MINIMIZE MOISTURE 

For mold and mildew no meal is complete without a beverage. Take away their water and these two wood threats will move on to greener pastures. Make a thorough survey of possible moisture sources and stop mold and mildew before they start. If the stain has lost its water-repellent properties, it may be time for a new coat. For a high level of protection against moisture and mildew, consider using a product like Cabot® Solid Color Acrylic Stain + Sealer. 

RE-ROUTE WATER AWAY FROM YOUR HOME 

Make sure your roof has an effective gutter system and that your surrounding property has sufficient drainage. Remove snow off of flat surfaces, including roofs and decks, and periodically check the flashing and caulking around doors and windows.  

REMOVE SNOW OFF YOUR DECK 

As snow thaws and re-freezes it seeps into the wood and could cause cracking.  Rather than using a shovel, consider using a stiff bristle push broom or leaf blower to help protect the integrity of the coating.