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JAHN Cathedral Stone Repair Mortars

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Henry Frerk Sons is pleased to be distributor of JAHN Repair Mortars by Cathedral Stone Products. This

Jahn Repair Mortar

single-component, cementitious, mineral based mortar is designed for the restoration of limestone, sandstone, granite, bluestone, marble, concrete, terra cotta, and brick.  Unlike competitors’ products, JAHN has specifically formulated individual lines for each substrate. All Jahn repair mortars are vapor permeable and contain no latex or acrylic bonding agents or additives. See color options here

Product Highlights

  • Single-Component: Mixes with water only, improving quality control and consistency of application.
  • Compatible Formulations: Compatibility of physical properties ensures that the plaster and substrate react to the environment in the same way.
  • Contains No Latex or Acrylic Bonding Agents: It protects the substrate by allowing salts, water vapor, and liquid water to reach the surface, preventing failure due to salt expansion or freeze/thaw cycles.
  • Tenacious Adhesion: Strong bonding capabilities without relying on synthetic bonding agents.
  • Factory Controlled: No field chemistry resulting in product variation.
  • Custom Colored Upon Request: Closely matches existing masonry. Choose from Standard or Custom Colors. Henry Frerks Sons has an in-house restoration lab onsite that offers custom color matching and custom blended colors and we can supply your project out of our Chicago facility.
  • Certified Installers: Only installers with certification from Cathedral Stone Products can purchase Jahn Repair Mortars.

Product Range

  • M70 Brownstone
    M70 Sandstone
    M70 Limestone
    M90 Concrete
    M100 Terra Cotta
    M160 Bluestone
    M160 Granite
    M120 Marble


Chicago Color Collection

Jahn Repair Mortar

We have created the Chicago Color Collection, which contains 18 repair mortars selected just for Chicago. These colors match many of the most common stone, concrete and terra cotta materials found in Chicago and neighboring cities, and all colors are in stock at Henry Frerk Sons. (Call to confirm stock quantities.) This collection includes limestone, brownstone, concrete, terracotta, and marble repair mortars. We also offer in-house custom color matching and blending through our restoration laboratory.


Certification Requirements

Only Certified Installers may purchase Jahn Repair Mortar. We offer certification to enable contractors, architects, and other professionals to obtain the required product certification. Our classes are two-day sessions and are discounted to $450.00 per person. Check the current schedule for upcoming classes


JAHN Cathedral Stone Information Resources

Basic patching procedures (PDF) English | Spanish

Stock color chart <pending>

Chicago color chart <pending>






Limestone M70 M70 Datasheet Safety Datasheet M70 Specs
Brownstone M70 M70 Datasheet Safety Datasheet M70 Specs
Terracotta & Brick M100 M100 Datasheet Safety Datasheet M100 Specs
Granite M160 M160 Datasheet Safety Datasheet M160 Specs
Bluestone M160 M160 Datasheet Safety Datasheet M160 Specs
Marble M120 M120 Datasheet Safety Datasheet Specifications
Concrete and Precast M90 M90 Datasheet Safety Datasheet Specifications
Casting Mortar M150 M150 Datasheet Safety Datasheet Specifications
Anchor Setting Mortar M80 M80 Datasheet Safety Datasheet Specifications
Injection Mortar (M35) M35 Datasheet
Crack and Void Injection Grout (M40) M40 Datasheet Safety DataSheet