Grouting mortar

Ready mixed grouting products are available from builder’s merchants including Sika, Lafarge, and Weber & Broutin.

• they do not shrink or crack when drying,
• they often contain additives that improve waterproofing and delay the setting time thus improving their performance,
• If adding colouring agents, do a trial on a dry piece of stone to check the result.  
• One can prepare one’s own mixture with fine sand and a binding material (white lime or white cement).   Do not use grey cement.   Too strong a cement mix will block evaporation through the joints.