Correct mortar mix to build stone wall

Stone is best with lime, for several reasons, the first of which is that lime is softer than stone and will accommodate the natural expansion and contraction of the wall with heat and cold without the risk of the stone degrading or cracking. Secondly, aesthetically, lime looks better than cement. Adding building lime to cement does not give you lime mortar, it just provides better workability and a slower set. You still end up with cement. I always use sharp sand for wall construction, it sets much faster and holds the stone in place better. You don't mention what type of stone it is. If it's something like limestone, you should use NHL 3.5, unless it is very crumbly, in which case NHL 2 would be better. For harder stone, I tend to use NHL 5 as it weathers better. The lime mortar should always be softer than the stone. It is more expensive than using Portland cement, but if you have taken the time to use lime with the house, it would be a shame not to have a matching wall. Lime is also a natural fungicide, so the wall will remain looking better for longer. Hope this helps. Kevin Limeclad.

great answer

i would use a 5 sand 1 cement and 1 lime. using less cement will not save you much money and will weaken the mix i would always have a ratio of no less then 1 part cement