Wasn't sure where to post this question and since I am a homeowner I will start here. I am in the process of designing a pergola for my back patio. We are installing this as the backyard faces the south and we need shade. So my question is this, when installing the rafters on the pergola, which way should they face to get the most protection from the sun? Might sound like a crazy questions, but we are installing this as protection from the sun as our #1 priority. Any thoughts?