I've mentioned in other areas I'm really wanting to get into other areas of landscaping. So last week when my dad told me he was laying down a patio in back with a firepit in the middle I was a little upset that I wouldn't have time to be there working on it, perfect place to practice and learn. Went over this morning and they are at the point of laying stone, its in a 6'x6' pattern. When we got to the edge of laying out the first side there is about a 2inch gap or more. We measured out the other side going out and the same thing would happen there too. What did they do wrong that made the gaps on each side. Patio is 16'2''X16'2" you can see the gap in the pic.