At first glance, seal coating asphalt aggregate has a few simple objectives. However, when we dive deeper into the fine details, we learn that each of the methods of application are not created equal and do not provide equal protection. The objective behind seal coating is to protect from traffic erosion as well as water penetration. Applying with a squeegee, specifically, a squeegee machine is one method that protects well against water penetration but lacks in other areas. Spray application has particularly strong protection from traffic erosion. A Third method, hand squeegee, is only used for areas the squeegee machine cannot reach such as curbing or tight spaces.
To help avoid premature wear from weathering of water and UV light, the aggregate pavement squeegee application is recommended. With this method, the sealer is heavily over-applied before it is spread evenly across the asphalt with a squeegee machine. Filling pours reduces the surface vulnerability to freezing water that sits in these pours. A squeegee machine application uses between 33% to 50% more sealer volume per square yard (depending on the condition of the asphalt), which helps to maximize the protection your asphalt receives. Due to the additional material left on the pavement, there is an additional cost associated with this method of application. Two coats of sealer via squeegee machine leaves the asphalt vulnerable on the surface. This is because the squeegee pulls most of the excess sealer from the surface while leaving it in the pours, which makes the asphalt more vulnerable to traffic erosion or friction. This will show up in the form of light-colored pavement where the sealer has been eroded and no longer present as surface protection. Since there are only a few contractors in Central Ohio who own a squeegee machine and have a qualified operator of the machine, we always try to make sure we bid competitively, and will usually offer the squeegee option when we feel it is an appropriate method for your parking lot. We do not recommend a squeegee machine application on asphalt that is moderately to severely deteriorated. Squeegee application is best suited on new asphalt that has never been sealed or has been well maintained but has exposed pores.
To prevent excessive erosion from traffic friction, the second coat of sealer applied with spray equipment is recommended due to the way that the material can be evenly applied to the asphalt. With no squeegee to manipulate the sealer into pours, the sealer forms in an even layer across the top or peaks of the asphalt. However, two spray coats will leave your asphalt pavement vulnerable to wear and tear because only the peaks of the asphalt have been completely covered with sealer. The symptoms of premature freeze damage can show up in the form of an excessive amount of pebbles/aggregate that ravel out of the asphalt. This aggregate is what makes up the initial surface of your asphalt.
All things considered, the best application method includes both a squeegee machine and spray applications. The first coat should be applied by squeegee machine to fill in the pours vulnerable to freezing water, and the second coat should be applied by spray application to maximize protection against traffic erosion and retaining a dark color for years to come. The combination of the two application methods provides the ultimate protection for your asphalt.
Therefore, the cheapest package may not be your best value in the long run. At Hill’s Blacktop & Concrete, we understand that budgeting is an important part of your business, so we always work to fulfill your needs in the most cost-effective way. Sometimes, that is a squeegee machine and spray combination, and sometimes, it is two coats of spray. However, we promise that any combination you choose will be completed to the best of our professional ability.