When it comes to waterproofing, the conversation often gets technical—fast.
Hot-applied vs. cold-applied systems. Membrane chemistry. Application layers. Cure times.

But on the jobsite, the decision usually comes down to something much simpler:

What works best for your conditions, your crew, and your schedule?

Let’s break it down into a straightforward, no-overthinking-required guide.

First, the Basics (Quickly)

At a high level, both systems are designed to do the same thing:

Create a monolithic, fully adhered waterproof barrier that protects the structure from water intrusion.

• Hot-applied systems (like RamTough 250) are heated on-site and applied as a fluid membrane that cools into a seamless layer
• Cold-applied systems (like Black Pearl®) are applied at ambient temperature and cure chemically into a durable, bonded membrane

Both work. Both perform.
The difference is how they get there—and what that means for your project.

Choose HOT-Applied If…

1. You Need Proven, Long-Term Performance in Demanding Conditions

Hot rubberized asphalt systems have decades of real-world performance behind them. They’re engineered for durability, even under ponded water and extreme temperature swings.

Best for:

• Plaza decks
• Green roofs
• High-traffic assemblies
• Projects where long-term reliability is the top priority

2. Your Project Has Complex Geometry or Heavy Detailing

Because hot-applied systems are fluid and seamless, they naturally conform to irregular surfaces, penetrations, and transitions.

Fewer seams mean fewer potential failure points.

3. You Have Time (and Equipment) on Your Side

Hot-applied systems require:

• Kettles or melters
• More installation steps and reinforcement layers
• Longer prep timelines (often requiring fully cured concrete)

Bottom line:
If your schedule allows for it—and your crew is set up for it—you get a robust, time-tested system.

Choose COLD-Applied If…

1. Schedule is Tight (or Phasing Matters)

Cold-applied systems dramatically reduce installation time:

• Faster prep
• No heating required
• Faster return to service

Some systems can even be applied to younger concrete, helping accelerate project timelines.

2. Jobsite Logistics Are Challenging

No kettles. No flames. No hauling hot material to elevated decks.

Cold-applied systems:

• Use smaller, easier-to-handle materials
• Reduce equipment needs
• Minimize safety risks tied to high heat

Best for:

• Tight urban jobsites
• Occupied buildings
• Projects with strict safety or fire restrictions

3. You Need Flexibility and Toughness During Construction

Cold-applied membranes are often highly elastomeric and resistant to jobsite abuse:

• Better resistance to abrasion and impact
• Strong crack-bridging capabilities
• Handles building movement and temperature swings

Ideal when:

• Trades are overlapping
• The membrane may see temporary exposure or traffic

The Reality: It’s Not Either/Or

Both systems create seamless, monolithic waterproofing layers—and both can be the right answer depending on the project.

At Barrett, systems like:

• RamTough 250 → hot-applied, seamless, built for long-term durability
• Black Pearl® → cold-applied, flexible, ideal for faster-moving jobs

…are designed to solve different jobsite challenges—not compete with each other.

The Simplest Way to Decide

If you’re still unsure, use this:

Choose HOT-applied if:

• You want maximum long-term durability
• The project allows for more setup and install time
• You’re working on large, complex, or high-risk assemblies

Choose COLD-applied if:

• You need speed and efficiency
• The jobsite has logistical or safety constraints
• You want flexibility and faster return to service

Final Thought: Don’t Overthink It

Waterproofing failures don’t usually come from choosing hot vs. cold.

They come from:

• Mismatching the system to the jobsite
• Overcomplicating installation
• Ignoring schedule and sequencing realities

The best system is the one that fits how the project will actually be built.

If you’re evaluating a project and want help narrowing it down, The Barrett Company can help guide you to the right system for your application.

Vegetated roofs are more than a beautiful addition to a building—they’re living, breathing systems that contribute to sustainability, stormwater management, insulation, and even occupant well-being. But like any living landscape, they require ongoing maintenance to perform at their best.

