Hello. I have a three season porch that originally just had screens but now we have windows installed so all rain and snow won't come in. The problem is I get a little bit of rain seepage under the walls. We didn't plan on waterproofing the porch from the beginning so my knee walls are just azek type material over the floor boards. What's the best way to stop wet seepage before I have an indoor/outdoor carpet laid down? Just caulk it or use some type of flashing on the outside? Not sure how or what to do. Any suggestions would be great - the easier the better, I'm an accountant and not that handy. Thanks in advance! I'm attaching a pic if that helps.

Bob