About the Dumbbell Profile
Dumbbell waterstops are specified for non-moving construction joints in concrete structures — joints where continuous bonded reinforcement carries through the joint and the waterstop is exposed to negligible or no movement. Without a centerbulb or tear web, the profile lies flat across the joint, with enlarged bulb-shaped ends on each flange that anchor the waterstop into the concrete. The result is a continuous diaphragm intended to prevent the passage of liquid through the joint, with the dumbbell ends providing mechanical interlock at the outer edges of the profile.
Dumbbell profiles are an alternate to flat ribbed shapes for non-moving joints. Sika literature notes that ribbed shapes provide better sealing characteristics, so engineers and specifiers will sometimes prefer Flat Ribbed where sealing performance is the priority. The choice between the two often comes down to project specifications and engineering preference. Dumbbell waterstops are produced in widths from 4 inches up to 9 inches across a range of weights and head pressure ratings, with the appropriate size depending on the project’s hydrostatic head, concrete thickness, and specification.
Typical Applications
✓Commonly Specified For
- Non-moving construction joints
- Joints with continuous reinforcement through the joint
- Foundation walls and retaining walls
- Water and wastewater treatment plants
- Reservoirs, tunnels, and containment structures
- Slabs-on-grade with continuous reinforcement
- Potable water contact applications
- Specifications calling for a dumbbell-style profile
→Other Profiles May Be Considered When
- Better sealing characteristics are desired — see Flat Ribbed
- The joint will experience movement — see Dumbbell with Centerbulb or Ribbed Centerbulb
- Large joint movements are expected — see Tear Web profiles
- The application is a slab-on-grade joint — see Base Seal
- The joint is at an existing concrete face — see Retrofit profiles
Profile selection should always be verified against project specifications and engineering requirements. Contact us if you’d like assistance reviewing options for your application.
Available Sizes & Versions
Sika Greenstreak produces dumbbell waterstop in a range of profile sizes to suit different joint widths, concrete thicknesses, and head pressure ratings.
Profile 741
Width: 4″
Thickness: 3/16″ web
Weight: 0.47 lb/ft
Head Pressure: 65 ft (194 kPa)
Dumbbell End: 3/8″
Profile 746
Width: 6″
Thickness: 3/16″ web
Weight: 0.71 lb/ft
Head Pressure: 75 ft (224 kPa)
Dumbbell End: 3/8″
Profile 748
Width: 6″
Thickness: 3/8″ web
Weight: 1.51 lb/ft
Head Pressure: 125 ft (373 kPa)
Dumbbell End: 3/4″
Profile 751
Width: 9″
Thickness: 3/8″ web
Weight: 2.18 lb/ft
Head Pressure: 150 ft (448 kPa)
Dumbbell End: 3/4″
Profile 752
Width: 9″
Thickness: 3/8″ web
Weight: 2.55 lb/ft
Head Pressure: 150 ft (448 kPa)
Dumbbell End: 1″
Sizing considerations generally include hydrostatic head, concrete cover, and any project-specific specifications. Contact us if you’d like help cross-referencing a profile against your spec.
Installation Overview
Dumbbell waterstops are typically installed prior to concrete placement using split formwork. Heat welding is generally the recognized method for splicing PVC waterstop, and factory-fabricated transitions are widely recommended to reduce the risk of failure at intersections. Always refer to the manufacturer’s installation guide and project specifications for complete instructions.
Center the waterstop over the joint with roughly half the profile projecting into each pour.
Tie off the outer flange to adjacent reinforcing steel using hog rings or similar methods.
Heat-weld butt splices in the field. Factory fabrications are generally recommended for changes of direction.
Place and consolidate concrete around both flanges to encapsulate the waterstop fully.
Frequently Asked Questions
+What is a non-moving joint, and why use a dumbbell profile there?
A non-moving joint is a construction joint where 100% of the bonded steel reinforcement runs continuously through the joint, exposing the waterstop to negligible or no movement. Because there’s no expected flex, a centerbulb or tear web isn’t needed — the joint won’t open enough to require one. Dumbbell profiles are one of two profile families commonly used in these applications, with the enlarged bulb-shaped ends providing mechanical anchorage at the outer edges of each flange. Flat ribbed is the other common option.
+Dumbbell or flat ribbed — which should I use for a non-moving joint?
Both are suitable. Sika literature recommends ribbed shapes when better sealing characteristics are the priority — the series of ribs along the flange creates more mechanical interlock with the surrounding concrete than the single bulb at the edge of a dumbbell flange. That said, dumbbell profiles are widely specified, easy to install, and remain a standard choice for non-moving joints, particularly when the project specification calls for a dumbbell shape by number. If the spec leaves the choice open, ribbed shapes are often the more conservative pick.
+Which dumbbell profile should I specify?
Selection typically comes down to width, hydrostatic head requirements, and concrete thickness. The 741 (4″) and 746 (6″) are lighter profiles for lower head pressure applications, rated for 65 and 75 ft of head respectively. The 748 (6″) is a heavier 6″ option rated for 125 ft. The 751 (9″) and 752 (9″) are the heaviest profiles, both rated for 150 ft of head pressure — the 752 has larger 1″ dumbbell ends versus the 3/4″ ends on the 751. If your specification calls out a profile by number, that’s the deciding factor — otherwise, project-specific requirements should drive the final selection.
+What if my joint actually does move?
Dumbbell profiles (without a centerbulb) are not appropriate for movement joints. Without a centerbulb or tear web to absorb joint flex, a flat dumbbell profile placed in a moving joint can go into tension and fail. If the joint is designed to accommodate drying shrinkage, thermal expansion, settlement, or live load deflections, a movement-joint profile such as Dumbbell with Centerbulb, Ribbed Centerbulb, or Tear Web should be specified instead.
+Are factory-fabricated intersections necessary, or can they be done in the field?
Field-fabricated intersections are widely cited as a leading cause of waterstop performance issues. Sika recommends factory-made fabrications for L’s, T’s, crosses, and other changes of direction. Field welding is generally appropriate for straight butt splices between runs of waterstop. The project specification will typically indicate which approach is required.
+Are dumbbell profiles suitable for potable water structures?
All Sika Greenstreak PVC waterstop profiles, including each dumbbell size, are NSF/ANSI 61 certified for potable water contact. This makes them appropriate for many applications such as finished water reservoirs and treatment plant clearwells, subject to project-specific requirements.
+How is dumbbell waterstop welded in the field?
PVC waterstop is typically heat-welded using a thermostatically controlled splicing iron. The two ends are squared, butted against the heated blade until the PVC begins to melt, then pressed together and held until cool. Sika offers a Waterstop Welding Certification Program for contractors seeking formal training, as weld quality has a significant impact on long-term performance.