In this guide, we break down what it takes to care for your green roof over the long haul—seasonal checklists, common maintenance tasks, and specific considerations when working with Barrett Greenroof-Roofscapes® systems.

Why Green Roof Maintenance Matters

A well-maintained vegetated roof:

• Extends the lifespan of the waterproofing membrane
• Protects against drainage blockages and overgrowth
• Prevents wind uplift and plant loss
• Maintains appearance and ecological function
• Ensures continued compliance with stormwater and energy codes

Barrett’s Greenroof-Roofscapes® systems are built for durability and performance, but even the best assemblies benefit from a thoughtful, proactive care plan.

General Maintenance Checklist

Whether your roof is intensive or extensive, this core checklist applies year-round:

Remove weeds and invasive species
Inspect and clear drains and scuppers
Check for signs of erosion or plant die-off
Replace or replant damaged vegetation
Remove debris and litter
Check irrigation systems (if applicable)
Inspect waterproofing access points and flashings

Seasonal Maintenance Reminders

Each season brings new needs. Here’s a breakdown of what to focus on throughout the year:

Spring

• Inspect for winter damage and replant bare patches
• Test irrigation system functionality
• Fertilize if recommended for plant types
• Check for freeze-thaw membrane issues

Summer

• Monitor for drought stress and adjust watering
• Control weeds before they spread
• Prune overgrowth
• Watch for insect or pest damage

Fall

• Remove fallen leaves and organic debris
• Conduct the final weeding before dormancy
• Inspect drainage pathways ahead of winter
• Prepare irrigation systems for shutoff or winterization

Winter

• Minimize foot traffic during freezing conditions
• Inspect for ice dams or heavy snow load
• Monitor plant dormancy for abnormalities
• Check membrane edges and flashings after storms

Barrett-Specific Maintenance Considerations

Barrett’s waterproofing and green roof systems are engineered for performance, but their longevity depends on keeping protective layers undisturbed and functional:

• RamTough 250® and other fluid-applied membranes should be visually inspected at any accessible edge transitions or penetrations annually.
• Ensure that root barriers remain intact and are not breached by aggressive species.
• For modular systems like Roofscapes®, inspect module alignment and check for edge separation or uplift.
• If a Barrett drainage layer is used, never allow silt, sediment, or debris to clog the geocomposite drainage core.

Barrett offers long-term system warranties when maintenance is performed in accordance with recommendations—keeping documentation of inspections and repairs is key for preserving coverage.

A Partner in Performance

From the initial design of your vegetated roof to its long-term care, The Barrett Company is committed to supporting the entire lifecycle of your system. Our assemblies are built for the rigors of the real world, but it’s the attention to detail in maintenance that helps them thrive for decades to come.

Need help evaluating or maintaining your green roof? Contact Barrett for system-specific guidance or to connect with certified installers and maintenance professionals.

When it comes to implementing green roofs into building design, the benefits can be EXTENSIVE (pun intended).

But with any sort of ecosystem, sustainability and performance is dependent upon the level of protection & care it is given.

Performing routine, preventative maintenance is essential for keeping your green roof healthy & ensuring those benefits continue.

When a green roof is complete, most of the waterproofing membrane is covered with engineered soil & vegetation, limiting any inspection of the membrane to the elements that are visible or easily accessible. All green roofs must be inspected at least twice a year, generally in early spring & late fall, separate and apart from vegetation maintenance.

Black Pearl® Cold Applied Rubberized Asphalt Waterproofing System requires less maintenance than most other types of membranes. Semi-annual, scheduled inspections are not only prudent, they are cost-effective and can save considerable expense in preserving the warranty protection and extending the life of the system well beyond the warranty period.

Green roof horticulture inspections will vary greatly from project to project depending upon the specific vegetation, depth of soil, weather conditions, irrigation, environmental conditions, and various other factors. Each project must be evaluated independently for the proper vegetation maintenance schedule. During the establishment period, a monthly inspection is generally sufficient for simple, basic, low-profile green roofs planted with sedum unless during drought periods. Drip irrigation systems will require less attention.

