We have a one-year old timberframe house in middle Maine. The porch timbers (white oak) have quite a bit of mildew. It was a long winter with a lot of snow and then a rainy spring. The wind blows from the west and north so that the front porch faces east and thus, the airflow is minimal. The timbers have only the original coat of oil. My builder has offered to sand the timbers but is not sure whether to use a bleach and in what proportions. Also, what would be the best suggestion for an oil sealer? I noted in another blog the recommendation to use a marine grade sealer.
Appreciate the assistance.