Floor & Joint RepairS olution

Prime Practices

Filling Control Joints with Semi-Rigid Polyurea

Call: 1-800-321-7212

Scope of Work: Cleaning and filling control joints in concrete slabs on grade to prevent edge deterioration



Concrete slab edge deterioration due to lack of semi-rigid joint filler in control joints.

Surface Preparation

  • Clean joint sidewalls with wet or dry cut saw (dry cut is preferred) with proper dust collection.
  • Saw cut to a minimum of 1”
  • Clean and remove all dust, water and slurry from the joint.
  • If wet cut, allow joint to dry before installation of polyurea.
  • Make sure all side walls are clean and dust free.


  • Once clean and dry, fill with Joint Shield 5500 Polyurea 95A, a semi-rigid polyurea, slightly overfilling the joint. For wide joints, you may fill the portion of the joint below the saw cut with oven-dried sand (Prime Blend) to control seepage.
  • Never use backer rod.
  • Allow material to harden 30 minutes, depending on temperature, and remove excess material with a razor blade or grinder flush with the surrounding floor surface.

Safety Considerations

  • Carefully read SDS prior to handling any chemical
  • Follow OSHA or comparable guidelines, including those for protection from airborne silica.
  • Always wear safety goggles when drilling, grinding, flushing, injecting or handling resins.
  • Always wear protective clothing, chemical resistant gloves and safety goggles at all times when handling resins.
  • Make sure no loose clothing can come into contact with moving mechanical equipment.
  • Keep first aid kit (eyewash, bandages, etc.) present on site with easy access.

Materials List

Polyurea-based joint filler Joint Shield 5500 Polyurea 95A
Prime Eco Flush (pump cleaner)

Equipment List

  • Concrete saw with diamond blades and dust collection
  • FlowMaster pump, the Patriot pump or another positive displacement two-component pump with appropriate gun or wand
  • Pneumatic cartridge gun
  • Dustless vacuum
  • Razor and blades to shave or grinder
  • Clean empty pails
  • Rags
  • Broom