Are these two the same product?

Yes. Both are Schluter Kerdi-Fix, a 9.81 fl oz cartridge of silane-modified polymer sealant. The difference is color: A is gray, B is white.

Which color should I buy?

Match the membrane and grout. Gray hides seams on Kerdi-Board and gray membrane. White suits white tile, white trays and light grout lines.

Is Kerdi-Fix worth $29.74?

It is the sealant Schluter specifies for Kerdi seams and penetrations, and one cartridge covers a typical shower's corners and pipe collars. Reviewers call it strong but some call it overpriced.

Does Kerdi-Fix prevent mold in a shower?

It is waterproof and mold-resistant itself, but one reviewer reported mold around a shower base within about six months. That usually points to trapped moisture behind the seal, not the sealant failing.

Can I use it outdoors or on metal?

Yes. Both versions are UV- and weather-resistant and rated for outdoor use and for metal, glass, stone and tile.

How much does one cartridge cover?

At 9.81 fl oz, plan on one cartridge for seams, corners and pipe penetrations in a standard shower. Buy a second for full Kerdi-Band runs or a bench.

Schluter Kerdi Fix vs Schluter-Systems Kerdi-Fix White Joint sealer

These are the same product: Schluter Kerdi-Fix, a 9.81 fl oz cartridge of silane-modified polymer sealant and adhesive for Kerdi membrane, Kerdi-Board, tile, metal, glass and stone. The only real difference is color and stock: Product A is the gray version, Product B is listed as white. Both are $29.74 at The Home Depot as of November 4, 2026, but A is carried by 7 stores and B by 4. Buy the color that matches your grout or trim, and check the store count if you need it fast.

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