December 28, 2014
Grouting flagstone dry
The most important thing to know about grout is that it's mostly for show. It won't hold the flagstone in place if you haven't gotten it laid completely level. So, before you even think about adding grout, be sure that there is no *teeter-totter* effect when you step on the flagstones. The grout won't fix that, all it will do is crack. I generally wait a few days before adding grout, walking carefully on the flagstone, checking for any imbalance. If there is, I pull the flagstone back up, and try again.
One of the worst mistakes I ever made many years ago when I first started adding flagstone to the garden, was to mix up the grout wet, and try to pour it in. What a mess! Then I discovered how to use it dry, this is how:
• Fill a small cup with dry grout and find an old spoon. Be sure to allow a good amount of space along the edge of edge piece of flagstone - grout won't stick to dirt, or mud, it only sticks to the sides of the flagstone. Gently tap the grout into the space between the stones. I use an old toothbrush to gently guide it in.
• Once the grout is in, spray it with a spray bottle. Be gentle. Until the grout has begun to set, it's as light as a feather, and will blow away. I also keep a paper towel, or an old rag, around to immediately wipe any grout that gets on the top of the flagstone. If you don't, and it dries, it will stain, and stay that way forever. Ask me how I know!
By the way, the grout should sit slightly below the level of the flagstone, not be flush with it. That's to reveal the beauty of real flagstone. The grout is a channel for water, so it should sit down about 1/4 inch or more.
I go back for several days and continue to spray the grout with my spray bottle. It's December now, so it's really the best time for this, although I have done it in the summer, and all you have to do is to spray more often, and wear sunblock.
Posted by Brad Hall