I am planning to make a concrete floor and build a sixteen by twenty foot shed on it with eight foot high walls. The roof will have a 4"/12" pitch. I would like info on the thickness of the slab I should use as well as how much mesh or steel rod I should put in. I am really new to this, so I am looking for detailed ... very detailed information. I should also mention that I live in Canada where the weather varies a lot. In the summer, the thermometer reaches around 30 degrees celsius, and in the winter, the temperature can go as low as the minus 30's.