The following evaluation sequence is suggested for your maintenance personnel, professional maintenance services, or professional consultants for the membrane portion of the green roof.

Perimeters

Walk the perimeter of each deck and, to the extent possible, examine membrane base flashings, metal counter flashings, caulking sealants, termination bar and metal edging for mechanical damage. Even minor scrapes or punctures need to be properly repaired as soon as possible to prevent any progressive damage. Any loose metal must be re-attached properly, and all caulking must be maintained to prevent water entry around the flashing. If base flashings are bulging, check for water behind the flashing. Check masonry weeps. If water or masonry efflorescence (a whitish, chalky discoloration) is present on either side of the masonry, the source of the water entry must be determined and corrected as soon as possible.

Drains

Examine each drain and remove any debris that has collected around the drain. Ensure that drains are operative. On stone ballasted installations, keep larger stones around the drain strainer to help prevent clogging. Do not use any devices that will restrict water flow. Insure drain clamping ring is intact & tightly bolted to the sump.

Roof Surfaces

Roof surfaces should be always kept clean of debris. On stone ballasted surfaces, where the stone ballast has been displaced exposing the insulation or filter fabric, the stone and fabric must be put back into position. If stone ballast is consistently misplaced due to heavy traffic, such as near door openings or mechanical equipment, replace the stone ballast with concrete pavers.

This should also be done if building geometry and exposure results in localized stone “scrubbing” displacement from wind. Exposed filter fabric or insulation will deteriorate with direct exposure to ultraviolet rays. Inspect all concrete pavers and concrete wear slabs for signs of cracking, disintegration, or other types of breakage. If deterioration is occurring, determine the cause and institute corrective action as recommended by the manufacturer.

Penetrations

Inspect all roof top penetrations such as vent pipes, exhaust fans, skylights, AC units, etc., checking for flashing tightness to substrate, metal flashings, seams, caulking sealants, termination bars, clamping rings and other visible elements.

If a new penetration must be installed through the deck, or if there is an addition to the existing building, contact the Barrett Company for recommendations. Barrett requires that any modifications to the membrane be performed by a Barrett Approved Contractor with Barrett materials of like and kind. This is an absolute requirement if the membrane is covered by a Barrett warranty.

Repair Materials & Chemicals

All petroleum-based products and harsh chemicals should be kept off the system. Any cleaning material, solvent, animal fats, grease, some water chiller chemicals, oil, or material containing any petroleum by-product, may degrade the membrane or other components. Any time such a product comes into contact with the membrane or insulation, an inspection is required to ascertain if damage has occurred.

If the membrane comes into contact with any type of chemical, contact Barrett Company for advice, since some chemicals can degrade the membrane, insulation or fabric. Black Pearl® or Ram Mastic is recommended for emergency repairs. Do not use random petroleum-based roof products to make repairs to the membrane. Contact Barrett for emergency repair recommendations.

Click Here to download your own digital copy of the “Maintaining Black Pearl® Under Greenroof-Roofscapes®” reference guide.

Looking to hire one of our various Approved Applicators for your next project? Interested in applying to become a Barrett Approved Applicator? Click Here to learn more!

NOTE: All product literature (i.e. technical & safety data sheets, specifications, application instructions, etc.) is currently available to download from the “Resource Library” on our website. 

A well-designed green roof assembly, whether extensive or intensive, involves a series of functioning layers that must succeed in achieving the following:

The success of a green roof relies heavily on the performance of the waterproofing system. In addition to preventing water ingress, waterproofing systems must also be able to provide the building with thermal performance, roof drainage, air tightness & vapor control, and protection from any structural damage caused by root penetration. To ensure that the waterproofing membrane is protected, these systems will typically include a root barrier.

