Concrete expansion joint filler: backing or sealant?
Start with the joint detail before choosing a cartridge.
For sealing an exterior concrete expansion joint, Vulkem 116 is an option on concrete that isn't damp, green or contaminated. Dymonic 100 also lists expansion joints and can adhere to damp or green concrete. Need backing material or a full-depth slab filler? The supplied sealant sheets don't settle that choice. Confirm what the joint detail calls for before buying.
What are you being asked to fill?
Check the drawing or specification for separate backing and sealant requirements. If the purchase request only says “concrete expansion joint filler,” ask which material it means. Send the joint width, available depth and location with that question.
Neither supplied sheet gives a backer-rod selection method, sealant bead dimensions or a full-depth filler specification. Don't use this guide to choose a slab joint system or invent a width-to-depth ratio.
Concrete condition changes the sealant choice
Exterior use only. That's Tremco's limit for [Vulkem 116](/vulkem-116/), a textured polyurethane sealant for poured and precast concrete and other construction joints. Don't apply it over damp, green or contaminated surfaces. An occupied building is off limits too, even if everyone leaves while you apply it.
Working with damp or green concrete? [Dymonic 100](/dymonic-100/) is a non-sag polyurethane sealant whose sheet specifically describes adhesion to those surfaces without outgassing. Its listed uses include expansion and control joints and precast concrete panel joints.
Get the joint dimensions before you make the choice. Movement ratings don't tell you the joint size, and each rating belongs to a specific product: Vulkem 116 lists ±25% movement. Dymonic 100 lists ±50% under ASTM C719, plus +100/-50% under a modified ASTM C719 test.
Get the installation detail before opening a cartridge
Measure the joint size and record it along with the concrete condition. Give those details to the specifier or manufacturer, explain whether you're sealing a wall joint, pedestrian area or vehicle route, and say whether you expect water exposure. For that exact application, ask how to prepare the joint, what backing material to use and how to size the bead. Primer needed? Confirm that too, along with when you can put the area back in service.
Don't use Dymonic 100's temperature range to fill in the blank for Vulkem 116. The supplied Vulkem 116 sheet gives no application-temperature range, while the Dymonic 100 sheet lists 4–37°C. Working below 4°C with Dymonic 100? Its sheet directs you to Tremco's cold-temperature application bulletin.
Use each product's own safety data sheet (SDS). For Vulkem 116, that's where you need to get all health and safety information. Check the Dymonic 100 SDS before every use for health hazards and the personal protective equipment you'll need, and keep adequate ventilation while you work.
Avoid an incomplete purchase specification
An expansion-joint use listing alone doesn't settle a particular traffic application. The supplied sheets don't give a traffic-joint installation detail or a reopening deadline. Obtain those instructions before scheduling access.
Planning to paint the bead? Both products can be painted, but you need to check the paint you'll use because Tremco doesn't assure compatibility or adhesion with every paint. Neither product should go in chlorinated, potable, heavy or waste water.
Open the product details, then send Cranco the joint dimensions, substrate condition, exposure and specified material. Ask about the unresolved application details before ordering.