
Manhole rehabilitation
Strong-Seal · Fast repairQSR Fast-Acting Repair Mortar
A fast-setting, hand-applied mortar for manhole benches, inverts and voids. Patch it, and storm runoff can return in 2 to 4 hours.
Fix benches, inverts and voids fast
Mix it by hand, place it by hand. QSR is a calcium aluminate repair mortar with fiberglass reinforcement. Use it to rebuild worn benches and inverts and fill voids, on its own or before a Strong-Seal® liner.
Mix only what you can place in 15 minutes. Final set in 15 to 30 minutes.
Over 1,000 psi in 1 hour and 2,000 psi in 24 hours.
QSR-BAG 50 lb bag · QSR-PAIL 40 lb pailBonds to concrete and masonry at 28 days. 0% drying shrinkage.
Calcium aluminate cement, formulated for pH 2.0 and higher.
Three repairs, one bag
Each one goes on by hand or trowel, over a clean, damp surface.
Apply firmly by hand or trowel, up to 1″ per pass, starting from the bottom of the invert. ½″ minimum total.
Slope the bench from the walls to the invert or center, ½″ minimum at the center. Round the wall and bench joint to an even radius.
Pack it in firmly by hand or trowel until the void is filled completely.
Five steps to a repaired manhole
- BypassPlug or bypass incoming connections.
- CleanPressure wash to a sound surface, 3,000 psi minimum. Remove loose brick, mortar and concrete.
- Stop leaksStop active leaks with Strong-Plug®. Some leaks may need weep holes.
- Mix and placeUse 4 to 5 fluid ounces of water per pound, water first. Place on a damp surface with no running water.
- Finish and cureTrowel smooth, then wet brush. Keep it damp for 72 hours if humidity is under 70%, or use an ASTM C309 curing compound.
Back in service: storm runoff and surcharge after 2 to 4 hours. Force main impact after 4 to 6 hours.
Part of a full manhole rehab
QSR is the middle step. Stop the leaks first, patch with QSR, then line the structure with a Strong-Seal® liner.
Before QSR, stop the leaksStrong-Plug®Sets in under a minute and hardens on contact with water. Once it sets, you can line right over it.See Strong-Plug ›
After QSR, line the structureStrong-Seal linersSpray MS-2®A, MS-2®C or High Performance Mix over the repaired structure to stop infiltration and restore strength. Pick by how much corrosion you see.See the liners ›
Meet Fernco Infrastructure
An overview of our manhole rehabilitation and trenchless pipe repair solutions.
Specifications
| Part numbers | QSR-BAG (50 lb bag, 40 per pallet), QSR-PAIL (40 lb pail, 42 per pallet) |
| Compressive strength (ASTM C109) | Over 1,000 psi at 1 hour, 2,000 psi at 24 hours, 3,000 psi at 28 days |
| Bond strength (ASTM C882) | Over 2,000 psi at 28 days |
| Drying shrinkage (ASTM C596) | 0% at 28 days, 90% RH |
| Working time | 5 to 15 minutes |
| Final set | 15 to 30 minutes |
| Yield | 0.57 ft³, or 13.8 ft² at ½″ thick (bag); 0.46 ft³, or 11.0 ft² (pail) |
| Rated to | pH 2.0 and higher |
| Made with | Calcium aluminate cement, pozzolans, lightweight aggregate and alkaline-resistant fiberglass |
| Water | 4 to 5 fluid ounces per pound |
| Mixing | By hand, spoon, trowel or handheld drill in a clean pail or bowl |
| Typical structures | Benches, inverts and voids in manholes, tanks and containment, tunnels and pipelines, wastewater facilities |
Common questions
Can I line over QSR?
Yes. QSR is made to repair benches, inverts and voids before Strong-Seal® liners are applied.
How much can I mix at once?
Only what you can place within 15 minutes. Working time is 5 to 15 minutes.
How thick?
Up to 1″ per pass, with ½″ minimum total at the invert or bench center.
When can flow go back in?
Storm runoff and surcharge after 2 to 4 hours. Force main impact after 4 to 6 hours.
What weather can I apply it in?
Don’t apply below 40°F, on frozen surfaces, or if the surface could freeze within 24 hours. Keep the material under 90°F and the mix water under 80°F. Chill with ice if you need to.
How is it tested on the job?
Cast four 2″ cube samples each day, or for every pallet used, whichever comes first. Package, label and return them to the manufacturer for compressive strength testing per ASTM C109, following the owner’s or manufacturer’s directions.
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.
Documents
The Strong-Seal QSR sell sheet with full specifications and application steps, plus the Fernco Infrastructure, Plumbing and WaterWorks catalogs.

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