To clean a deck is probably the most labor intensive part of restoring this outdoor living space. Once the deck is clean it may actually be in better shape that was thought. The first step is to clean between decking boards. Maximum circulation of air should be maintained around each deck board. Buildup of debris between deck boards keeps wood moist, slows down drainage and encourages mildew growth. The important things is to spray an area with water and then use a putty knife to scrape out whatever debris remains. If the deck boards are set so close that a hose cannot clean between them, it is simply a matter of slipping a handsaw into the cracks to work the blade up and down, It is also possible to widen the gap between tightly spaced boards by making a pass with a circular saw with the depth of the blade set to match the thickness of the wood.



A deck eventually can turn grey from dirt tracked over and ground into it. Mildew can also build up making the wood slippery when it is wet. Of course the hardest weathering comes from the ultraviolet rays of the sun which tend to break down the lignin in the wood which is a plasticlike polymer that binds the cellulose fibers together. Degraded lignin is cellulose in minute strands which give the deck boards an aged, grey surface. In order to rejuvenate the deck it is necessary to determine what problems ail the deck and to choose the proper cleaning method that would work best.

In order to determine if the deck is just dirty, blend a mixture of water and laundry detergent and then use a stiff fiber brush to scrub the solution into a small deck area. When the solution is rinsed off and the area is clean, then the problem is dirt and the deck can continue to be washed in a similar manner and eventually rinsed with a hose. Mildew can be tested for by applying undiluted household bleach to a small, out of the way area of deck. Let it stand for 30 seconds and immediately rinse it with water. Mildew is at least part of the problem if the deck surface is clean.

Staining is also caused by chemicals in the wood that are drawn to the surface as a result of weather exposure. It can also be caused by the presence of iron from the use of ungalvanized nails or some other metal. Use oxalic acid to test for these stain problems. This substance is available at home centers and hardware stores. Simply mix 4 ounces of the oxalic crystals with 1 quart of water. It's also possible to purchase and use an oxalic acid-based cleaning product. Apply either liquid to a small out of the way deck space. Let it stand for 5 minutes before scrubbing it off with a stiff fiber brush and giving the area a finishing rinse.

Once the source of the deck discoloration has been identified it is time to seek out deck cleaning or deck restoring products. Make a point to check the ingredients for these products. Oxalic acid will clean stains caused by wood chemicals or by iron and will brighten a mildewed surface but it does not kill mildew. Chlorine based products will kill mildew, however, it may also leave the wood looking washed out. There are products on the market that are less toxic than bleach or acid. This is important for the person applying the product as well as for the environment. The sodium percarbonate in many of these products breaks down into hydrogen peroxide which bleaches and assists in the removal of the greyed cellulose cells. The sodium carbonate produced in many of these products also cleans the wood. Once completed, it becomes a simple matter to brush the wood with a stiff fiber brush and rinse the deck surface.

There are other deck cleaning restorative products that are also environmentally friendly. These actually dissolve the weathered cellulose without damaging the healthy wood cells. A good rinsing will complete the process of removing the dissolved wood cells for good. When cleaning a deck it is always a good idea to work safely. Wear protective gloves, goggles and in some cases proper footwear when applying the cleaning product. Wear a respirator when using a pressure sprayer and when scrubbing. Wear old clothes as bleach can easily discolor clothing. Never make the mistake of mixing different commercial cleaners or mix them with any household cleaner unless directions indicate it. NEVER MIX BLEACH WITH ANY TYPE OF PRODUCT THAT CONTAINS AMMONIA. Protect the plants and greenery around the deck by the use of plastic sheeting.

Once a homeowner has successfully mastered the steps of how to clean a deck it is time to begin the process of refinishing it in order to keep it looking its best and to get the longest life possible from it.