Stubborn Exterior Mildew

This is a photo of mildew on the underside of a porch ceiling stained with Rubio Hybrid Wood Protector with extra M1 Mildewcide added: https://imgur.com/a/lbMsHS1. The substrate is Doug Fir,… This is a photo of mildew on the underside of a porch ceiling stained with Rubio Hybrid Wood Protector with extra M1 Mildewcide added: https://imgur.com/a/lbMsHS1. The substrate is Doug Fir,…Read MoreGreenBuildingAdvisor