MAPEI’s BioBlock technology

for mold and mildew resistance

Products identified with MAPEI’s BioBlock logo have been developed in such a way that they do not support mold/mildew/fungi growth after product installation as certified by external laboratories per industry standard ASTM G21: Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi. Common cleaning and maintenance practices are still needed.

ASTM G21 is an industry standard that uses an intensive testing protocol for determining if fungi, including mold and mildew, can grow on a polymeric material. MAPEI uses a third-party lab and the ASTM G21 standard for testing the antifungal effectiveness of MAPEI products containing polymer that incorporate BioBlock technology.

The ASTM G21 test uses a mix of mold and mildew spores commonly found in household environments. Product samples are placed on nutrient-containing plates and sprayed with a mixture of these fungi. For 28 days, the test plates are kept at a constant temperature of 84.2°F (29°C) and exposed to high humidity, which are excellent conditions for fungal growth. The samples are then examined for fungal growth. If no growth is present, the product is considered to not support mold/mildew/fungal growth.

Every MAPEI product identified with the BioBlock logo has passed this rigorous ASTM G21 test procedure, ensuring that the product does not support fungal growth.

Since the introduction of the BioBlock logo in 2003, MAPEI has continued to develop and expand the range and depth of products that include this technology. The list of MAPEI products that carry the BioBlock logo is evolving with the technology and is constantly growing. Look for these innovative products across the following categories: Liquid membranes, adhesives, sealants, caulks, mortars, grouts and finishes. See the product listing below for current BioBlock products.

After installation, MAPEI’s BioBlock products will not support the growth of mold/mildew/fungi – with adequate cleaning and maintenance practices.

MAPEI’s BioBlock products do not support the growth of mold/mildew/fungi – with adequate cleaning and maintenance. Therefore, their use can increase the life of an installation, resulting in fewer callbacks for installers and contractors.

For more information, contact MAPEI’s Technical Services at 1-800-361-9309 (Canada).



The following is a comprehensive, and ever-growing, list of MAPEI’s BioBlock products:



Sealants and Caulks

Mapesil T
Mapesil T
100%-Silicone Sealant for Heavy Traffic and Movement Joints Mapesil T is a professional-grade, 100%-silicone sealant for use on multiple…
Keracaulk U
Keracaulk U
Premium, Sanded and Unsanded Siliconized Acrylic Caulks Keracaulk S (sanded) and Keracaulk U (unsanded) are premium-grade, easy-touse,…
Keracaulk S
Keracaulk S
Premium, Sanded and Unsanded Siliconized Acrylic Caulks Keracaulk S (sanded) and Keracaulk U (unsanded) are premium-grade, easy-to-use,…

Tile/Stone/Grout Problem-Solvers

UltraCare Grout Refresh
UltraCare Grout Refresh
Grout Refresh ™ Universal Grout Colorant and Sealer UltraCare Grout Refresh is a nonflammable, ready-to-use, water-based, polymer-modified…

Waterproofing Membranes

Mapelastic AquaDefense
Mapelastic AquaDefense
Premium Waterproofing and Crack-Isolation Membrane Mapelastic AquaDefense is a premixed, advanced liquid-rubber, extremely quick-drying…
Mapelastic HPG
Mapelastic HPG
Flexible Waterproofing and Crack-Isolation Membrane Mapelastic HPG is a ready-to-use, highly flexible, liquid acrylic waterproofing…

For more information, contact us:

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