Q: How do I know which type of cleaner to use for my wood before applying a clear waterproofer or exterior stain?

It’s important to choose the right cleaner for your project to ensure the best adhesion during the waterproofing / staining process. Use the below guide as a reference when selecting a surface cleaning product.

For Exterior Wood Surfaces:
If you need to remove: Use:
Weathered clear waterproofers & transparent or semi-transparent stains in addition to stains from dirt, mildew, algae & fungus Thompson's® Water Seal® Heavy Duty Deck Cleaner
Oil & water-based solid stains and long-lasting, hard-to-remove semi-transparent stains & waterproofers in addition to stains from dirt, mildew, algae & fungus Thompson's® Water Seal® Maximum Strength Deck Stripper
On REDWOOD/ CEDAR/ HIGH EXTRACTIVE Wood: Tannin staining and restore lighter color of redwood, cedar, mahogany or other highly extractive wood species in addition to removing stains from dirt, mildew, algae & fungus and/or, as instructed to neutralize any wood species after using other cleaners
Thompson's® Water Seal® 3 in 1™Wood Cleaner
For Exterior Multi-Surfaces:
If you need to remove: Use:
On exterior surfaces such as wood & composite decks, fences, concrete & masonry, outdoor furniture, roofs & siding: Stains from dirt, mildew, algae & fungus with a non-bleach, chlorine-free oxygenated foaming formula Thompson’s® WaterSeal® Oxy Foaming Action Exterior Multi-Surface Cleaner

Q: How important is it to properly clean my deck before applying a clear waterproofer or exterior stain?

Proper surface preparation is necessary for the best waterproofing / staining application and performance. All exterior wood – from decks to fences to siding – should be cleaned before sealing, staining or painting to remove waterproofers, wood stains, or stains from dirt, mildew, or algae. Even new wood can have dirt or other invisible barriers to the penetration of a coating. For instance, new wood can have invisible mill glaze, caused when the heat of the milling equipment reacts with the natural oils in the wood, that needs to be removed.

Q: What is the best way to apply Thompson’s® WaterSeal® cleaners?

The fastest way to apply is with a pump-up sprayer (using a coarse setting), but you can also apply with a brush or a roller. You should apply liberally. In the case of areas with heavy discoloration or dirt, apply a second coat, brush lightly with a broom and hose off.

Q: How long after cleaning can I apply waterproofers or stains?

Weather and environment can create various factors. Always follow the instructions on the waterproofer or exterior stain product label.