Amerimix Releases Water Repellent Mortar with RainBloc GP

Words: Dan Kamys

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 is also 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 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 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, unlike other water repellent additives that can increase work time.

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.

 
Stop Juggling: The Best Way to Master Your Masonry Job Sites
January 2026

You’re in the business of building structures that will stand for generations. Yet, too often, the process of managing the job site feels built on quicksand. Every construction project manager knows the feeling: the constant, fra

Brick Jointers: Purpose, Patterns, & Practical Applications
January 2026

After leads have been built and bricks have been laid, it’s crucial to tool the joints before the mortar sets. The tool of choice for this task is a brick jointer, but it can be tricky to decide which one to use. This guide will walk through the purpose o

Laying It Straight: Line-Holding Accessories for Masons Who Demand Precision
January 2026

When it comes to laying brick, block, or stone, nothing replaces a good line. A tight, true mason’s line is the backbone of straight courses and clean elevations, and the hardware holding that line is every bit as critical. Bon Tool’s lineup of Line & Lin

The Importance of Eye Protection in Masonry
January 2026

There are few stereotypes more iconic than the image of a construction worker wearing a hard hat and safety glasses. Protective glasses are among the most common items worn by workers in the masonry field, second only to the hard hat. According to OSHA, w