Hydro Guard protects split-face block from leaks without changing its appearance

THE CHALLENGE

Split-face cement blocks have an appealing textured surface, created by chiseling the block after its cast. This finishing process creates irregularities in the surface, with crevices and recesses. It also exposes the stone’s inner aggregate, which is more absorptive and porous than the outer layer of the block. This creates around 17% more surface than a flat block. Irregular edges in split-face block also makes it difficult to ensure complete mortar coverage during construction, which means there are potential weak points and gaps in the mortar joints that can allow water ingress.

THE SOLUTION

At R&R Scaffolding’s offices in New Jersey, failures in the mortar joints in the exterior façade were causing leaks on the interior of the building. An inch by inch search for failure points was not cost-efficient for the customer. Hydro Guard was chosen as a protectant specifically for the split-face block because it was easy to apply. Unlike other membranes and sealants, Hydro Guard dries clear, protects the stone & mortar surfaces, and keeps both 98% “breathable” and was ultimately chosen by R&R for its protective efficacy and ease of application.

IMPLEMENTATION

1. Surface Preparation: The façade was cleaned and allowed to fully dry prior to application.

2. Application: Hydro Guard was applied using an HVLP sprayer on the full façade to the point of rejection and allowed to fully dry.

8 MONTHS POST-APPLICATION RESULTS & evaluation

8-months post-application, Armus returned to the site together with engineers. Using a 10x loupe, engineers observed no changes to the characteristics of the Armus-treated limestone compared to the untreated sections. Light soiling can be seen on the Pure Guard-only treated section on the far left and not in the section of the façade treated with both Hydro Guard and Pure Guard.


Our results show that the water-repellent treatment of Hydro Guard when paired with the self-cleaning properties of Pure Guard is the best-performing combination for protecting and maintaining this limestone façade.