Final Update! I am so excited and pleased to note we no longer have a flooded patio. All that hard work has paid off. We finally got some rain that started at about 4 am yesterday and it's still raining. There has been some extreme heavy downpours throughout it. We have zero standing water on our patio, except that far corner but it drains off quickly and it is a problem because they didn't lay the concrete with drainage in mind. It is just flat without thought to drain the water away. We are very pleased and now I am not worrying about my house flooding when heavy rains come. It is very much a relief to my psyche.