How to Choose the Right Sealer Mix Design

Paul Raymond / Apr 23 , 2020

Things are starting to heat up outside in many parts of the country, which means the weather is conducive for sealcoating. To execute successfully, you need to select the right sealer formula. That’s because sealer performance is affected by the proportion of the product’s various components. It may sound like complex chemistry, but it doesn’t have to be difficult.

THE BREAKDOWN

Much of asphalt pavement sealers are water-based emulsions that are a mixture of a binder (i.e. refined coal tar, asphalt emulsion, or petroleum distillate), mineral filler (i.e. clay), and water. Many of these pavement sealers are supplied in concentrated form, which require the addition of water, aggregate (sand), and additive (optional) prior to application.  The combination of these ingredients is referred to as the “mix design.”

The mix design is the recipe for the ratio in which ingredients are mixed. To help you determine the best mix design for your jobs, we have compiled general guidelines along with suggested adjustments based on pavement requirements or climate conditions.

It is recommended that you use the information as a general guide and experiment to determine what works best for your unique projects and circumstances.

GENERAL GUIDELINES

Refined Tar Petroleum Distillate Asphalt Emulsion
Sealer Concentrate 100 gal 100 gal 100 gal
Dilution Water 30 – 35 gal
(30 – 35% by vol. sealer conc.)
30 – 35 gal
(30 – 35% by vol. sealer conc.)
25 – 30 gal
(20 – 30% by vol. sealer conc.)
Sand 200 lb.
(2 lb./gal sealer conc.)
200 lb.
(2 lb./gal sealer conc.)
200 lb.
(2 lb./gal sealer conc.)
Additive* 0 – 2 gal
(0 – 2% by vol. sealer conc.)
0 – 2 gal
(0 – 2% by vol. sealer conc.)
0 – 2 gal
(0 – 2% by vol. sealer conc.)
*Additives are optional

ADJUSTMENTS

Below are general adjustments to the mix designs listed above based on pavement use and geographic location.

Low traffic areas
The dilution level can be kept on the low to mid end, and the level of sand could be lowered (i.e. 0.5 – 1 lb/gal) if desired. Generally, 1 – 2 coats of sealer are applied.

Medium- to high-traffic areas
Use of an additive, particularly in higher traffic areas, is recommended. Additive level can be increased (i.e. 2 – 4% by vol. sealer concentrate) for added durability, and / or for increased sand loading. Higher sand loading (i.e. 2 – 4 lb/gal) may be used if desired. An additional +5% dilution water may be added if using a viscosity boosting additive and / or higher sand loading. Generally, two coats of sealer are applied. For high traffic areas such as entranceways and drive lanes, putting down a light primer coat prior to two regular coats is beneficial.

Cooler weather (<60°F)
The amount of dilution water should be kept on the lower end of the spectrum, enough to have a good fluid viscosity but not too thick. Utilizing a quick drying additive (i.e. Rapid Set) will help improve dry / cure rates.

Hot weather (>88°F)
If water misters are not being used to cool the pavement, then an additional +5% dilution water will help sealer adhesion and more even drying/curing. Some additives may help prevent power steering marks.

High humidity
Reduce water dilution amount while maintaining a good working consistency. Including a quick drying additive (i.e. Rapid Set) will help improve dry/cure rates.


If you are uncertain or have further questions about proper mix design, GemSeal is happy to help.  We are available to assist by phone or email whenever you need us.

4 Factors to Ensure Successful Crack Sealing

Ken McBride / Apr 2 , 2020

Pavement faces many opponents including water, ice, salt, and debris.  What’s the best defense? Crack sealing. But, successful results depend on a few factors—timing, material, application, and equipment.

The Right Time

Crack sealant melter machine

Crack sealing is most effective when it’s performed as soon as cracks appear. Deferring the procedure will cause cracks to widen and spread causing more expensive, structural damage. When caught and treated early, the sealant provides a barrier to prevent water and non-compressible materials from entering the cracks which eliminates sub-base erosion, reduces freeze-thaw damage, and improves ride quality.

Being proactive is the first step. Next, consider the job. Where is it located and what type of pavement is it? This will help you determine the best material to apply.

The Right Material

Like sealers or traffic marking paint, not all crack sealants are the same. The type of sealant you use should be determined by the climate. For example, cooler climates require more flexible sealants than hotter climates. Using a softer material in a hot climate could cause tracking of the sealant by vehicle or pedestrian traffic. In hot climates, there is less movement of the pavement surface in general and, therefore, no need for a very flexible material. On the other hand, a flexible material is best for use in a cooler climate — where the pavement will be exposed to greater temperature swings and will have more thermal movement.

