TEC (H.B. Fuller)

Fast Set Mortar (395)

Powder · US · manufacturer-sourced

Check your container: This countdown is for the Powder variant. Similar-looking versions may have different times.

How long before you can grout over TEC (H.B. Fuller) Fast Set Mortar (395)?

Short answer

Ready for grout: 150 minutes to 3 hours after application.
Full cure: 21 days after application.
Grout & tile mortar

Grout wait-and-wash

Wipe-off, light foot traffic and sealing each have their own wait

  1. Pack the joints with Powder
  2. Wipe off inside the stated window
  3. Seal and use only after the stated cure

This product’s stated stages

  • Working time ends20–30 minutes
  • Ready for grout2 hours 30 min to 3 hours
  • Full cure3 weeks

Worth noticing: Working time is only 20–30 minutes; the next stated stage, ready for grout, is 2 hours 30 min to 3 hours.

Common mistake: Sealing or soaking a grout joint that has set but not fully dried.

Grout & tile mortar

Return-to-use gates

Open the surface gradually instead of treating cure as one moment

Touch / inspectA surface check only
Foot trafficUse the stated walking time
Heavy useWait for furniture, water or vehicle readiness

Time the grout cure

When was the grout applied?
Conditions that affect drying
Where?
Thickness

Stated times

  • Working time ends20–30 minutes
  • Ready for grout150 minutes to 3 hours
  • Full cure21 days

From TEC (H.B. Fuller) data sheet · checked 2026-10-25. Anything not listed isn’t stated by the manufacturer.

Manufacturer website: tecspecialty.com

Conditions & fine print
  • Stated conditions: Not stated in the data sheet
  • Times depend on temperature, humidity, substrate and tile type. Follow the current data sheet for your exact setting bed and application. Do not apply when the area and substrate are below 50°F (10°C).
  • Apply at 50°F or above
  • Region US. Formulas can differ between countries; check your container.
  • Working time ends: Room temperature.
  • Ready for grout: The source gives no conditions for this time.
  • Full cure: The source gives no conditions for this time.
  • 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 Report outdated information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
TEC (H.B. Fuller) Fast Set Mortar (395)
Variant
Powder
Region
US
Listed use
tile mortar, thin set, fast tile
Timed stages recorded
tooling, grout ready, full cure
Source checked
2026-10-25

Documentation: Technical data sheet · DSFSM R0925-20

Condition attached to the stated time: Room temperature.

About this product

Fast Set Mortar (395) is a grout & tile mortar product from TEC (H.B. Fuller), listed for tile mortar, thin set, fast tile. Its times are stated under: Room temperature. The source gives a range for grout: 150 minutes to 3 hours.

Using this specific product

TEC (H.B. Fuller) Fast Set Mortar (395) is listed here as the Powder version for tile mortar, thin set, and fast tile. For grouting tile, 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 Powder; related versions can use different timing.
  • For tile mortar, thin set, and fast tile, pay particular attention to joint depth, water ratio, cleanup and room conditions.
  • Room temperature. The source gives no conditions for this time.

How to check readiness

Inspect shaded joints and verify the stated water or traffic milestone. Open time at room temperature is 20 to 30 minutes (pot life 50 minutes). Grouting can begin typically 2.5 to 3 hours after installation is completed. Reserve full cure for demanding use, chemicals, washing, immersion or load—not merely gentle handling.

Avoid this mistake

Color change alone does not prove the joint is ready for immersion.

Compare with similar products

Keep going

Questions

How long before you can grout over this product?

TEC (H.B. Fuller) states: Open time at room temperature is 20 to 30 minutes (pot life 50 minutes). Conditions: Room temperature.. Grouting can begin typically 2.5 to 3 hours after installation is completed. Conditions: The source gives no conditions for this time.. Final cure is 21 days. Conditions: The source gives no conditions for this time.. These are the manufacturer’s stated times, not a guarantee.

How does Fast Set Mortar (395) compare with other grout & tile mortar products?

TEC (H.B. Fuller) states 150 minutes for grout, which is quicker than the typical grout & tile mortar product here (median 16 hours across 17 products). The quickest listed is Custom Building Products Aqua Mix Pro-Solv Sealer at 2 hours; the slowest is MAPEI Kerabond T / Keralastic System at 1 day.

What conditions do the stated times for Fast Set Mortar (395) assume?

Stated conditions: Room temperature; The source gives no conditions for this time. Application temperature: 50°F or higher. Cooler, damper or thicker applications usually take longer.

Why does Fast Set Mortar (395) show a range for working time?

The source gives 20–30 minutes for working time. This site counts down to the earliest stated time (20 minutes) and keeps the range visible so you can judge the rest from your conditions.

How long does this product take to fully cure?

TEC (H.B. Fuller) states: Final cure is 21 days. Conditions: The source gives no conditions for this time.. These are the manufacturer’s stated times, not a guarantee.

How long do I have to work with this product?

TEC (H.B. Fuller) states: Open time at room temperature is 20 to 30 minutes (pot life 50 minutes). Conditions: Room temperature.. These are the manufacturer’s stated times, not a guarantee.

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

Times depend on temperature, humidity, substrate and tile type. Follow the current data sheet for your exact setting bed and application. Do not apply when the area and substrate are below 50°F (10°C). Follow the product label for your conditions.

Similar products

All grout and tile mortar