Deck Maintenance and Cleaning

Should you stain or paint your deck?
Many professionals do not recommend painting your deck. The problem with painting a deck is that most deck surfaces are horizontal, so the paint just “lays” on the deck. As a result, those areas hold water.
Painting, or using a solid-color stain with no sealer, will only help trap that moisture in the wood. So, as your deck boards expand and contract with variations in temperatures and weather conditions, paint begins to chip and you end up with peeling paint, rotting wood and other potential problems.
A quality stain and sealer, though, penetrates the wood grain to seal it, while also allowing moisture to escape from the wood. It won’t chip, peel or crack as the deck wood swells and shrinks. The more tinting the stain has, the better protected your deck will be from fading and moisture.
You've probably heard that you should wait a year before staining and sealing a deck to "season the wood." Many experts will tell you that this isn't true, and waiting can cause early water damage to the wood.
Before you stain the deck, you should have a professional power wash and clean the deck to remove any remaining stain, sealant, dirt and grime. A common issue power washing professionals see is homeowners who get a bit overzealous with the amount of pressure they use and cause splintering and other damage to the wood.
If you do tackle the staining yourself, you’ll want to make sure the deck is dry – two to three days in dry weather is typically sufficient – after it’s been cleaned and then apply either a clear sealer or a semi-transparent stain. Many products contain both a sealer and stain. An oil-based or semi-transparent stain offers the most natural look.
Staining a deck can be a time-consuming job. What you think could be a weekend project could end up taking weeks if you do it yourself. A quality deck maintenance company can offer the best suggestions for your specific situation to help you get the longest-lasting finish possible.

Be sure the wood used for your deck is protected from the elements. (Photo courtesy of member James H. of Egan, Minnesota)
Deck sealing
Unfortunately, for exposed decks, they need to be re-stained every few years. Even the best stain fades eventually; especially in high-traffic areas. Since moisture is one of the biggest threats to a deck, this step will help extend your deck's life and value.
To test your deck, sprinkle some water onto it and if the water stops beading and instead just seeps into the wood, you'll know that it's time to reseal the deck.
The best results come from using a quality deck sealer. This is not an area where you should skimp on the quality of the product you buy. Allow your deck to dry from any cleaning first. You can use a foam roller or a pad on a long handle. A special applicator are available that hold sealant in a reservoir, which makes the job easier.
Water-blocking sealants will extend the life of the wood. Additional protection comes from staining your deck. The stain provides an extra block from ultraviolet light, which causes graying.
Wear a respirator or dust mask while working with these products, and be sure to follow the manufacturer's instructions.
Deck cleaning
Whether or not your deck looks dirty, you should wash it. Not only is a dirty deck unattractive, the slippery surface poses a safety risk. Mildew and mold will cause damage if not removed. Pressure washing does the best job at blasting away dirt.
Sweep the deck regularly to reduce debris buildup. Leaves and dirt will break down and cause damage and stains over time.
When cleaning, follow any directions included with the deck cleaner. A long-handled scrub brush will make the work go quickly. If the deck is small, a good scrubbing can replace pressure washing. You can apply a mixture of water and a small amount of bleach. Rinse the mixture well before doing any other work.
Larger decks need pressure cleaning twice a year, at the beginning of spring and again in the early fall. You do not need to own a power washer because rentals are available. If you're uncomfortable with using a pressure cleaner, check Angie's List for local professionals.
Deck maintenance tips
The main factors affecting wear and tear on a deck are exposure to the afternoon sun, pets and kids.
When starting the task of deck maintenance, you’ll first want to inspect the surface of your deck, as well as the steps and handrails, for signs of stress. Look for broken or rotting boards, curling, cracking or loose areas. Replace boards as needed to prevent further damage and possible injuries.
Check for loose or missing nails, bolts or screws. These fixtures hold the deck together, so it's important to thoroughly inspect them at least once a year. Drive any loose nails back into place with a hammer, and use a drill with a screwdriver attachment to tighten existing screws and replace missing fasteners.
Use a high-power flashlight to check for damage to the structural supports under the deck. Animals or insects can eventually make your deck unusable. If you see any sign of a problem, such as chewed boards, contact a pest-control professional.
Wood will lose its color over time, slowly turning gray as it ages and accumulates damage and debris. Most wood cleaners will restore some of the original color by removing the grime that's causing the discoloration. Additionally, you could use a wood brightener, which may also restore some color.
As always, be sure to seal the deck after cleaning or brightening the wood to ensure that it continues to look refreshed until the next treatment.
Rot, where the wood is literally falling apart, is the worst-case scenario for an unprotected deck. Not only is rot unsightly, but it can also undermine the integrity of the deck itself. If the deck has been sealed but still shows signs of rot, it's important to check the area after the next storm to see where the water is coming from.
Often, you may discover a gutter issue or a problem with a fixture that is funneling water onto a particular area of the deck. Rot is also a big problem around handrails or stairs, where it's more difficult to effectively seal the area.
Fixing rot calls for repair, inspection and resealing. Repair any affected boards while inspecting the posts and beams to ensure the deck remains stable. Then, once only good wood is left, completely seal the deck so the rot doesn't return.
Certain types of wood will shrink over time as it dries out, which may create gaps in your deck. Unfortunately, the only way to correct this problem is to remove the boards and replace them.
Decks are often installed by inexperienced homeowners, which can affect their structural integrity. If your deck has any "give" to it when you walk on it, there's a good chance your deck needs structural repair.
Check the structure underneath the deck to ensure that the ledger boards, joist hangers and post connections are all complete and secure.