Another major factor is the job type. For example, you shouldn’t use a roadway sealant on a parking lot or pedestrian area. Parking lots require a sealant designed for pedestrian foot traffic, turning vehicles, and parked vehicles—usually a stiffer material that loses tackiness when cured. Pavements with less than 20 percent crack density require a more flexible sealant.

The Right Application

Only apply sealant in accordance with the manufacturer’s recommended temperature range, which is typically in air and pavement temperatures above 45°F. Also, be sure no rain is in the forecast.

Prior to installing sealant, widening of cracks or routing may be necessary. This process is recommended on roads with less than 20 percent crack density and can help extend the life of the sealant by up to 40 percent. When deciding between routing and sawing, study the pattern of cracking. Routing can be done with cracks in any direction, but sawing can only be done with straight cracks.

When sealing cracks in pavement with greater than 20 percent crack density, simple cleaning and sealing of the cracks is recommended.

The Right Equipment

To ensure the surface is clean and dry, use a compressor with sufficient pressure and velocity that is also equipped with a water trap to remove particles that could prevent bonding in the cracks.

A heat lance can be used to eliminate bond-destroying moisture. But, any pavement that is saturated with water shouldn’t be sealed. Areas that are damp, discolored due to moisture, or show evidence of frost or dew should be avoided during crack sealing.

With your melter/applicator, fill cracks no higher than 1/8 of an inch above the pavement to help prevent damage from tire imprint marks or snow plows.


For more information or help selecting material and equipment, contact your local GemSeal representative. We’ll help you take care of cracks and achieve the right results!

5 Reasons to Re-Think Your Pavement Sealer

Lee F. Lowis / Oct 1 , 2018

It’s officially fall, but there’s still time to apply sealer in many parts of the country. Perhaps you’re accustomed to refined tar sealers. Or, maybe you like to use asphalt emulsion-based sealers. While both products are very effective, there is another option available. Here are five reasons why you should re-think your pavement sealer product selection prior to your next project.

5 Reasons to Re-Think

  1. Get the best of both worlds. Refined tar sealers are increasingly under scrutiny – despite a growing body of science which supports their safe use. As a result, everyone seems to want an alternative to coal tar, yet still have all the same benefits. For that reason, GemSeal developed Black Diamond™, a sealer that combines the performance of refined tar sealers with the benefits of asphalt-based sealers.
  1. Apply with confidence. Like our other quality pavement products, GemSeal manufactures Black Diamond using a colloid mill process, not a batch process, to ensure consistency. It was tested for over two years before entering the market at the beginning of 2014. And, samples continue to be evaluated hourly and daily at each of our plant-operated labs.
  1. Avoid application restrictions. Black Diamond contains zero refined tar, making it acceptable for use in many areas that have banned coal tar.
  1. Provide better coverage and superior color stability.
    Black Diamond is more durable than asphalt emulsion (it wears 2-3 times longer than traditional asphalt emulsion sealers), provides better coverage, and improves chemical resistance over standard asphalt emulsion sealer. Plus, its natural pigment resists oxidation enabling superior color stability. Black Diamond also provides performance closer to refined tar sealers through ease of application, fuel resistance, and toughness against power steering marks.

Scrub and Chemical Tests

  1. Satisfy your crews and clients. Crews love working with it because there is no irritation due to its unique chemistry (nearly zero VOC). It can be applied at lower outside temperatures, has a better coverage rate, and a higher dilution rate than most traditional asphalt emulsion sealers, which saves money for you and your clients.

Additional literature or videos are available for download or you may contact your local GemSeal sales representative.

Why You Should Give Sealcoating in Cold Weather the Cold Shoulder

Paul Raymond / Mar 6 , 2018

cold weather impacts sealer applicationPeeling, flaking, and discoloration are not what you want to see on the surface of pavement. To help avoid these issues, tune in to the weather forecast before you apply sealer. That’s because weather conditions can greatly affect the performance and durability of applied sealer.

What’s the best temperature to seal a driveway?

The ideal conditions for application are during the day when pavement and ambient temperatures are at least 50°F and rising, and no rain is forecasted for 24 hours. If these recommendations are not followed, the procedure will not yield desired results.

How does administering your driveway sealer in low temperatures affect final application?

Applying sealer below recommended temperatures can lead to issues such as tracking, power steering marks, discoloration, and reduced durability.  As pavement temperatures fall below 50°F, it becomes more difficult for the sealer to adhere to the pavement.  The binder in sealer applied in colder temperatures also becomes harder and more difficult to fuse and stick together to form an effective film.  Poor adhesion and film formation will cause the sealer to come off more readily.

What happens to asphalt pavement sealers when applied below 50°F?

