Manholes account for a substantial amount of infiltration to wastewater collection systems, and yet they are relatively cost-effective to remediate.
Industry manufacturers offer numerous products to help seal these structures, whether made of concrete, masonry, or other material. Many of these same products also work well to repair or prevent deterioration in lift stations, wet wells, catch basins, and other structures.
The products listed here represent a wide range of materials and methods of application. To get a fuller picture of the possibilities for cost-effectively sealing manholes, consult the manufacturers’ web sites.
Waterproof protection
Brushbond two-component acrylic polymer-modified cement-based coating waterproofs and fills holes, cracks, and imperfections, permanently sealing aged brick, block, cast-in-place, and precast manholes. It protects walls from positive and negative hydrostatic pressure. The coating comes in pre-measured units, applies easily with a smooth consistency, and bonds to porous and nonporous surfaces. PrimeLine Products Inc.: 407/772-8131; www.primelineproducts.com.
Injected sealer
Prime-Flex polyurethane chemical grouts are designed for manhole, sewer pipe, and lateral grouting. The low-viscosity liquid resins are usually injected under pressure into or near leaks. Once the resin contacts water, it forms an expansive closed-cell foam or a gel depending on the material formulation. The foam can be flexible and resilient (hydrophilic) or rigid, but the cell structure crushes when compressed (hydrophobic). Prime Resins Inc.: 800/321-7212: www.primeresins.com.
Watertight joints
Conseal CS-102 butyl rubber sealant self-seals joints in manholes, concrete vaults and pipes, box culverts, and other precast concrete structures. Providing permanently flexible, watertight joints, the material is workable in temperatures from 30 to 120 degrees, and has a service temperature range from -30 to 200 degrees F. A high chemical and mechanical bond occurs when the sealant is applied to clean, dry surfaces, and the joints will not shrink, harden, or oxidize with age. Priming is normally unnecessary. Concrete Sealants Inc: 800/332-7325; www.conseal.com.
Sealing chimneys
Internal Manhole Chimney Seal prevents excess inflow/infiltration in manholes and stops pavement settling around manhole covers and catch basins. The rubber seals conform to the physical requirements of ASTM C-923, with a minimum 3/16-inch thickness for durability and resistance to puncturing and tearing.
The standard 8-inch internal seal is double-pleated, and the 10-inch-wide internal seal is triple pleated. Extra-wide internal seals have four pleats to allow for a minimum 2-inch vertical and 1/2-inch horizontal movement before stretching the rubber. The rubber’s flexibility allows one size to fit a frame/chimney diameter range of more than 20 percent. The seals have a tensile strength of 1,500 psi and are highly chemical resistant. Cretex Specialty Products: 800/345-3764; www.cretexseals.com.
Hydrophilic polymer
AV-202 Multigrout is a polymer solution that reacts with water to form a strong polyurethane film, gel, or foam to prevent water infiltration into manholes, sub-grade structures, and pipes. The nonflammable product handles heavy or light flow conditions, and cures under water. Avanti International: 800/877-2570; www.avantigrout.com.
CIP for chimneys
The CIPMN Chimney Works system has a one-size-fits-all stretchable felt liner with sealed seams and polyurethane coating. Delivered in pre-measured kits, the 100-percent solids, silicate-based, VOC-free resin produces strong bonds with no shrinkage. The liner, vacuum impregnated and cured under pressure, can be installed with minimal equipment and no manhole entry. It resists damage from freezing and thawing, leaves a smooth interior, and accommodates odd shapes. LMK Enterprises Inc.: 815/433-1275; www.performanceliner.com.
Stopping leaks
Parson Hydro Grout is a nonhazardous, low-viscosity hydrophobic polyurethane grout. Mixed with predetermined amounts of Parson Grout Accelerator, it exhibits controlled reaction times from 30 seconds to 3 minutes. The grout cures to a chemically resistant closed-cell foam that stops medium- to high-volume active leaks through hairline cracks in manholes, pump stations, and other structures. Parson Environmental Products Inc.: 800/356-9023; www.parson environmental.com.
