• HOW TOs
  • MorFlexxWindow Brick App 3-15It’s ugly. Your mortar cracks and your stucco streaks. Replacement and repeated repairs are still ugly, not to mention costly and time-consuming. Forget the concrete powder, mix bucket, and big trowel. Just squeeze in Mor-Flexx® to repair crumbly mortar, cracked stucco, or textured walls. It’s easy, it’s fast, and it works. Mor-Flexx® is textured to blend in seamlessly with mortar and stucco, yet is elastic like rubber, able to span cracks for permanent, years-long repairs. With Mor-Flexx®, no one will know you had an unsightly crack, including you.

    Download Application Instructions

    Technical Data

    Mor-flexx® adheres to and mimics a variety of textured surfaces, including:

    • Stucco
    • Brick
    • Wood
    • Cinderblock
    • Mortar
    • Concrete
    • Stone

    Don’t see your surface listed? Contact us for help.

    Do Not Use:

    • On concrete less than 6 months old (the concrete is not fully cured)
    • In areas of water submersion
    • Where frequent or prolonged puddling occurs
    • In areas of high foot or vehicle traffic (use Sashco’s Slab® instead)
    • In areas where hydrostatic resistance is required
    • Will not adhere to or is incompatible with Kynar®, polypropylene, waxes, polyethylene, Teflon®, and silicone


    Kynar® and Teflon® are registered trademarks of their respective owners.


    Where to Use Mor-Flexx Stucco, Brick and Stone Mortar Repair Caulk

    “October 2011: It’s a few months later now, and I’m thrilled. The texture and color are excellent (I used gray), and it’s both hard and flexible – very ‘tough’ is good description. I won’t really know if it’s as great as I think for another 5 years or more, but so far I like it better than any other concrete repair material I’ve tried. I’ve used a number of concrete patch products – some in tubes, the concrete-vinyl patch materials, etc, and they either (1) flex well, but don’t match the texture/color of concrete (most ‘traditional’ caulks), or (2) are not flexible enough and crack again with just a bit of movement (most concrete patches – both in tubes and mixable). This stuff is expensive, but if it holds up as well as I expect it will, it’s more than worth the extra cost.

    “Update Oct. 2013: Still 5 stars! It’s now more than two years since filling the large cracks and this stuff is holding up great – still looks just like concrete, adhering extremely well without a single area where edges have pulled loose, and clearly very tough. No cracking or any other signs of distress. This stuff is great. Highly recommended.” – JohnG, review

    “I had a company quote me $1500 to fix all the cracks in my morter from my house settling over the years. I found out about this product on-line and found it in a local hardware store for $8. It was a perfect match for my mortar and was easy to apply. My friends can’t even tell where the cracks were. Awesome product. I would highly recommend it.” – biggunn, review

    “This is one of those top 0.1% products for me. It has literally saved me from having to replace (i.e. add a second tile layer) my old fashion type Spanish roof (a roughly 90 year old home). I can only imagine how much money this will save me. Basically these roofs become leaky when the mortar on the crest cap develops cracks and lets water leak in wherever it finds a hole in the tar paper below. I applied MOR-FLEXX 3 years ago to seal the cracks on the crest cap and it stopped my leak. I went up again today to apply some more and examine the roof. The 3 year old application still looks totally solid in spite of being constantly exposed to intense California sunshine. There is no degradation due to UV that I can see. The product is easy to apply, has the same grainy type texture of mortar to match and blend in well, does not contain any nasty solvents, adheres to my tile and solidifies any crumbly area, and even has enough thickness to fill substantially sized holes. It is just an amazing product and I am their customer for life.” – B. Cunningham, review

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Benefits & Features

•  Professional-looking results every time: The textured formula is easy to apply – no mixing needed! – even for a novice. Blends in for a seamless, beautiful repair.
•  Keeps the weather where it belongs – outside: Moves when your home moves to create a permanently waterproof and weatherproof seal.
•  Helps you avoid repeated repairs: Just say no to crumbly mortar and cracked stucco. Stays soft and elastic over time for a years-long, lasting seal.
•  Paintable: Paint adheres like a pro, so you can get the color and the texture you want.
•  Easy to use: Easy to smooth and clean-up with water. No special chemicals required.
•  OK to leave in your unheated garage overnight: Freeze-thaw stable through 10 cycles.