Asphalt pavement sealers are water-based emulsions.  During the drying and curing process, water evaporates off and the “solid” ingredients come together to form a film and adhere to the pavement.  The solid ingredients come closer together as water leaves the system until they touch and “coalesce,” which means they flow into each other to form a bond (particularly the binder).  The binder in the sealer is the “glue” that holds the film together (known as cohesion), as well as sticking to the pavement (known as adhesion).  As the temperature lowers, the binder becomes harder, making it more difficult to cohere and adhere to the surface.  In severe cases this may result in the film cracking and flaking off.  In milder cases the film may exhibit discoloration, increased power steering marks or tracking, and lower durability.

How does cold weather affect drying?

The evaporation rate of water slows down as temperature decreases.  The drying rate of sealer at 50°F is considerably slower than it is at 80°F.  For instance, it may take sealer twice as long to dry at 50°F compared to 80°F.  Other weather-related factors that will slow dry rates are high humidity, overcast conditions, and a dew point within 5° of the temperature. When a pavement sealer retains water, it will stay soft and be more vulnerable to peeling, tracking, and power steering marks.


Rather than putting on more coats (of sealer) in cold weather, reserve this time for wearing them only.  Warmer temps will be here before you know it.  Spring—and sealer season—is in the air!

3 Reasons Why You Should Use a Pavement Specification

Lee F. Lowis / Jan 10 , 2018

pavement specificationManaging the vast area of asphalt outside your properties requires a good pavement maintenance plan. A good plan consists of three primary maintenance procedures: crack sealing, sealcoating, and lot marking.

But, the most effective plan is one that specifies the right products and application processes so you get the right results every time.

The Benefits Go Beyond the Surface:

  1. Extend Lifespan. When the right products are specified and properly applied, and each service is performed routinely, pavement usability and lifespan are extended. Work with your material supplier to select the right products for your properties and ensure proper application by hiring an experienced, reputable contractor.
  1. Save Money. A pavement specification enables you to obtain multiple bids from contractors on an apples-to-apples basis, since it will outline how the work is to be performed. In addition, hiring the right contractor to perform routine maintenance delays more costly structural repairs, which means better cash flow for your business.
  1. Peace of Mind. With a specification to follow, your contractor knows exactly how to prepare the surfaces to be maintained, which materials to use, the proper weather and temperature conditions for application, and the safety procedures that are necessary to minimize job-site risk.

A pavement specification may vary from site-to-site based on unique factors of the region including location, pavement condition, and climate. It is imperative to understand the specific factors within your portfolio that impact which materials, equipment, and application process should be used to achieve successful results.

To help guide you in preparing a specification, please download our article entitled The Right Products and Process Extend Pavement Lifespan. By educating yourself, you can be certain you’re making the best decisions concerning your pavement assets.

Ready to get started? GemSeal has helped property managers nationwide develop maintenance programs and pavement specifications. We’re happy to assist you, too; contact us today!

Material Specification for Local Asphalt Maintenance Projects

Ken McBride / Aug 22 , 2017

Material Specification

All pavement products are not created equal or designed to be a one-size-fits-all solution. From location and weather to application, there are many variables that impact pavement condition and product performance. Yet, materials for projects in the private and public sector are typically specified by engineering firms and building contractors. They often create these specifications based on materials used in past projects or simply because they are in the “comfort zone” of the individual creating the specification. In many cases, these are not the most suitable materials available for the project.

That is because materials and application strategies are constantly changing, and it is difficult for individuals who work outside of the asphalt maintenance industry to stay up-to-date on every new innovation. Using the right products, however, is a critical factor in the success of any paving project. This decision can be the difference between a long-term solution and a quick fix that will need further repair down the road.

How to Select the Right Product for the Job:

  1. Consult a pavement product manufacturer in the same market as your jobsite or sites. With convenient locations around the country, your GemSeal team is knowledgeable on local industry trends, environmental concerns, material restrictions, and newly available products. As an illustration, lot marking paint used in California must adhere to different VOC limits than paint used in many other states.
  2. With your manufacturer’s help, select a product that properly addresses individual site conditions, unique to the region in which sites are located. This will ensure optimal product performance and reduced pavement defects. For example, a crack sealant suitable for the Texas heat in summer will have different characteristics than one designed for use in colder climates.
  3. Create a specification to outline how the work is to be performed. It should cover how to prepare the surface, which materials are to be used, how to apply the materials, and safety procedures. In addition, product documentation including technical data, application specs, and safety data sheets can be supplied to help support the decision and educate all parties involved on why particular products are recommended over others. Ultimately, a specification is a record that can be referenced for future projects, saving time and money while providing peace of mind.

If you have questions regarding material selection or application specifications in your area, please contact your local Gem­Seal representative.  As we like to say, the right product and the right process give property owners the right results!