Tremco

Vulkem 445SSL

Semi-self-leveling polyurethane sealant · US · manufacturer-sourced

Check your container: This countdown is for the Semi-self-leveling polyurethane sealant variant. Similar-looking versions may have different times.

How long does Tremco Vulkem 445SSL take to dry?

Short answer

Tack-free: 5 hours after application.
Caulk & sealant

Bead cure stages

Skin, tack-free and paint-ready are not the same moment

  1. Gun a continuous bead of Semi-self-leveling polyurethane sealant
  2. Tool it inside the working time
  3. Keep it dry until the stated water-ready time

This product’s stated stages Quoted at 73°F and 50% humidity

  • Working time ends1 hour 30 min to 2 hours
  • Tack-free5 hours

Worth noticing: Working time is only 1 hour 30 min to 2 hours; the next stated stage, tack-free, is 5 hours.

Common mistake: Showering or painting at skin-over, when the bead is only crusted on the outside.

Caulk & sealant

Bond-strength path

Assembly, handling and full load are different stages

1 · AssembleClean, fit and apply the Semi-self-leveling polyurethane sealant version correctly.
2 · HoldKeep the joint undisturbed through its set or clamp stage.
3 · LoadUse full cure—not surface firmness—before demanding use.

Time the caulk cure

When did you run the bead?
Conditions that affect drying
Where?
Thickness

Stated times

  • Working time ends90 minutes to 2 hours
  • Tack-free5 hours

From Tremco data sheet · checked 2026-10-25. Anything not listed isn’t stated by the manufacturer.

Manufacturer website: tremcosealants.com

Conditions & fine print
  • Stated conditions: 73°F (23°C) and 50% relative humidity
  • Sealant skin and tack-free times are for a thin film. Deep joints cure from the outside in and take longer. Follow the current data sheet.
  • Apply at 40°F or above
  • Region US. Formulas can differ between countries; check your container.
  • Working time ends: By ASTM C679.
  • Tack-free: At 23°C (73°F) and 50% relative humidity.
  • Entered from the cited manufacturer documentation. Check the current label for the exact formula and region. Report outdated information
  • Actual results depend on preparation, thickness, ventilation, temperature, humidity, mixing and substrate.

Confirm this is your product

Closely named formulas, colors and regional versions can use different times. Match these details to your container before starting a countdown.

Exact listing
Tremco Vulkem 445SSL
Variant
Semi-self-leveling polyurethane sealant
Region
US
Listed use
horizontal joints
Timed stages recorded
tooling, tack free
Source checked
2026-10-25

Documentation: Technical data sheet · Document 0118/V445SSLDS-ST

Condition attached to the stated time: By ASTM C679.

About this product

A semi-self-leveling urethane whose cure is given as a rate, about 1/16 inch of depth per day, plus one extra day for every 10°F drop. That makes the cure time of a deep joint something you calculate rather than read off a chart.

Using this specific product

Tremco Vulkem 445SSL is listed here as the Semi-self-leveling polyurethane sealant version for horizontal joints. For sealing a joint, the useful question is not simply whether the surface looks finished—it is whether the exact next-action milestone shown above has been reached.

Before you start

  • Confirm the package says Semi-self-leveling polyurethane sealant; related versions can use different timing.
  • For horizontal joints, pay particular attention to joint depth, tooling, ventilation and exposure to water.
  • By ASTM C679. At 23°C (73°F) and 50% relative humidity.

How to check readiness

Probe an inconspicuous edge for a continuous skin and follow the stated water-exposure milestone. The data sheet gives a skin time of 1.5 to 2 hours. The data sheet gives a tack-free time of under 5 hours.

Avoid this mistake

Surface skin is not the same as through-cure, especially in a deep joint.

Compare with similar products

Keep going

Questions

How long does this product take to dry?

Tremco states: The data sheet gives a skin time of 1.5 to 2 hours. Conditions: By ASTM C679.. The data sheet gives a tack-free time of under 5 hours. Conditions: At 23°C (73°F) and 50% relative humidity.. These are the manufacturer’s stated times, not a guarantee.

How long will a half-inch joint of Vulkem 445SSL take to cure?

The sheet gives a cure rate of approximately 1/16 inch per day, so a half-inch depth is roughly 8 days at normal conditions, plus about a day for each 10°F below normal.

How long do I have to work with this product?

Tremco states: The data sheet gives a skin time of 1.5 to 2 hours. Conditions: By ASTM C679.. These are the manufacturer’s stated times, not a guarantee.

What affects how long this product takes to dry or cure?

Sealant skin and tack-free times are for a thin film. Deep joints cure from the outside in and take longer. Follow the current data sheet. Follow the product label for your conditions.

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