Concrete Joint Sealer vs. Concrete Joint Filler

When it comes to concrete joints, is there any difference between sealers and fillers? You might be surprised to learn that yes, there is a difference. These two masonry tools are used for different applications in masonry repair, but they’re both important components of joint repair. This week, we’ll talk about the differences between sealer and filler, and how they’re used in masonry repair.

Concrete Sealer

Concrete sealer is soft. This allows it to expand and contract in the joint as the concrete expands and contracts naturally due to temperature changes. The sealer prevents water, ice, dirt, and other from debris from getting into the joint, where it can cause water damage, or freeze and causing cracking. Sealer also prevents intrusion from under the concrete slab.

The best sealers have the following characteristics:

  • The ability to create a strong bond to the concrete.
  • Impermeability, in order to prevent the ingress of water.
  • The ability to handle repeated expansion and contraction.


Sealer should be applied once the concrete slab has undergone its natural shrinkage. Sealers will need to be checked at least once annually and assessed. If the sealer has degraded, it will be necessary to reseal in order to prevent damage.

expansion joint sealant

Concrete Filler

Concrete filler on the other hand is hard. The goal of filler is to support the edge of the joint when it needs to bear a lot of weight. Note that filler is only used with saw-cut joints. Joints with a rounded tooled edge cannot use filler.

Fillers, like sealers, should only be applied after the concrete slab has shrunk. This can take up to a year, but fillers will not be effective if applied before this process is complete. Fillers should also be inspected annually to determine if they need to be reapplied.

Would you like to know more about the products we use for masonry repair in Baltimore? Check out our blog on some of the vendors and products we trust to provide quality repair services. This includes the Sika product line, Loxon concrete and masonry products, and a number of well-known local vendors.

About Consolidated Coatings Inc.

Consolidated Coatings is a full service building restoration contractor operating in Maryland, Virginia, and Washington, D.C. Since 1979, we’ve provided professional restoration of commercial, industrial, and historic buildings across a range of disciplines. These include masonry restoration, concrete restoration, decorative concrete, industrial and floor coatings, EIFS, and waterproofing. Follow us on our blog for weekly posts on industry-related topics. If you have any questions, please contact us at 410-574-6504.

This entry was posted on Friday, February 20th, 2015 at 3:59 pm.