Deck Staining Process
 

Currently I have a solid stain on wood deck located in NY, but thinking about switching to a semi-transparent.

What is the process if I do decide to switch to a semi-transparent stain (do I need to power wash and use a cleaner)?

If I decide to use a solid again do I need to power wash and use a cleaner?

Have enclosed some pictures of the deck

http://img.photobucket.com/albums/v2...2/DSC04610.jpg

http://img.photobucket.com/albums/v2...2/DSC04611.jpg

Hit it with a floor sander to remove the solid stain.

Unless all that old solid stain is sanded off to bare wood there's no way for the semi to soak in. It would just float on top of the soild.
Also make sure that mold gets treated to kill it not just washed off.