NASCLA Accredited Commercial General ContractorFinishesMedium

A contractor is installing ceramic tile in a high-traffic commercial restroom. To ensure the grout resists staining, mildew, and chemical degradation, which type of grout is most appropriate?

  1. ASanded cementitious grout
  2. BUnsanded cementitious grout
  3. CEpoxy grout
  4. DAcrylic latex modifying grout
Show answer & explanation

Correct answer: C. Epoxy grout

Epoxy grout offers superior resistance to staining, mildew, chemicals, and abrasion compared to cementitious grouts. Its non-porous nature makes it ideal for demanding environments like commercial restrooms where hygiene and durability are critical.

Why the other options are wrong

  • A. Sanded cementitious grout is more durable than unsanded but still porous and requires sealing, and its chemical resistance is limited.
  • B. Unsanded cementitious grout is porous and prone to staining and mildew, requiring sealing, and lacks chemical resistance.
  • D. Acrylic latex modifying grout improves the performance of cementitious grout but does not offer the same level of stain and chemical resistance as epoxy grout.

Epoxy Grout

A two-part grout system (resin and hardener) that forms a dense, non-porous, and highly durable joint, offering excellent resistance to stains, chemicals, and mildew.

  • Two-part system
  • Non-porous
  • High chemical/stain resistance

Memory trick: For 'commercial restrooms' and 'super durability', 'Epoxy' grout is the 'clean' choice.

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