Amerimix Releases Water Repellent Mortar with RainBloc GP

Words: Bronzella Cleveland

Amerimix, a manufacturer of preblended mortar, grout and stucco mixes, has released 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 jobsite, Amerimix WRM with RainBloc GP inhibits water from penetrating a wall system. Amerimix WRM with RainBloc GP also is part of the total RainBloc system and, when used with concrete masonry units (CMUs) that contain RainBloc, creates a wall system with superior moisture resistance, the company reports.

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. According to the manufacturer, 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 jobsite, 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 for masons with no impact on the feel, application or workability of the product.

Amerimix WRM with patented RainBloc GP technology is designed for applications where a water-repellent mortar is required in combination with CMUs that contain RainBloc water repellent. 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.

Elevating Masonry: Old Habits, Familiar Tools, and the Real Reason Masonry Contractors Aren’t Making the Switch
May 2026

Ask a masonry contractor how they run their jobsite, and the answer probably sounds familiar: paper logs, a flurry of texts, maybe a shared email thread. It works until it doesn’t. And yet, even as purpose-built field management software has become more a

The Cornerstone of Craftsmanship: Nurturing Masonry Talent Through Competition
May 2026

In the evolving landscape of skilled trades, masonry stands as a testament to enduring craftsmanship and dedication. Yet, the question of how to cultivate and showcase this vital expertise remains paramount. While the bright lights of national competition

There’s the Typical Way to Brace a Wall. And Then There’s a Better Way.
May 2026

Wall bracing is one of the most important safety considerations on any masonry jobsite, yet it is often treated as a task that happens after the wall is built. Crews return, equipment is brought in, and time is set aside to secure walls that have already

Remembering Harry McGraw
May 2026

The masonry industry has lost one of its great teachers and craftsmen with the passing of Harry Edward McGraw, who died April 26, 2026, in Houston, Texas, at the age of 93.