I have an older clay tile roof and I have a handful of missing and/or broken tiles that I'm going to replace. I understand that the ridge tiles should be set in mortar and pointed around the edges with it. I can find a few different brands of roof tile mortar....quikrete and then some other brand on HD website but neither of them seem to be available in my area (which makes sense as there aren't a lot of clay tile roofs in Central Illinois) and there's not even an option to have it shipped (which would be expensive anyway, I'm sure). So, anyone have any advice where I can get roof tile mortar in central IL OR how I can make it myself?

Thanks!