
Structural Renewal: Restores or improves original structural capability
Chemical Resistance: Excellent performance in sewer, stormwater, and industrial environments
Seamless, Monolithic Layer: Significantly reduces infiltration/exfiltration and eliminates leaks
Applicability: Effective on pipe diameters ranging from small to very large (>100” typical)

Use Cases

Sanitary Sewers: Renewal of gravity mains or force mains with internal corrosion/structural defects
Stormwater Culverts: Repairing steel, RCP, or corrugated metal culverts experiencing wall loss or joint separation
Manholes/Verticals: Rehabilitating leaky, corroded, or degraded concrete and brick manholes
Industrial Drainage: Protecting high-value industrial assets from corrosive effluents
DOT/Transportation: Culvert and drainage restoration under roadways with minimal traffic impact

Hinterland Group’s SIPP Services

In-House Geopolymer Spincast Capabilities

Hinterland Group performs all SIPP/geopolymer spincast work with its own trained teams and equipment. This ensures:

Direct quality assurance
Project scheduling flexibility
Cost control for clients (source)

Common Service Markets

Municipal utilities/agencies
Departments of Transportation
Property management (HOA/POA)
Industrial facility owners
Commercial asset managers
Airports, stadiums, and large campuses

(Markets We Serve)

Emergency Response Availability

Rapid mobilization regionwide
24/7 availability, 15-minute callback commitment
Fleet and crews pre-positioned in FL, NC, and throughout the Southeast

(Emergency Services)

Step-by-Step Overview: Geopolymer Spincast Process

Inspection: Advanced CCTV and robotic equipment evaluate the host structure condition (source).
Cleaning/Preparation: Removes sediments, debris, roots, and loose material for proper adhesion.
Application:
Spincast head (robotic or cable-pulled) rotates to evenly apply geopolymer mortar to interior walls.
Technicians monitor and control thickness, adjust for host pipe size/shape.
Curing: Geopolymer material sets quickly; structure can often be placed back in service in hours/days.
Final Inspection: Confirm full, defect-free coverage and restored diameter.

Benefits of Geopolymer Spincast with Hinterland Group

Minimal Surface Disruption: No need for excavation—excellent for urban or sensitive environments.
Structural Renewal: Engineering-approved repair for fully deteriorated structures; provides new load-carrying capacity.
Hydraulic Restoration: Smooth, continuous finish improves flow; can restore original diameter.
Corrosion Resistance: Provides long-term resistance in harsh chemical/sewer environments.
Cost-Efficiency: Often lower total cost than dig-and-replace, considering traffic, restoration, and downtime.
Project Speed: Most projects completed in days, not weeks.
Green Solution: Extends asset life with no landfill waste (About).

Typical Project Types

Structure Type	Common Problems Fixed	Suitability
Gravity sewer pipe	Cracks, leaks, corrosion, wall loss	Excellent
Storm drains/culverts	Invert loss, joint gaps, infiltration	Excellent
Manholes	H2S corrosion, leaks, brick/mortar loss	Excellent
Force mains	Limited (must be out of service)	Case-by-case

Major Sectors Served

Municipalities: Sewer, stormwater, and water pipeline systems
Industry: Process piping, retention basins, transportation facilities
Commercial: Shopping centers, airports, sports stadiums, high-traffic sites
Property Management: HOAs, POAs, residential communities (see details)

Comparison Table: SIPP vs. Other Rehabilitation Technologies

Technology	Excavation Needed	Structural Renewal	Diameter Range	Chemical Resistance	Typical Return-to-Service
SIPP/Geopolymer Spincast	No	Yes	18"–>100"+	Excellent	Hours–days
CIPP Lining	No	Yes	4"–108"**	Very Good	Hours–days
Pipe Bursting	Partial	Yes (new pipe)	2"–36"	Depends on material	Days–weeks
Sliplining	Yes (excavation at access pits)	Yes	8"–60"	Depends on material	Days–weeks

**CIPP technology by Hinterland Group available for up to 108” (source).

Safety and Quality Assurance

Hinterland maintains a full-time OSHA-certified safety manager
Strict adherence to safety monitoring and quality inspection pre- and post-installation
Record of superior safety and low EMR values (About Us)

Project Examples (Case Studies)

Charlotte County Stormwater Collection System Rehabilitation

Utilized trenchless solutions for restoring critical stormwater pipes (case)

PGA Waste Water Treatment Plant Bypass

Emergency response service using trenchless repair (case)

Frequently Asked Questions (FAQ)

What types of pipes can be rehabilitated with geopolymer spincast?

Circular, elliptical, and large box culverts; concrete, clay, brick, CMP, and RCP with moderate-severe deterioration

How thick is the applied geopolymer lining?

Thickness is engineered based on structural requirements; commonly 0.5–2.0 inches (consult project engineer)

Does SIPP work for both gravity and pressurized pipes?

Primarily gravity systems; pressurized pipes like force mains may be suitable if taken out of service and approved by engineering

Can flow be maintained during SIPP application?

For gravity systems, temporary bypass pumping may be set up as needed to maintain service during repair

How long does SIPP geopolymer take to cure?

Geopolymers typically cure within hours; full structural strength achieved within 24–48 hours (site-specific)

Is SIPP suitable for manholes?

Yes, SIPP/geopolymer spincast is ideal for manhole lining, sealing against infiltration and corrosion

What are the advantages for municipalities?

No need to excavate streets, minimal disruption for residents, cost savings, faster project turnaround, long-term durability, regulatory compliance (Municipalities)

What maintenance is required after SIPP?

Occasional inspection per asset management best practices; typical geopolymer liners are maintenance-free otherwise

Contact and Next Steps

- For proposals, technical questions, or emergency response, contact:

Florida HQ: 2051 West Blue Heron Blvd., Riviera Beach, FL 33404
Phone: (561) 640-3503 or info@hinterlandgroup.com
Request Contact Us

Why Choose Hinterland Group?

All SIPP/geopolymer spincast performed by in-house, certified crews
Decades of trenchless technology leadership throughout the Southeast
Safety-first culture; rapid regional mobilization
Experience with municipalities, industry, property managers, airports, DOTs, and commercial operators (About Us)
Full range of trenchless services: CIPP, SIPP, pipe bursting, sliplining, manhole coatings, and more (Services Overview)

References and Further Reading

Geopolymer spincast SIPP is a versatile, proven, and structurally robust solution for the rehabilitation of pipes, culverts, and manholes throughout the southeastern United States.

Geopolymer Spincast for Pipes, Culverts, Manholes