How to Clean and Seal Deck Surfaces 

Welcome to the H.R.C. clinic on cleaning and sealing your deck. Wood doesn’t last forever, but its life can be
extended considerably with a little help and know how on your part. There’s something for almost any deck owner here, so please read the following information on caring for your deck. 

Outdoor Preservation
On the Surface: A Complete Look
The First Year - Getting Off to a Good Start
How to Apply a New Wood Treatment
Your Deck is Gray, the Sky is Blue - Get Busy
If the Deck is Stubborn, You Can Be, Too
Sunscreen for Your Deck? Hey, It Ages, Too

Outdoor Preservation
The deck is a valuable asset to your home. It’s surface is constantly exposed to the elements causing the wood to crack, fade, split, cup and warp. There are a number of products available today to help protect and prolong the life of your investment. Although pressure-treated wood resists insects and decay, it’s still vulnerable to moisture and the sun’s rays. The same applies to other exterior woods including cedar and redwood. To keep it looking new and lasting longer, a regular maintenance treatment system is necessary. 

On the Surface: A Complete Look 
Each wood care product has a specific benefit for all wood surfaces, giving you the ability to customize a complete wood care system. This system begins the very first day and continues throughout the life of your wood. Here are some products you might consider. 

New Wood Treatment: Protects brand new wood from the ravages of sun and rain.

Deck Cleaner and Brightener: Puts new life into dirty and graying decks.

Stain/Finish Remover: More powerful than a wood cleaner, this actually gets under and lifts off old sealers, finishes, and dirt that have built up on your deck over time.

Clear Wood Preservative with UV Protection: Revives the beauty of your weathered deck while protecting against the elements with a clear finish.

Exterior Stain: Solid or semi-transparent. Deep penetrating formula repels water. These are available as water-based or oil-based products; both provide fade and mildew resistance. 

The First Year (Getting Off to a Good Start) 
It’s very important for all wood, whether it’s pressure-treated pine, cedar or redwood, to weather properly before applying a penetrating oil finish. During the critical first year, excess water must evaporate from the wood, and the mill glaze must wear off of smooth wood, allowing the wood fibers to open up. Only after this happens is the wood porous enough to accept a penetrating finishing coat. 
It’s very essential to apply a new wood treatment initially. An immediate application provides a slow, steady, weathering period. The movement of moisture into and out of the wood is controlled. This treatment also keeps the wood’s natural color looking new longer. 

How to Apply a New Wood Treatment 
Read the manufacturer’s instructions on the label before beginning. Make sure the weather is not going to turn cold or wet within the next 24 hours following application. Do not apply in direct sunlight. Give it a day to dry. 

1.Remove all loose debris and dirt from the wood you are treating. 

2.Cover adjacent areas such as plants and bushes with a tarp or drop cloth. 

3.Apply a liberal coat with a brush, roller or garden sprayer. Be sure a sufficient amount of the treatment flows between the boards and into cracks. Saturate the end grain also. 

4.Wash off tools, equipment and tarp with appropriate solution (usually soap and water). 

5.Now sit back and let the wood weather for about 12 months before staining or finishing with a penetrating oil. 

Your Deck is Gray, the Sky is Blue! Get Busy
An old, dirty, gray deck could use a facelift. Deck cleaners come in bleach and non-bleach based. With either type, you can remove surface and ground in dirt even nail stains. Bleach based cleaners lighten the wood, whereas non-bleach based gently remove the dirt and nail stains without any damage to the wood fibers or the wood’s natural color, while being very environmentally friendly to surrounding plants and shrubs. 

How to Apply a Deck Cleaner
Carefully read the manufacturer’s label. Allow the deck 2 days drying time after cleaning before sealing. Sunshine and a slight wind speed the drying
process. 

1.Before using the deck cleaner, sweep away all loose debris. 

2.Wet the surface and any surrounding plants and shrubs with a garden hose. Mix the appropriate amount of cleaner with water. If the wood is extremely dirty, use less water, especially for decks that haven’t been cleaned in the last couple of years or more. 

3.Apply the cleaner with a roller, sprayer or stiff bristle brush (acid wash brush). (Use a long handle with the brush to save your back.) Tough areas will definitely need to be scrubbed thoroughly with a brush. If you are hand brushing, remember to wear gloves. 

4.For the cleaner to work its best, keep the deck wet while applying it. Allow the appropriate time lapse for the cleaner to work (about 20 minutes; longer for extreme dirt). This gives the detergents time to remove the ground-in dirt and brighten the wood. 

5.After you allow the cleaner to do its work, rinse with a garden hose. 

If the Deck is Stubborn, You Can Be, Too 
That hazy, weather-worn look your deck develops over the years comes from old finishes, sealers and dirt. Use a good stain and finish remover that is especially designed to go a step further than cleaning. As a result, you’ll get a clean, sound surface just waiting to be refinished. Some solutions are rather harsh and hard to work with, so read the label before choosing one right for you. 

How to Apply a Stain/Finish Remover 
Carefully read the manufacturer’s label. Always wear eye and skin protection. Use as is, do not dilute. 

1.Begin by covering areas you are not cleaning with a drop cloth or tarp. Wet the surrounding plants and shrubs. 

2.Apply a uniform coat of remover to the deck’s surface, keeping the area wet with the solution for at least 10 minutes. (Stubborn finishes may take longer.) 

3.When the finish and dirt begin to lift from the wood, scrub with a stiff bristle brush (acid wash brush works fine). Do not use a wire brush. 

4.Repeat the process if necessary on the more stubborn areas. 

5.Wash tools and drop cloths/tarps with soap and water. 

6.Allow your deck to dry a minimum of 2 days before refinishing. 

Sunscreen for Your Deck? Hey, It Ages, Too 
Wood finishes containing a "sunscreen" are available to protect your deck from harmful U.V. rays which fade and prematurely age the wood. If your deck looks like it’s made out of driftwood, it desperately needs a good wood finish! Unlike a surface sealer, the oils found in a wood finish actually penetrate deep into the grain, renewing the overall look while protecting it against moisture damage. 

How to Apply a Wood Finish
Use a wood finish only on wood that has weathered for a year. Before applying, make sure the wood is thoroughly cleaned (as described above). Carefully read the manufacturer’s instructions. Always wear eye and skin protection. 

1.Cover all surrounding surfaces with a drop cloth or tarp. 

2.Apply the wood finish using an airless sprayer, brush or roller. Let the finish penetrate and soak in for 20 minutes. 

3.Backbrush (go back over the surface with a brush) for uniform coverage and penetration. 

4.Brush out any puddles to avoid shiny patches. For extra protection, apply a second coat. 

5.Allow to dry for 1 to 2 days. 

6.Wash all tools, equipment and tarp with soapy water. Dispose of empty containers and old rags according to local regulations. 

These products usually have a milky appearance when first applied, which makes thorough coverage easier. The milkiness will disappear as it dries leaving a clear coating..