Friday, April 2, 2021



The list of materials utilized as waterproof coatings through the ages is a long one. For centuries, asphalt-based products such as pitch and tar were the only option. In the 20th Century, a series of other alternatives established, including paint, epoxy, fiberglass and vinyl esters.

The most recent coating technology is polyurea. Established in the late 1980s for the automotive market, this material is now used in a broad variety of applications. Use of this product as commercial waterproofing has actually increased in appeal in the past years due to its fast-curing, rust- and abrasion-resistant qualities

Garry Froese, owner of ArmorThane explains, "Polyurea was invented in the early 1980s when a less moisture-sensitive type of polyurethane was preferred. By changing the hydroxyl group in the urethane with an amine group, a product we now call polyurea was formed. It has considerably less sensitivity to wetness than other urethane-based coatings."

Of the two most typical types of polyureas, fragrant polyureas are without a doubt the most common. Froese calls them "the workhorse of the industry providing a wide range of physical attributes for numerous usages." In fact, the only characteristic, these coatings do not supply is UV stability.

A second solution, aliphatic polyureas, utilizes various chemistry to supply UV stability. This added advantage comes at a rate as aliphatic polyureas are normally twice the rate of fragrant polyureas.


One factor polyurea coatings are exploding in the appeal is the wide array of positive attributes they show.

The market site,, opens with a strong statement. "Virtually no other coating can compare to polyurea when it comes to achievable physical residential or commercial properties," it checks out. "Polyureas can be formulated to accomplish a remarkable range of properties from high elongation to superior tensile strength to difficult or soft, all based on how the products is created and properly used."

It adheres tenaciously to a variety of various substrates (concrete, metals, wood and more) without primers and in a large range of temperature and humidity environments.

Perhaps its biggest benefit is that it establishes incredibly quickly, allowing the applicator to develop a finished density in a single pass. This enables the owner to put the center back in service sometimes faster than conventional coatings, saving days and even weeks of earnings lost to down-time.

Froese says, "Thicknesses can range from 20 mils to 500 mils in one application. Treatment times vary from rapid to two minutes permitting fast return to service."

As a fast curing, thick movie coating, polyurea is a sensible service when smooth, resilient membranes are required for waterproofing. Extra attributes such as slip-resistant ingredients and surface textures can also be included. It can be colored and is even available in a potable-water-approved formula.

With such a large range of efficiency characteristics, the series of suitable applications is likewise broad. Tank linings, secondary containment and bridge coatings are a few of the most popular usages, however the application possibilities are unlimited.

Polyurea can be utilized to waterproof both the joints and the surfaces of numerous concrete structures, such as this tank near Huntsville, Alabama.

The innovation has actually been utilized successfully on pedestrian decks and parking lot, tanks, tunnels, water tanks, slurry pits, and floor covering. It can likewise be used as a joint filler/caulk.

Polyurea was initially used as a truck bed liner to form a permanent watertight layer. The same durable and abrasive-resistant characteristics that make it ideal for lining pickup beds and discard trucks make it appealing for difficult waterproofing tasks.

The tanks at wastewater treatment plants, for example, are exposed to turbulence, disintegration, and large amounts of hydrogen sulfide gas as the contents are screened, combined, and dewatered.

Polyurea coatings can supply the abrasion, chemical, and impact resistance required, and restore the plant to operating condition much faster than lots of other contending systems.

For bridges and other applications exposed to vibrations and movement, the inherent versatility of polyurea is an included benefit over thinner, less flexible coatings like epoxy.

Polyurea does have a few downsides. Froese notes that the equipment required to apply polyurea coatings can be expensive. It can range from $15,000 to $50,000 or more. Totally geared up mobile platforms can cost more than $100,000.

The material also costs more than some alternatives. Froese states that preliminary costs are higher than epoxies, but given that polyurea coatings can last three to five times longer, they are rather cost-effective over the life of the coating.

Similar to any waterproofing material, it can stop working if applied incorrectly. Surface preparation-- generally sandblasting or priming-- is important for a successful application. Many failed polyurea coating jobs have little to do with the polyurea itself, but rather, inadequate or poorly executed surface preparation.

About 54,000 sq. ft. of polyurea waterproofing was applied to this potable water tank at the U.S. Army's Redstone Arsenal.

Most polyureas utilized for waterproofing are spray-applied with plural component spray devices.

It's normally delivered as a two-part system, with the amine resin blend and isocyanate product supplied in 55-gallon drum sets. As soon as in use on the jobsite, they are transferred from 55-gallon drums to separate tanks in the spray devices where they are heated to the proper temperature level (140 ° F-160 ° F). The machine then delivers the isocyanate and polyol resin through heated pipes to the spray gun in an accurate ratio (generally 1:1).

Polyurea has a set time that is determined in seconds, so it's crucial that the chemicals don't mix till the immediate prior to they leave the gun. Otherwise, the product will set up and harden inside the gun.

Numerous makers offer mobile spray rigs that consist of all of the tools and equipment needed, installed on either a trailer or truck bed.


Belleville, Ontario, Canada is a city of 50,000 situated the north shore of Lake Ontario, straddling the major highway connecting Toronto to Ottowa and Montreal.

This critical highway and the surrounding buildings were at risk of flooding due to the fact that the waterproofing membrane on a neighboring dam had actually stopped working and substantial quantities of water were saturating the dam and surrounding soil.

The McLeod dam and floodwall was integrated in 1978 to secure downtown Belleville from ice-related flooding. Nevertheless, the original PVC liner had decayed to the point that water was permeating into the basement of neighboring services and the hydropower turbines were impacted.

Ontario Conservation, which handles the residential or commercial property, took on the job to restore the waterproofing membrane. But because the floodwall ran under the local roadway, elimination or repair of the PVC liner was not feasible. The repair's look was likewise a concern. They wanted to maintain the rocky slopes of the reservoir and the total natural appeal of the area.

Ontario Conservation selected to use geotextile fabric and a spray-applied, fast-set polyurea. ArmorThane's ArmorLiner got approval. This product is a pure polyurea created for severe outside conditions where water, humidity or low-temperature levels might exist. It develops a smooth, monolithic barrier.

In 2011, the task got underway. After the dam's water level was decreased, loose debris and large rocks were removed from the website. A concrete curb was set up at the base of the embankment, which served to secure the lower end of the geotextile fabric. A trench keyway along the top of the tank holds the upper edge of the liner in place.

The sheets of geotextile were then presented, seamed together, connected at the top and bottom keyways and sprayed with ArmorThane's product to a density of 80 -100 mils (2 -2.5 mm) in a single pass. Finally, gravel and larger stones were layered above the polyurea/geotextile fabric to safeguard it from UV deterioration and imitate the look of a river bed. The water level was raised gradually to reach its typical level, and the tank was put back into operation.

The $700,000 job took about 4 weeks to complete.

3 years after the task, Ontario Conservation engineers are still extremely happy with the results. "It is carrying out to expectations and was an exceptional method to remediate our embankment," said Bryon Kennard, Ontario Conservation's water resources supervisor. "The old liner had stopped working and although this alternative was more costly, we felt it was more long-lasting and would stand up to the harsh environment. We put riprap directly over the surface area of the liner with heavy machinery and it easily stood up to the placement."

With routine maintenance, Ontario Conservation expects to get at least 40 years of service life from polyurea lining.

If you would like to know more about ArmorThane's product lines, click here.

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