How to Prep an Old Deck for New Stain

I'm getting ready to restain our wraparound porch. My first job was to properly prep the surface. I've got three key steps for doing this right, a magic mildew recipe, and a tool that's helping me get the job done as painlessly as possible.
After researching the best way to prepare an old deck for new stain, I came up with three key steps and a video highlighting the process.


Step 1: Pressure wash the area to remove dirt and chipping paint or stain.


Pressure washing quickly removes dirt, loose paint and built-up grime, improving paint adhesion as a result. Use caution when spraying around windows. Also, avoid directing water up under the siding laps, and keep the nozzle at least 12-16 inches from the wood, so it doesn’t splinter it.


Step 2: Scrape and sand off any leftover chipped paint or stain.


Flaking paint must be removed or the new paint on top of it will eventually let go, too. Make sure the surface is dry first. Then with a sharp scraper, follow the grain of the wood with long strokes. Be sure to pound down any nails sticking up and follow that up with a good sanding.


Step 3: Kill any mildew.


A pressure washer and water alone will not kill mildew. Since mildew can bleed through and ruin a new coat of paint or stain, it needs to be dealt with. I used the homemade mildew wash recipe below coupled with the HomeRight® Deck Washer Flow-Through Broom to tackle our porch mildew quickly and easily.
Homemade Magic Mildew Wash


1 gallon water


1 quart laundry bleach


1 pint rubbing alcohol


2 Tablespoons Murphy’s Oil Soap (or other non-ammonia detergent)


After mixing this concoction up, I used the deck washer broom to brush it on. (Remember to mix this solution outside or in a very well-ventilated room). Then I attached a garden hose to the broom and turned it on. The broom’s stiff bristles loosened and pushed the debris, while the water jets blasted the area clean.


After these three steps, be sure to let the surface dry really well. Then you are ready to apply that beautiful new coat of paint or stain! I’ll be changing the color of our porch floor and using solid color stain. So stay tuned for that project coming soon.
Living Rich on Less - Susan
Want more details about this and other DIY projects? Check out my blog post!
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  • Joan Joan on May 19, 2017

    I don't have mildew but I do have some green algae. Any suggestions for removing it? Thanks.

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