February 2003
ASPHALT EMULSION VS. ACRYLIC RESURFACER
The debate concerning the use of asphalt emulsion filler coats versus
the use of acrylic resurfacer began in 1979 with the first affordable
acrylic resurfacer. Prior to that contractors and acrylic suppliers had
to make due with sand filled asphalt emulsion filler coats (SFA). This
type of product was used because it was inexpensive.
Today, affordability is not the issue that faces most contractors; performance for a demanding buyer is the challenge.
The reasons contractors, suppliers and owners specified Acrylic Resurfacer over SFA are extensive. Some are based on the benefits of Acrylic Resurfacer, others are based on the shortcomings of the SFA. It is informative to review the reasons.
Asphalt Emulsion Filler = SFA
Acrylic Resurfacer = AR
SFA is based on slow set anionic asphalt emulsion that may not be stable
for prolonged storage. It is prone to settlement and spoilage.
AR is formulated with synthetic acrylic resins for long term stability.
In-can
preservatives provide long term stability
SFA - Asphalt based products are quickly degraded by UV light thus weakening their elastic and tensile properties.
AR is formulated with acrylic resins known for their UV stability.
SFA is formulated with clay fillers that tend to absorb moisture and
swell, eventually
weakening the coating.
AR does not use clay fillers that absorb moisture.
SFA does not "breath". Subsurface moisture tends to be trapped creating significant potential for blistering.
AR and other acrylic are known for their capability to allow the surface to breathe.
SFA is very thermoplastic, it softens in higher temperatures leading to tears in
the acrylic finish on hot days. It becomes brittle at prolonged colder temperatures.
AR is much more stable in hot and cold temperatures.
SFA is very difficult to clean up. Petroleum solvents are normally required to clean tools and workers. This can lead to potential dangers on a job site.
AR is easily cleaned up with soap and water.
SFA is not recommended for concrete surfaces.
AR may be used on either concrete or
asphalt.
SFA - Most manufacturers of SFA suggest/require that it be rolled with
a mechanical steel wheeled roller after application to achieve
density.
AR does not require rolling after application.
SFA - Most manufacturers suggest a 24 hour "curing time" prior to application of the acrylic color coating.
AR may be recoated in 1-2 hours after application.
SFA - Some SFA brands are available in only one surface texture thus
limiting contractor capability to customize the underlayment texture.
AR may be blended with local sands to meet the individual site requirements.
SFA is manufactured by firms whose primary asphalt business is general-purpose
sealing. Most specifications require the entire system to come from one
manufacturer.
AR is produced by the color manufacturers.
SFA - The USTC & TBA guide specs do not recommend SFA for court surfacing unless it is specifically noted by the acrylic manufacturers.
AR is the standard for the acrylic surfacing industry.
SFA is the weakest layer in a multi- layered coating system. It will become the point of failure in the future. Creating a problem that demands expensive corrective measures
AR is similar in strength to the rest of the coating system. It prevents
differentials in strength and extends the life expectancy of the coating/asphalt
system.