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Fernco Infrastructure · Strong-Seal®
Cementitious Products
Rehab, not replacement.
Strong-Seal® mortars, liners and grouts stop leaks, rebuild lost material and line manholes, culverts and other structures from the inside. No excavation, no trench to restore, and hold times measured in hours after the final pass.
What’s at stake
Aging sewers cost everyone
D+
Grade for U.S. wastewater infrastructure
ASCE 2025 Report Card
23K–75K
Sanitary sewer overflows a year in the U.S., by EPA estimate
U.S. EPA Report to Congress, 2004
3×
Inflow from a major storm can more than triple the volume in a sanitary sewer
Metropolitan Council (Twin Cities, MN)
$69B
Yearly gap between wastewater and stormwater capital needs and funding (2024)
ASCE 2025 Report Card
Why manholes matter
A leaking manhole is a hole in the budget
Manholes sit in the street, take traffic loads and see some of the worst sewer gases. When they crack, corrode or lose mortar, clean groundwater and stormwater pour into a system built for sewage.
01
Clean water gets treated like sewage
Groundwater that leaks into a sanitary sewer mixes with the sewage, and the plant has to treat all of it. That’s capacity and cost a community pays for with nothing to show.
02
Storms overload the system
Inflow and infiltration can push a sewer past capacity in heavy rain. That’s when untreated wastewater backs up or overflows into streets, basements and streams.
03
Corrosion keeps going
Bacteria turn hydrogen sulfide gas into sulfuric acid that eats concrete and mortar. Left alone, a manhole loses strength until it has to be dug up and replaced.
Why rehab from the inside
Fix more structures with the same budget
Strong-Seal® products go in through the manhole opening. There’s no excavation, so the money goes into the repair, not into digging up and rebuilding the street around it.
Hull, Massachusetts
For communities
- Less digging, less disruption
Work is done through the manhole opening, so streets, driveways and businesses can usually stay open. - Matched to the corrosion you see
Liners are rated from pH 3 down to pH 1, so a structure gets the protection it needs without paying for more. - Budgets go further
Lining a structure in place avoids the cost of excavation and restoration, so the same budget can cover more manholes. - Works on concrete and masonry
Strong-Seal® liners are made for concrete, brick and block structures.
For crews
- Products that work together
Leak stop, patching, lining and grouting products designed to be used together. - Fast return to service
After QSR patching, storm runoff can return in 2 to 4 hours. Lined structures take 4 to 6 hours for storm runoff, longer for force mains and stream flow. - Hand or spray
Strong-Plug® and QSR mix in a pail. Liners spray with SprayMate® and MiniMate II equipment. - Published specs
Every sell sheet lists strength and other results tested to ASTM methods, plus mixing, curing and application steps.
The Strong-Seal® line
Find the right product
Grouped by the job. A typical manhole rehab goes in three steps.
1
Stop the leaks
First, stop the water.
Leak stop cement
Strong-Plug®
Hardens on contact with water and sets in under a minute. Apply as a slurry or dry powder.
<1 min final set
2
Patch and rebuild
Repair benches, inverts and voids, or rebuild heavy section loss.
Fast repair mortar
QSR
Hand-applied mortar for benches, inverts and voids. Final set in 15 to 30 minutes.
2–4 hr to storm runoff
Structure rebuild
Profile Plus
Spray-applied to rebuild heavily damaged structures to original dimensions, ready for a polymer topcoat.
48 hr to topcoat
Heavy or flowing leaks?
Stop running water with SealGuard® polyurethane grouts, then patch with Strong-Seal®.
3
Line the manhole
Spray-applied liners, picked by how much hydrogen sulfide corrosion you see.
No corrosion
MS-2®A
The economical portland cement liner, where there’s no sign of hydrogen sulfide corrosion.
pH 3 and higher
Mild to moderate corrosion
MS-2®C
Calcium aluminate liner that stands up to mild to moderate hydrogen sulfide corrosion.
pH 2 and higher
Severe corrosion
High Performance Mix
Made with 100% pure fused calcium aluminate cement, for severe hydrogen sulfide corrosion.
pH 1 and higher
Pipes and culverts
Line large-diameter pipe and storm culverts from the inside, and rebuild washed-out inverts.
