I'm not familiar with wood guard but I have used sikkens log and siding on cedar log homes and it is a great$$$$ product. I am assuming it is a re-stain. Power-wash and scrub surfaces with bleach-water/TSP solution. Power wash all solution off. I use a 2 coat system with Sikkens but you should check the can to see if this works well with wood guard. Remember the ***** can be time consuming to keep it clean!