Root barriers can be used to create a protective barrier, either chemically or with a physical sheet, between the vegetation and the waterproofing membrane to protect from potential roof penetration. Physical barriers are made from dense, inorganic materials that will not break down due to bacterial activity or allow roots to penetrate. Chemical barriers contain a compound that stunts root growth on contact and therefore do not allow roots to penetrate the surface of the waterproof membrane.

Today, root barriers installed on green roofs are most commonly made of low and high-density polyethylene, often abbreviated to LDPE and HDPE. This doesn’t come as much of a surprise, especially when considering that HDPE makes up 47% of the material in all plastic milk, water, and juice bottles in the U.S. 

In addition to being a lightweight, pliable, heat weldable, and fully recyclable material, HDPE also offers outstanding tensile strength, moisture resistance, and the ability to withstand extreme temperatures. Naturally, it has proven to be a great material for green roof root barriers.

Barrett offers a number of root barriers to be used with our Greenroof-Roofscapes®, each offering their own features and benefits based on their recommended application.

Root Barriers for Low Profile (Extensive) Greenroof-Roofscapes®

RB20 (20 mil) is the most common root barrier product used for extensive green roof systems. It is a low-density polyethylene sheet that is ideal for systems that have typical green roof plants such as sedums, which have shallow roots and will not present a lot of penetration pressure.

Root Barriers for High Profile (Intensive) Greenroof-Roofscapes®

RB30 (30 mil) is a high-density polyethylene sheet most common in intensive green roofs and roof gardens that will have more aggressive and larger plants like perennials and grasses. The thicker sheet provides additional protection and peace of mind that roots will not penetrate.

Root Barriers for Specialized High Profile (Intensive) Greenroof-Roofscapes®

RB40 (40 mil) is a heavy-duty high-density polyethylene sheet that is recommended when very aggressive rooting plants are installed. This product has been used effectively with bamboo, but we recommend caution when installing bamboo on any roof due to the aggressive nature of the root system. 

*For questions regarding RB40 applications, please contact a Barrett technical representative directly.

All Barrett root barrier products are installed in a similar manner, typically lapping the proceeding sheets a minimum of 12 inches and taping all joints with Barrett’s RB 25 Seam Tape. The barrier is to be turned past the top of the growing media to avoid roots growing around the edges of the sheet. Taping the edges is an extra measure of assurance.

These products are not biodegradable when covered and are intended to provide protection from root penetration during the life of the green roof assembly. This type of root barrier is FLL compliant. Similar to ASTM in the United States, the German FLL is an organization that has been developing and standardizing green roof technology for over 30 years.

When properly installed within one of our hot asphalt RamTough 250 and/or cold asphalt Black Pearl® Greenroof-Roofscapes®, these root barriers provide a comparatively inexpensive solution for membrane protection without compromising performance or quality.  With warranties available for up to 20 years, the solution for any green roof assembly is Barrett’s Greenroof-Roofscape®.

NOTE: All product literature (i.e. technical & safety data sheets, specifications, application instructions, etc.) is currently available to download from the “Resource Library” on our website. 

If you’ve visited any of the major US cities in recent years, there’s a good chance you may have spotted a new trend being adopted by many of its occupants; Green roofs. 

Whether commercial or residential, more and more buildings throughout our nation’s concrete jungles have begun embracing what many European countries have been doing for years. But why?

WHAT IS A GREEN ROOF?

A green roof system is an extension of the existing roof which involves (at a minimum) high quality water-proofing, root repellent system, drainage system, filter cloth, a lightweight growing medium, and plants. 

WHY GET A GREEN ROOF?

Conceptually, vegetative roofs can turn unused roof space into a park-like garden setting with a keen sensitivity to environmental enhancement. Barrett green roofs are designed around inter-dependent components which function as a natural planting habitat, creating new types of public and private spaces while restoring nature’s footprint on the built environment.

With due respect and integration of Feng Shui design principles, a green roof can be endowed with an indefinable quality providing serenity, balance, and harmony in otherwise lost space, all the while making important environmental contributions.

To make the decision that much easier, we’ve broken down the many benefits into a list: