Sika Lockstop single-component, self-sealing mastic waterstop prevents moisture from penetrating NON-MOVING joints in concrete construction.

Fast and easy to install in all working temperatures, Lockstop requires no special labor skills. Lockstop provides a lasting, watertight bond to concrete surfaces.


Lockstop is manufactured under rigid quality controls and is extruded in 16'-8" rolls backed by a quick-release paper.

  •  Easy to Install - Lockstop requires no special labor skills.
  • Available in Rolls - Speeds installation and minimizes splicing.
  • Quality Assurance - Proper installation provides specifier with greater quality assurance.
  • Lower Material Costs - Lockstop self adheres to Lockstop Primer Adhesive without metal fasteners, rings or wire ties.
  • Applies in Any Weather - Lockstop is quickly applied under most temperature conditions.
  • Flexible - Stays tacky in concrete and bonds to the concrete as it cures.
  • Long Shelf Life - Lockstop has an indefinite shelf life. The flexible seal will not crack, shrink, dry out or change over time.
  • Versatile - Lockstop is versatile for lightweight concrete and areas of minimum clear cover. Can be installed outside rebar to protect steel from corrosion. Lockstop does not spall concrete in these applications.

It is important to note that Lockstop is not an expansion joint material and should not be used as such. Expansion joints must be sealed with a conventional waterstop. Contact our Technical Service Group for additional information on waterstop for expansion or moving joints.


Ideal for use on Non-moving construction joints in concrete applications, Lockstop is perfect for use on:

  • Storage tanks
  • Culverts
  • Pipe (round, oval, flatbase, elliptical and arch types)
  • Slabs-on-grade
  • Retaining walls
  • Foundations
  • Tunnels
  • Virtually any typical cast-in-place application