We have a 12 year-old wood frame house with pine log slab siding. It has been cleaned and treated twice with CWF-UV Clear Wood Finish. We are not impressed with CWF. Some sun-deprived areas have turned black. I suspect mold but one painting contractor believes its Tannin leaching from the log siding. Your thoughts? Should we wash with TSP/bleach mixture or corn-cob blast? What can we treat siding with to prevent mold re-forming? We like a clean, natural look.

waterloop Changed status to publish April 3, 2024