Question
QUESTION: I am laying a dry set flagstone walkway at the entrance to my home.  What exactly do I place in the joints?  The joints are about 1".  I have the stones set in a layer of fine gravel/sand.  I noticed you answered another question stating that a cement/dry sand mix should be used.  But is it a good idea to use a cement/dry mix in the joints on a gravel base when i live in the northeast u.s.a. where we have snowy/icy/cold winters?  Won't the walkway begin to heave eventually?

ANSWER: Hi Erik

A dry sand/cement mix is by far the most versatile of all the pointing techniques. However, if your flags are set on a thin or uneven base, it could create problems. A base of 8-10 inches should allow for any 'heaving' and then a dry mix will work fine.2 inches

The base should be a stabilising base of gravel and smaller particles (dust)and not just gravel. If it has to be just gravel, the pieces should be over 2 inches in diameter to ensure a solid base.

Jonathan www.ecologicagardens.com

---------- FOLLOW-UP ----------

QUESTION: Thanks Jonathan, so I would use a gravel/dust base, then a 2" dry sand/cement mix to lay the flagstones in, and then what do I put into the cracks (joints)?  The dry sand/cement mix?  Is that a product like Quikcrete Sand/Topping mix (no. 1103)?  This product has Portland cement in it.  Should I just sweep it into the cracks (joints) and then water it?

Answer
Use a large-gravel base and then lay the flags on a sand/cement mix of around 3:1 and use the same mix for the cracks. Yes, simply brush the mix in and water it lightly (so not to wash it away)

I have no idea what the commercial name for the mix is in the States, as I operate from Italy, but just use a regular builder's sand and a regular builder's cement at a 3 to or 4 to 1 ratio.

Jonathan