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Community and Q&A

Masonry cement odor

John Bertelsen | Posted in General Questions on

We installed a Boral synthetic stone surround using Tolteca type s masonry cement at an interior wall fireplace renovation. After 6 months there is still an odor coming from the surround. That wet mud, almost gym sock smell that varies in intensity with weather changes. Boral says it cannot be the stone and the mason says he has no history or reports of this odor. We have had environmental testing for VOC, MVOC, swab, and mold. No issues, but smell was corroborated by them.
What can we do except rip it out?

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  1. Terry Lee | | #1

    Tolteca type s masonry cement: This masonry cement is junk! The clinker and calcium carbonate is not pure lime, along with the gypsum filler they used to get their manufacturing cost down.

    Look around for efflorescence heat-moisture-acid rain getting into a bad detail can grow, that when heated can cause a bad odor....see if the smell is coming from the mortar, the stones look good quality. Look for mold, mildew, and fungi too.

  2. GBA Editor
    Martin Holladay | | #2

    Is this fireplace surround getting hot when the fireplace is operating? If so, is the odor associated with the times that the fireplace is operating -- or do you notice the odor at all times?

    You note that the smell "varies in intensity with weather changes." Does that mean that it smells more during humid weather than during dry weather?

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