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.

The Important Issues with Masonry Barrier Systems
July 2026

A barrier is an element, device, or material that is intended to stop something from passing through. Road barriers stop traffic, for instance. Sun lotion with a high SPF rating will stop UV rays (for a limited time) from damaging the skin. In masonry, ba

Four Home Design Trends Driving Masonry Demand in 2026
July 2026

As design trends continue to evolve, one theme remains consistent throughout 2026: homeowners want spaces that feel intentional, comfortable and enduring. According to Westlake Royal Building Products’ TrendLine platform, today's most influential trends e

The Modern Masonry Saw: Safety, Efficiency, and Smarter Cutting
July 2026

Masonry is a craft built on precision, strength, and durability. At the heart of every successful masonry project is one essential tool: the masonry saw. As technology evolves, so does the role of the saw on the jobsite. Today’s contractors are not just l

Getting the Finish Right on Burnished CMU
July 2026

The wall is complete. The lines are crisp. The coursing is tight, and the burnished CMU delivers exactly the refined appearance the design team envisioned. After weeks of coordination and careful installation, the project is final