We live in Louisiana and have a back porch with stained cypress tongue and groove beaded board ceiling and 12x12 solid cypress stained columns. The house was built 2 yrs ago. I'm not sure if the painter treated it correctly but the posts mildewed so badly on some sides that you couldn't even see the wood grain anymore. The ceiling is starting to turn black as well in some areas. What is the best solution or product/method to remove the mildew and prep it. I plan on using a semi-transparent stain/sealer from Sherwin Williams to re-treat the posts after they are clean. Also, for cleaning the rest of the house, what product/solution do you recommend for painted surfaces. Thanks in advance.