How to Guide
DESCRIPTION
Keracaulk S (sanded) and Keracaulk U (unsanded) are premium-grade, easy-to-
use, easy-to-clean siliconized acrylic caulks formulated to match all of MAPEI's
grout colors.
FEATURES AND BENEFITS
• Water cleanup while fresh
• Paintable
• BioBlock
®
technology for mold and mildew resistance
• Packaged in gun-grade tubes for easy application
• VOC-compliant
INDUSTRY STANDARDS AND APPROVALS
• ASTM: Meets C834 for low-movement sealant
LEED v3 Points Contribution LEED Points
MR Credit 5, Regional Materials* .......................................Up to 2 points
IEQ Credit 4.1, Low-Emitting Materials –
Adhesives & Sealants ..................................................................1 point
IEQ Credit 4.3, Low-Emitting Materials – Flooring Systems .............1 point
* Using this product may help contribute to LEED certification of projects in the
categories shown above. Points are awarded based on contributions of all
project materials.
WHERE TO USE
• For gaps up to 1/4" (6 mm)
• As a flexible barrier/filler between horizontal and vertical surfaces to prevent
cracked tile due to expansion
• For filling joints where tile abuts dissimilar surfaces
• For caulking around sinks, tubs, showers, countertops and ceramic tile floors
• For interior use only
• For restoring cracked or worn grout joints
LIMITATIONS
• Do not install over substrates containing asbestos.
• The application temperature range is 50°F to 90°F (10°C to 32°C).
• Apply only to clean, dry surfaces.
• For both Keracaulk S and Keracaulk U, joints should not exceed 1/4" (6 mm)
in width.
• Do not use for exterior projects or applications subject to constant water
immersion.
• Do not use in areas where joints will be subject to heavy abrasion or wear.
• Allow new concrete to cure for 30 days before caulking.
• Although Keracaulk S and Keracaulk U are color-matched to MAPEI’s
grouts, expect a slight variation in color due to the difference in composition
between materials.
• For applications beyond 1/4" (6 mm) in depth, the caulking depth must
be controlled by a closed-cell backer rod.
• To ensure product effectiveness, do not apply Keracaulk S or Keracaulk U
thinly, as with a paint.
• Keracaulk S and Keracaulk U may stain porous materials. Test on a separate
area before final application.
• Refer to the project's ASTM requirements before commercial use of
Keracaulk S and Keracaulk U.
Premium, Sanded and
Unsanded Siliconized
Acrylic Caulks
Ke
racaul
k
®
S
/
Keracaulk
U
Ke
racaul
k
®
S
/
Keracaulk U
Version: June 2, 2016