What should I do when grouting very porous or rough textured stone (e.g. travertine)?
The use of a high quality grout release or grout sealer is recommended. The use of these types of product will aid in the clean-up process and help prevent the tile or stone from being stained, or having the voids filled by the grout in such a way that cleaning would be very difficult. Contact the manufacturer of the grout release or sealer product for their recommendation and conduct a test area to determine suitability and acceptability.