Most people understand that waterproofing masonry is a good idea. The video above is quite amateurish (I shot it from my phone, narrated it on the fly, and it has some choppy splicing…), but is fundamentally educational.

     Any masonry that can be penetrated by water can be affected by freezing temperatures. Rocks are broken down by moss, lichen, and frost wedging. This happens to masonry as well. As a matter of fact, the reason that you are able to eat a salad is that rocks were broken down into soil because of frost wedging (and other factors) breaking down rocks.