How do we fix a worn and weathered deck?
Our inspector said our deck was weathered and worn. What needs to be done to it and what time of year is best to do the work - spring or fall?
Either the spring or fall are good times to do deck work. I would start by scrubbing the deck with a solution of detergent, water and bleach (20 to 25% bleach). Once cleaned up, I would replace any badly deteriorated boards. Boards which show significant surface deterioration, but are still structurally sound can be flipped over as opposed to being replaced.
While usually not necessary, cedar or redwood decks can be power sanded, but because they are softwood, this requires a certain level of skill. It is also absolutely necessary to ensure that every nailhead or screw on the deck is countersunk so that it does not tear up the sandpaper or the machine. Pressure treated decks cannot be sanded, because the chemicals don't penetrate the wood very far. After cleaning and fixing, seal the deck with a wood preservative. There are many sealers out there designed for wood and concrete and masonry. Don't use these. Use sealers designed for wood only, that contain UV protection and a fungicide to prevent the growth of moss. Reseal the deck annually.