Structural lining
Geopolymer
Fiber-reinforced geopolymer for large sewer and storm pipes and culverts, plus manholes and catch basins.
Sprayed or spun cast
Culvert lining
Storm Seal®
Spray-applied lining for corrugated metal, concrete and masonry culverts and storm drains.
24″+ culverts
Invert restoration
Grout 12,000
Self-consolidating grout that rebuilds culvert inverts before Storm Seal®.
12,000+ psi at 28 days
Fill voids and abandoned lines
Pump behind structures to stop leaks and settling, or fill pipes taken out of service.
Lightweight fill
Grout 250
Lightweight grout with the most yield per bag, for voids and abandoned lines.
1.91 ft³ per bag
Higher-strength fill
Grout 1,000
Portland cement grout for voids and abandoned lines where you need more strength.
1,000+ psi at 28 days
Engineers and spec writers
Writing a spec?
Sell sheets cover surface prep, mixing, application and curing. Tell us the structure and conditions, and our infrastructure team can help you choose products.
On the job
Strong-Plug® and QSR, by hand
Leak stop and patching from inside the manhole, no spray rig needed.
Press it into the leak
Strong-Plug® hardens on contact with water. Press it into the leak by hand.
Hold until it sets
Hold it against the active leak. Final set comes in under a minute.
Pack cracks and joints
Pack Strong-Plug into cracks and open joints in the manhole wall.
Trowel the repair
Trowel QSR repair mortar onto benches, inverts and damaged walls.
Mix in a pail
QSR mixes in a pail, so small repairs need no spray equipment.
Finish by hand
Apply QSR inside the manhole. Final set in 15 to 30 minutes.
Case study · Hull, Massachusetts
Brackish groundwater, flat grades, a 45-year-old sewer
Hull is a coastal town with high brackish groundwater and minimal pipe grades, so hydrogen sulfide had sped up the deterioration of its sewer structures. As part of a sewer rehabilitation bid, Green Mountain Pipeline Services stopped infiltration with acrylamide grout, pressure washed the walls to a sound substrate, then sealed leaks and patched with Strong-Seal® QSR. Crews lined the structures with ½″ of Strong-Seal® High Performance Mix and finished with an epoxy coat. The same project lined 10,000 feet of 36-inch interceptor with CIPP and rehabilitated over 1,000 vertical feet of precast manholes. Afterward, flow data at the treatment plant showed groundwater infiltration significantly reduced.
Preparation
Lined
Complete
The Strong Company
Products, equipment and support from one source
Fernco Infrastructure partners with The Strong Company because we share a commitment to the nation’s infrastructure, the same core values, and a focus on quality products made in the USA.
The Strong Company was founded in 1959 and has developed Strong-Seal® products and application equipment for manhole rehabilitation since 1989. Its mixers and pumps are manufactured in Pine Bluff, Arkansas, to place the same materials it makes.
1959
The Strong Company founded
1989
Strong-Seal® manhole rehab begins
4M
Vertical feet of manhole rehab, per The Strong Company
Spin casting Storm Seal® inside a culvert
Built to place Strong-Seal®
SprayMate® 35C, SprayMate® 35D and MiniMate II mixers and pumps, manufactured in Pine Bluff, Arkansas.
Trailer rig
Flatbed rig
Portable mixer and pump
Meet Fernco Infrastructure
An overview of our manhole rehabilitation and trenchless pipe repair solutions.
Documents
The Fernco Infrastructure catalog and a sell sheet for every Strong-Seal® product, with full specifications and application steps.
For distributors
Interested in carrying Fernco Infrastructure?
Fernco Infrastructure covers manhole, structure and pipe rehab with three product lines. Add them to your line card to serve municipal and contractor customers.
Sources: ASCE, 2025 Report Card for America’s Infrastructure: Wastewater. U.S. EPA, Report to Congress on Impacts and Control of CSOs and SSOs (2004). Metropolitan Council (Twin Cities, MN), Inflow and Infiltration fact sheet.
Not sure where to start?
Tell us about the structure and the conditions. Our infrastructure team can help you pick products and write the spec. Reach out, or find your Fernco rep.