Duo Patch – SpecChem | The Duke Company


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Consider The Duke Company your partner that can assist you with all your construction needs. We offer expert advice from our highly rated customer service. Furthermore, we offer the best values and fast delivery. For exceptional customer service & the fastest delivery in Upstate New York, call us for a prompt rental quote. We are proud to carry SpecChem products including Duo Patch.




Or call the  Duke Company at:

585-292-9870  (Rochester NY)

607-347-4455  (Ithaca NY)

(585) 335-5970 (Dansville NY)


Duo Patch is a polymer-modified concrete repair mortar. DUO PATCH is a two-component, polymer modified concrete repair mortar with integral corrosion inhibitor for use in horizontal, form and pour and when mixed to a stiffer consistency, vertical and overhead applications. DUO PATCH offers superior durability in industrial warehouse, parking deck, and roadway applications subjected to heavy loads and abrasion.




Features and Benefits
  • Contains integral corrosion inhibitor
  • Suitable for repairs from featheredge to 2”
  • Interior/Exterior overlayment applications
  • Excellent durability and adhesion
  • Excellent freeze-thaw durability
  • Easy to trowel high slump consistency
  • Dries to natural concrete gray color



Surface Preparation: The concrete must be sound and free of all foreign material, including oil, grease, dust, laitance or other surface contaminants. For maximum durability, saw cut the perimeter of the repair 1/8” deeper than the depth of the repair, creating a notched, reinforced edge. Mechanically abrade the surface by an engineered approved method in accordance with ICRI 310.2 Guideline
to a minimum CSP 5. All concrete surfaces to be repaired must be in a saturated-surface-damp (SSD) condition with no standing water on the surface.

Priming/Scrub Coat: Thoroughly clean all exposed steel reinforcing of rust and coat with SpecPrep SB. Prepared concrete must be SSD and primed with a spray or brush coat of SpecPrep SB and the repair mortar applied wet on wet or up to the recommended open time (see SpecPrep SB technical data sheet). As an alternative, apply a scrub coat of the properly mixed repair mortar by scrubbing a thin layer into the predampened substrate with a stiff brush. Place the repair mortar immediately before the bond coat dries.

Mixing: Mix 7.0– 7.5 pints (depending on desired consistency) of DUO PATCH Admix per 50 pound bag of material. Mix with a low speed drill. Add recommended amount of DUO PATCH Admix into the container, followed by slowly adding the DUO PATCH powder. Mix 2-3
minutes. Mix only what can be applied within the setting period. Do not exceed 7 pints of DUO ADMIX for applications over 1/2”. DUO PATCH can be applied in applications from feather edge to 1” in a lift for light traffic applications.

Deep Applications: Extending DUOPATCH with 3/8” pea stone in large, deep applications over 3/4” will create a concrete topping very similar in thermal properties to the concrete itself.

Large repair applications over 1”, DUO PATCH should be extended with clean, SSD, 3/8” aggregate up to 60% by weight (30lbs) and mix an additional 2 minutes. This extension will add approx .18 cu-ft to the unit yield and should be placed within 15-20 minutes.

Placement: Trowel, screed, or pour DUO PATCH firmly into the prepared area, ensuring intimate contact with the bonding surface. Finish DUO PATCH level with the surrounding concrete and allow to take an initial set. After the initial set, when DUO PATCH is surface hard, finish by hand troweling.

Finishing/Curing: Finish the repair material to the desired texture to best match the surrounding concrete. Do not add additional water to the surface during finishing. Lightly spray SpecChem SpecFilm as a finishing aid on this and any other polymer modified mortars to assist in finishing. DUO PATCH is self-curing under most conditions. In severe drying conditions, use an ASTM C-309 compliant, water based SpecChem curing compound.

Download Helpful Information:


Duo Patch is packaged in:

  • 50 lb bag of Duo Patch + 1 gal. jug of DUO PATCH Admix
  • 60 lb pail unit containing 50 lb bag of DUO PATCH + 1 gal. jug of DUO PATCH Admix

The Duke Company can assist you with your construction needs. We offer expert advice from our highly rated customer service. Furthermore, we offer the best values and fast delivery.


Or call the  Duke Company at:

585-292-9870  (Rochester NY)

607-347-4455  (Ithaca NY)

(585) 335-5970 (Dansville NY)


The Duke Company ships nationwide and throughout New York, or contact us for convenient pick-up locations including:

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High Rises,
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high-rise construction, power plants,
Building Maintenance

By David Szydlowski