my first post, though I've found these forums to be extremely valuable over the past few years as I participated in the building of my house + other projects (so thank you!)
I've just mortared a bunch of natural stone to a small wall behind our woodstove (5' square). The stone is a sandstone-based material that we just went and found in the bush.
Being completely irregular in shape, the stonework has left some biggish gaps, some as big as 2" square. I am looking for the right product to use for grouting. The Mapei Keracolor S grout I have (leftover from tiling project) says it's for up to 5/8" gaps so I'm concerned it will crack in the bigger gaps here. I do not want to use the gray mortar between the rocks (aesthetics)- the rocks are reddish-brown. So I'm looking for brown-tone product.
Any suggestions on what product I should be looking for to do this job right?