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.
SURFACE PREPARATION
• Surfaces must be structurally sound, stable, clean and free from dust, oil,
grease, paint, gypsum patch, flooring adhesive, tar, wax, sealers, curing
Premium, Sanded and
Unsanded Siliconized
Acrylic Caulks
Ke
racaul
k
®
S
/
Keracaulk
U
Ke
racaul
k
®
S
/
Keracaulk U
Version: Sept. 15, 2017