Flow containment
The RELINER Inside Drop Bowl is a compact, simple, cost-effective solution for containing the flow of inside drops in manholes. The low-profile bowl attaches with stainless steel expansion bolts and special fully adjustable stainless steel pipe clamping supports to the manhole wall. Its design enables full access and inspection from above without reducing access to areas below.
When used with the RELINER Modular Invert System, the bowl provides fluid containment integrity. Solids and liquids remain together, eliminating erosion of walls and benches, and reducing hydrogen sulfide emissions. Service is from the street. Applications include new service installations, micro-tunneled services, wet wells, and existing and failed outside drops. Several standard and custom sizes are available. RELINER/Duran Inc.: 800/508-6001; www.reliner.com.
One-component sealer
QM-1s Restore is a factory-blended, high-strength, cement-based polypropylene fiber reinforced and shrinkage-compensated mortar enhanced with a mono-crystalline quartz aggregate (Granusil). Designed to repair concrete and masonry structures, the product’s formulation allows for a monolithic, one-pass application up to three inches thick by low-pressure spraying. Recommended for vertical and overhead repairs to sewer manholes, pipe, tunnels, and other facilities, the one-component blend provides uniform results. It has high early and ultimate compressive flexural and bond strengths, resists sulfate attack, and has extremely low permeability. Quadex Inc. 888/831-1650; www.quadexonline.com.
Versatile sealer
XSeal is a single-component, closed-cell, hydrophobic polyurethane that is applied during new construction and rehabilitation for assembling chambers, manhole sections, and vaults. It also is used for attaching grade/adjusting rings and manhole frames to the concrete cone. The product can bond concrete, metals, and plastics, expanding to fill voids and seal all substrates. SealGuard Inc.: 866/625-4550; www.seal guardinc.com.
Epoxy sealant
Perma-Poxy is a rapid-curing, medium-viscosity modified epoxy resin that repairs manholes, sumps, wet wells, and other structures. A single pass by spray, brush, roller, or trowel creates a 40- to 250-mil thick film that cures reliably even at low temperatures and in moisture. A hard surface typically develops in four hours or less. The resin is highly chemical resistant to acids, caustics, gasoline, and other hydrocarbons. Perma-Liner Industries Inc.: 727/507-9749; www.perma-liner.com.
Rotary-applied sealer
SewerGard No. 210RS is a rotary spray-applied material that protects concrete, steel, and new or rehabilitated substrates from chemical attack and physical abuse. When cured, the material creates an impermeable, high-strength, corrosion-resistant lining for manholes, lift stations, and similar facilities that are subject to infiltration and attack from hydrogen sulfide and acid. Sauereisen Inc.: 412/963-0303; www.sauereisen.com.
Layered resins
The SpectraShield liner is a 100-percent solids, VOC-free system engineered to seal manholes, wet wells, and other structures using multiple layers of polymer resins to impart structural strength, stop groundwater intrusion, restore structural profiles, and bar environmental penetration. Cured-in-place installation causes minimal disruption. The manufacturer states that a 7-foot-deep manhole can be lined in less than one hour. SpectraShield Liner Systems: 904/268-4951; www.spectrashield.com.
Fast-curing spray
SprayWall is a durable, spray-applied, VOC-free polyurethane coating that provides structural enhancement and chemical resistance in underground structures and manholes. The product’s formula enables curing to begin in less than 30 seconds, and the structure can be returned to service moments later. The material has a 50-year design life, retaining 70 percent of its original flex modulus. Sprayroq Inc.: 205/957-0020; www.sprayroq.com.
Stops microbe activity
Strong-Seal High Performance Mix is a pure-fused calcium aluminate mortar that protects against microbiological-induced corrosion, but also stops infiltration and restores structural integrity. Tests document that the material protects cement wastewater structures by limiting bacterial activity and thus regulating biosulfuric acid production. The Strong Company Inc.: 800/982-8009; www.strongseal.com.
Hydrophobic grout
Two accelerants give Hydro Active Cut, a hydrophobic polyurethane, the ability to stop even high-volume leaks. In contact with water, the grout expands and quickly cures to form a tough, rigid, closed-cell polyurethane foam that is unaffected by corrosive environments. The material is approved by UL for NSF 61 (potable water). DeNeef Construction Chemicals: 800/732-0166; www.deneef.com.
