[Product Focus] GCP Waterproofing HRA Membrane

You can’t understate the importance of a sound building envelope.

Since launching the Perm-A-Barrier line in 1985, GCP Applied Technologies has had plenty of time to R&D stronger and more reliable commercial waterproofing solutions. The decades of evolution have yielded another new innovation – Perm-A-Barrier HRA.

In this edition of our Product Focus series, you’ll get all the key stats and facts about this new addition to the Garvin distribution catalog. We’ll give you an exclusive, objective look at when Perm-A-Barrier HRA is ideal for waterproofing a building envelope, and when it’s not.

(Part 1 of Series: DOWSIL Paintable Sealant)

By the Numbers: GCP Perm-A-Barrier HRA Waterproofing Membrane

• Product: Perm-A-Barrier
• Type: Waterproofing membrane
• Manufacturer: GCP (fka Grace Construction Products)
• Material: HRA (hot rubberized asphalt)
• In a Nutshell: A single-component, hot liquid-applied system for monolithic waterproofing of horizontal decks

Perm-A-Barrier HRA is a bituminous waterproof membrane composed of premium asphalt, synthetic rubbers, and stabilizing fillers. This blend of materials produces a compound that fully adheres to its substrate and is highly resilient.

*Initial curing starts within a few hours. 

Perm-A-Barrier is less of a product and more of a product ecosystem. The full Perm-A-Barrier portfolio of GCP/Grace waterproofing products includes not just HRA membranes, but also several accessories. Together, the system restricts water migration, safeguarding buildings from the worst of Northeast and coastal weather.

Benefits of GCP’s Latest Waterproofing Wonder

As with past GCP liquid membranes, the Perm-A-Barrier HRA seems built to balance strength with flexibility. Benefits of this new offering include:

1. Long-Lasting

What’s better than a seamless, fluid-based waterproofing product? One that holds up to just about anything.

Perm-A-Barrier HRA is a 215-mil, polyester-reinforced system. with rare reliability and longevity. These membranes can withstand harsh environmental conditions, including:

• Temperature swings
• Water
• Chemicals

Remember that the lifespan of a fluid-applied membrane can vary based on installation quality (more on that below), environmental conditions, and attention to maintenance.

2. Great Adhesion

Hot fluid-applied waterproofing is excellent at adhering to construction surfaces, mainly because applying it requires it to be in a molten state. The mixture seeps into the substrate ever so slightly, creating an interlocked bond as it solidifies. This bond is superior to cold fluid-applied membranes in similar conditions.

Using HRA correctly results in a thick, sturdy, uninterrupted layer across the surface.

3. Versatile

Like most GCP products, Perm-A-Barrier HRA is compatible with a variety of substrates. You can confirm compatibility with an ASTM adhesion test.

The flexibility of GCP’s hot rubberized asphalt is ideal for sealing commercial components, such as:

• Pavers
• Concrete slabs
• Green overburden 
• Over any occupied space

To even better accommodate your construction process, the material is cold weather-friendly. It’s possible to use it in temperatures as low as  0°F, as long as the surface is dry and there’s nothing frozen to it.

4. Compatible

“Bang for your buck” is important for both the property owner and the contractor. 

That’s why it’s a relief to see that Perm-A-Barrier HRA doesn’t leave past products in the dust. It integrates seamlessly with building envelope products such as:

• Perm-A-Barrier air & vapor barriers
• Preprufe waterproofing membranes
• Bituthene waterproofing membranes

Together, you should be able to waterproof any commercial building with confidence.

When to Use (& Not Use) Perm-A-Barrier HRA

Bridges, terraces, and roofs are structures that demand a high-adhesion waterproofing membrane and can benefit from Perm-A-Barrier HRA. The manufacturer is promoting the material as a balanced solution for:

• Horizontal plaza decks
• Green (vegetated) roofs
• Planters
• Other areas that need monolithic waterproofing

Avoid This Product When …

No hot liquid-applied waterproofing product is ever going to be perfect. You may want to avoid Perm-A-Barrier HRA in certain cases:

• Highly populated or poorly ventilated areas: Odor concerns may bother occupants
• Inaccessible areas: You need to be able to lug heavy equipment to the site and heat it.
• Lightweight insulating concrete: The substrate won’t offer enough stability or adhesion for the application to work.
• Price is the only factor: If the property owner’s mindset is “low cost at all costs,” you’re pretty much stuck using a basic (single-component), cold fluid-applied product.

An approved GCP distributor with technical product knowledge can help you decide on a product and how to best install it. See the Perm-A-Barrier HRA data sheet for more in-depth details on installation. 

Other Commercial Waterproofing Options

It’s early, but our verdict so far is that GCP’s latest waterproofing solution meets or exceeds its long tradition of construction-grade reliability. The recurring theme is “use”: Perm-A-Barrier HRA’s useful life, versatility in usage, and ability to be used alongside other products make it a contractor-friendly choice.

As always, check your specs and job site conditions before picking a construction material or sealant. From there, verify the product’s compatibility – and availability – with your distributor.

Of course, there are other great commercial waterproofing products in the GCP lineup and at other manufacturers. To see a full list of suppliers with our seal of approval, click below: