Amerimix Introduces Water Repellent Mortar with RainBloc GP

Words: Bronzella Cleveland

Amerimix®, a manufacturer of preblended mortar, grout and stucco mixes, has unveiled its new water repellent masonry mortar: Amerimix Water Repellent Mortar (WRM) with RainBloc GP®.

With proven performance both in independent laboratory testing by The National Concrete Masonry Association (NCMA) and on the job site, Amerimix WRM with RainBloc GP inhibits water from penetrating a wall system. The mortar also is part of the total RainBloc system and, when used with concrete masonry units (CMU) that contain RainBloc, creates a wall system with superior moisture resistance, the company says.

The patented RainBloc GP technology in Amerimix WRM is the only water repellent agent that is traceable and measurable in the hardened mortar, verifying that the exact proportions for optimal water resistance are included in every bag and every batch. Amerimix WRM also performs as well as mortar without water repellent additives, offering the same superior bond strength and extended mortar board life with less re-tempering required.

And since RainBloc GP is factory blended into Amerimix WRM, masons can save time and money with no measuring, additional steps, waste or mixing mistakes at the job site — while also eliminating the need for stocking liquid admixtures. Third-party field testing by the NCMA also confirms that Amerimix WRM helps to make application easier with no impact on the feel, application or workability of the product.

Specifiers, too, can benefit from the mixture being factory blended under controlled conditions to guarantee that the precise amount of RainBloc GP repellent agent is consistently mixed in every batch for optimal performance, Amerimix reports. This helps to ensure that Amerimix WRM will work as specified — and that what you specified is what you get.

“Our Amerimix WRM formulation is an innovation that provides superior protection against moisture penetration and leakage, while also helping to make masons’ jobs easier with a pre-blended formula for no-hassle applications,” said Bob Ruby, technical product manager for Amerimix masonry products. “Also, because RainBloc GP is traceable and measurable after installation, it gives specifiers peace of mind that their project is executed as specified.”

Ideal for both interior and exterior applications, Amerimix WRM is specifically engineered to provide long water retention, exceptional workability, and superior bond strength over masonry substrates. Additionally, Amerimix products can help contribute to LEED® Materials and Resources credits for recycled and regional materials.

The STABILA Force Driven by Operations
July 2025

Leadership In today's competitive business landscape, maintaining an efficient, well-organized warehouse is essential for meeting customer demands and ensuring smooth operations. By implementing effective processes and best practices, businesses can achi

MASONRY STRONG Podcast, Episode 24 Recap: Gary Hensley, VP of Sales at Oldcastle Adams
July 2025

On this episode of the MASONRY STRONG Podcast, Gary Hensley joins Justin in Indianapolis to talk about his story within the masonry industry, how he got started, how he's seen it evolve, and where he sees it going. Why the Masonry Industry? Concrete and

The Enduring Power of Structural Masonry
July 2025

Masonry has been holding its ground for millennia — literally. And thanks to the simple brilliance of arching action, it continues to do so with strength, style, and surprising efficiency. In an era of advanced modeling and fast-moving schedules, one time

Marvelous Masonry: Belém Tower
July 2025

The Belém Tower in Lisbon, Portugal, stands as a testament to stone construction's enduring artistry and technical prowess. Erected between 1514 and 1519, this iconic structure served as a defensive bastion at the mouth of the Tagus River and as a ceremon