Should You Seal Or Fill Asphalt Cracks?

Should You Seal Or Fill Asphalt Cracks

Sealing or filling asphalt cracks is directly dependent upon the extent of asphalt cracks measured in width. Generally, asphalt sealant is used for cracks that measure less than ¾ of an inch in width and crack filling is used for cracks that measure wider than ¾ of an inch. Crack filling is generally reserved for older pavement in need of more serious repairs while crack sealant is seen as a preventative maintenance method that extends the life of asphalt.

Overtime the process of treating asphalt cracks has evolved from using asphalt cements to fill in cracks to the use of specially engineered sealant materials.

Sealing Vs. Filling

In order to determine if you should seal or fill asphalt cracks it’s important to understand the uses of each treatment process.

What Is Crack Sealing?

Crack sealing is a localized treatment method that blocks water and debris from getting inside cracks. In order to properly seal cracks all debris must be blown away. A saw or router may also be used to cut out a reservoir, which is then filled with sealant.

The best candidates for sealant are cracks that measure less than ¾ of an inch in width and include limited edge deterioration. In order to seal a crack the router or saw width must be able to touch both sides of the crack.

There are three unique approaches to sealing cracks including:

  • Clean and seal
  • Saw and seal
  • Rout and seal

Local highway agencies often include regular crack sealing as a part of routine maintenance in order to prevent minor cracks from resulting in larger problems when moisture or debris seep inside. You may not immediately notice the differences but the benefits show up over time as the pavement will last longer and show less wear and tear compared with unsealed pavement.

What Is Crack Filling?

Crack filling is a treatment used for more severe cracks in pavement that will not benefit from sealant alone. The best candidates for filling are cracks that measure more than ¾ of an inch in width. Full-depth crack repair is a localized treatment method focused on repairing cracks that are past the point of being helped by sealant. When a crack is too wide the saw width or router will not touch both sides of the crack, and as a result sealant is not productive.

Unlike sealants, the purpose of crack filling is not to prevent water from entering the crack in the same way as sealant. Although, fillers do offer some protection to cracks as well as coat crack edges and reduce oxidation rates. 

Crack filling can be conducted at any time of year but is commonly conducted in the winter when cracks are open to the fullest extent. Depending on the type filler used, filled cracks have a life expectancy ranging anywhere from a couple months to 2-3 years. 

Materials Used For Sealing & Filing Cracks

There are a variety of materials used to fill and seal cracks, including asphalt cement and liquid asphalt, both of which are not flexible but are very temperature susceptible. As a result, these two materials are only to be used for non-working cracks. Adding mineral fillers and fibers generates little elasticity to asphalt and does not impact temperature susceptibility too much.

Low-modulus rubberized asphalt is a crack sealant that is used for cracks with a ¾-inch x ¾-inch reservoir size and little overband.

Rubberized asphalt is used as both a sealant and filler in situations when wider reservoir widths are necessary.  It can also be used for the clean-and-seal method.

Crumb rubber is an effective crack filler especially in the early spring or late fall when cracks remain wide open. Crumb rubber is known to crack in the winter but it actually repairs itself come warmer weather.

Asphalt emulsion is crack filler used to coat crack edges as well as to fill in some of the crack. Emulsions measure 33% water, and as a result the quantities will shrink as they undergo the curing process. They should only be applied during warmer months.

Asphalt cement is crack filler used to coat the edges of cracks as well as fill them in. This material tends to go brittle in the winter and is prone to tracking when the weather is warmer.

Cutback asphalt is crack filler similar to emulsions in that it is often used as the primary coat for crack edges. While cutbacks can be applied in the winter, they are not as safe or readily available as emulsions.

Interestingly, the materials used to fill cracks tend to be more affordable than materials used to seal cracks.

For all asphalt cracks, big and small, Kleenco Construction provides guaranteed superior results. Contact us today to get a competitive quote on your next project!