Admixture and Paver Surface Treatment Supplier to Manufactured Concrete Products Producers

Integral Water Repellent System for Architectural Concrete Masonry

The RainBloc® System

RainBloc CMU and mortar admixtures are designed to impart water repellent properties to CMU and masonry mortar. The RainBloc System has decades of successful water repellent structures in place to testify to its effectiveness and longevity.

When to Use it

The RainBloc System works in any architectural CMU application, and is particularly effective in lightweight CMU and single-wythe masonry walls.

Peace of Mind for Specifiers

Concrete masonry produced with the RainBloc Integral Water Repellent System resists wind-driven rain while still maintaining vapor transmission, reducing the chance of mold, mildew, and musty smells from developing inside a building.

How it Works

RainBloc water repellent admixture is added to the concrete masonry units (CMU) mix by a certified producer during manufacture.
RainBloc for Mortar water repellent additive is mixed with masonry mortar at the construction site.
Masonry walls with the RainBloc System are protected from moisture ingress, including from wind driven rain which is a common cause of moisture ingress problems.
The RainBloc System has decades of successful water repellent CMU structures in place that document system performance and durability

RainBloc “Anti-Wicking” Feature

Untreated concrete masonry units readily absorb water through a process called capillary suction or “wicking action”.
The RainBloc anti-wicking feature ensures that masonry units and mortar strongly resist water absorption. If rainwater seeps past the exterior face of the wall, the RainBloc System’s water repellent properties minimize the amount of water that can be absorbed into the concrete, causing any water inside the wall to flow to properly installed wall flashing and weep holes.

Other RainBloc System Features

The RainBloc System improves moisture penetration resistance:
+ High performance, polymeric based material
+ Durable for the life of the masonry structure
+ Covers CMU and mortar
+ Provides a full-wall thickness water penetration protection system 
The RainBloc System improves moisture penetration resistance.
As an added benefit, RainBloc also reduces the potential for efflorescence.
Concrete Masonry Structure Exposed to Wind-Driven Rain

Untreated Concrete Masonry Units

  • Moisture can penetrate through the untreated concrete surface
  • Untreated concrete matrix has excess voids that moisture can penetrate into
  • Wicking action pulls moisture through excess voids and capillaries deeper into the concrete

RainBloc Treated Concrete Masonry Units

  • Water repellent blocks moisture from entering at the surface
  • High quality concrete matrix reduces voids that moisture can penetrate into
  • Anti-wicking action reduces water movement in voids and capillaries
RainBloc Performance in ASTM Standards and Tests
RainBloc test data earns excellent ratings
ASTM E 514-74, “Standard Test Method for Water Permeance of Masonry.” This aggressive standard exposes
test walls to simulated, wind-driven rain for 72 hours, exposing them to the equivalent of 5 inches of rain per
hour pushed toward the wall with a pressure equivalent to a 62 mile per hour wind. A grading system to ranks
wall performance, from “L” for “leakage” to “E” for “excellent”.
RainBloc earns an “E” for excellent on ASTM E514 tests
Untreated Concrete Masonry Test Wall 
After 72 Hours
RainBloc Concrete Masonry Test Wall
After 72 Hours

RainBloc System Design and Application

A complete water repellent system emphasizes proper masonry design, details, and implementation. Although the RainBloc Integral Water Repellent System provides excellent rainwater penetration resistance, it should not replace proper flashing, weep holes, and control joints in masonry construction. The designer must provide the mason contractor with detailed illustrations of adequate flashing, weep holes, and control joints.

RainBloc Certified Producers

To qualify as a RainBloc Certified Producer, CMU from that producer must pass a series of performance and water repellency tests for specific water repellent mix designs. Performance testing  and verification allows specifiers to specify RainBloc admixtures with confidence.

Performance Report

Each certified RainBloc producer receives a performance report that includes:
+ RainBloc Spray Bar Test Method Results
+ Masonry Unit Physical Properties
+ Certificate of Performance
RainBloc for Mortar
Liquid Water Repellent Additive for Mortar
Increase mortar resistance to ingress and wind-driven rain
Add at the construction site, side panel has volume indicators for easy and accurate measuring
Meets or exceeds performance requirements for high quality mortar in ASTM E514 and ASTM C1384
Does not adversely affect mortar bond
ACM Chemistries employs the most knowledgeable and competent technical sales and support staff in the industry today. Our knowledge of machine-made concrete products, including the material science and technology used to manufacture those products, helps us optimize quality and performance, while reducing manufacturing costs for our customers. We make sure that our staff retains expertise in concrete and masonry technology and best practices for providing technical services to our customers and the industry.