Q: When building tall walls of stone for a house, (two story), besides having a good SOLID foundation on which to build on, what kind of mortar/cement do you use for such a structure and how do you mix it, (ratio of sand to cement), do you use lime also? This home will be located in Woodstock, VA. and they have a very humid climate in the summer time and it can get very cold in the winter months, but not for extended lengths of time. Please be very specific, as I have read different things about mixing the components and am a little confused about mortar and cement. Are there certain brands that are better than others......are there some to stay completely away from?

A: Use a type S masonry cement mixed with three parts clean sand. I have heard of people using a type N masonry with a shovel of portland for every two of masonry. The type S gives a more structural capability necessary for a tall wall. The N is more flexible and appropriate for a veneer or brick work. Try a small project first and the rock will teach you more than I can with these few notes.

Q: I am putting flagstone on my foundation. What do you use? Mason S? And how do you use Mason S? And how do you get them to stick on the wall? It is between 3/4 to 1 1/2 inch thick.

A: The type N masonry might be better served for your purpose. It is a little more flexible and you won't need the structural capabilities of the S. I would try and stick right to the concrete foundation with a little masonry glue in the mortar and paint some on the wall too. You shouldn't need an expanded metal lath if the wall isn't too high.

Q: I'm wanting to cover a cement block wall with stacked flagstone to give it the look as if it were made of flagstone. I would like it to be held together with mortar, but I don't want to see the mortar, I would like it to look dry stacked. The wall is only about 30 inches tall. I've already attached aluminum straps to the block wall to help hold the flagstone in place, but I'm not sure exactly where to go from her. I want to make sure the mortar I bought is the right type (Portland mortar). I also like to make sure my mix is right. I was planning on a 3 sand to 1 mortar mix. Is there anything else that is important to this type of wall or is there a better way I should be going?

A: Portland cement is not the way to go for such an application. You will need a masonry cement, type N for this particular application. A 3 to 1 mix is appropriate. If you can't find the masonry cement or feel that you must go with the portland it can be mixed with lime to give it the flexibility that is needed. I would try a test mix to get the best results but 2 Portland,1 lime, 9 sand is a good starting point.