Cleaning Deck Mold

Spring is the right time to clean your decking and railing. Keep in mind, when you build a deck with composite decking and railing, you get years of relaxing, carefree use when compared to traditional lumber decking. There’s no stripping, painting, sealing or staining necessary. Of course, thanks to nature, no product is maintenance free. But with Latitudes decking, a simple, occasional cleaning will prevent the buildup of dirt and chalk—as well as pollen and other debris that cause and accelerate the growth of mold or mildew.

When it’s time to clean your Latitudes composite deck, here are some easy-to-follow guidelines for great results. If you use a pressure washer, use a fan-style tip—and only use the washer to wet down or rinse your deck. Avoid high-pressure blasting that literally can drive dirt and spores deeper into the composite decking surface.

Typically, you can clean your deck with soap, water and a scrub bush or use a high-quality cleaner available at your home-improvement center. Most cleaners contain Sodium Percarbonate and a detergent. These types of cleaners are very effective in removing dirt while bleaching out mold and mildew stains—simply follow the label directions.

When you find stains, there are simple ways to deal with them. For rust stains caused by metal furniture and other sources, look for a deck cleaner containing oxalic acid. To wash away grease and oil stains, use any standard commercial degreaser. Typically, these will contain propylene glycol, sodium hydroxide and detergents.

If your deck has a stubborn grease or oil stain, try a small amount of spot remover or paint thinner. But use it sparingly and wash it away quickly. These products usually contain organic solvents that can attack the grain pattern in your composite deck. Whatever you use to clean your synthetic decking and railing, always perform a test in an inconspicuous area before you use it on the entire surface. Always be certain to read, understand and follow all label instructions.

Some cleaning products and inhibitors may be more effective than others, depending on your environmental conditions. And remember, the best way to manage stains—is not to have them occur. Always try to deal with spills before they have a chance to set-up.

Remember, that while mold and mildew can reappear on any exterior building surface, there are ways to manage them effectively on composite decking. Above all, sit back, relax and enjoy your low-maintenance, high-reward Latitudes composite lumber decking and railing. See additional tips for preventing mold and mildew from my past blog. Also watch our deck cleaning video.

After the leaves have fallen on and around your deck, consider giving your composite wood deck or pressure treated deck a thorough cleaning, especially in colder climates where snow could deter your decision to maintain your decking and outdoor living area. Cleaning your deck late in the year is always a good idea as it helps prevent the buildup of mold and mildew on the deck surface. By making sure all leaves and debris are swept off the deck surface before snow accumulates, your spring cleaning will be much easier.

It's important to clean bird droppings and common spills that happen throughout the deck season. You don't want these cleanable mishaps to turn into stains on your composite or lumber deck because they remained on the surface too long.

Scrub and rinse your deck
Start cleaning your composite decking or pressure treated decking by scrubbing the surface with soapy water. Start at the top of the deck railings and work your way down to the deck surface. It's necessary to remove the dirt and debris that accumulates on the composite deck surface. This will also prevent the build-up of pollen that can cause mold and mildew growth. Pressure washers should only be used at lower pressures to wet and rinse synthetic decking and railing. For ground-in soil you'll need to apply a detergent, scrub the deck surface with a course bristle brush and rinse thoroughly with water.

Apply a quality deck cleaner to the surface
Deck cleaners usually contain sodium percarbonate and a detergent, which is effective on normal dirt and grime and helps bleach out mold and mildew stains. Oxalic acid cleaners are effective on rust stains from metal patio furniture.

Watch our cleaning video or read care and cleaning instructions for Latitudes composite decking. For pressure treated decking, read our general maintenance guide (PDF).

Getting ready for the outdoor entertaining season means picking up after Old Man Winter. He can be rather untidy, so here’s how to get your treated lumber or composite lumber decking and railings back into mid-season form.

First, you’ll want to take some soapy water to all of that accumulated dirt and chalking. Start at the top surfaces and work down. If you’re using a power washer, use the low setting (high-powered blasting usually drives dirt deeper into the surface). Then go back over the surfaces with a good, general purpose deck cleaner making sure to follow the manufacturer's instructions. Use chemical spot removers sparingly on heavily soiled areas, and be sure to rinse them off quickly.

Different types of stains require different cleaners. For these and other essential facts, click through here for the whole story.

See how well Latitudes Capricorn® composite decking sheds stains with an enlightening mess test video.

Check out my other blog posts on deck care and cleaning:

• How to clean and maintain composite decking and railing
• Simple steps for cleaning a wood deck
• Preventing mold and mildew growth on composite decking

Spring is the start of the outdoor living season when homeowners begin to get their deck or patio ready for outdoor entertaining. Here are some general tips for cleaning your composite deck along with types of cleaning agents best suited for washing composite decking materials.

Wash and rinse your deck
Start cleaning your composite decking by washing with soapy water. Start at the top of the deck railing and work your way down to the composite deck surface. It's necessary to remove the dirt and chalking that accumulates on the composite deck surface. This will also prevent the build-up of pollen and debris that can cause mold and mildew growth. Pressure washers should only be used at lower pressures to wet and rinse synthetic decking and railing. Pressure washers should not be used to “blast-off” soiling agents; attempting to do so can drive the dirt deeper into the decking material. Test on an inconspicuous area before washing the entire deck.

Basic deck cleaning agents
Deck wash / cleaners usually contain sodium percarbonate and a detergent, which is effective on normal dirt and grime and bleaches out mold and mildew stains. Oxalic acid cleaners are effective on rust stains from metal patio furniture. Commercial degreasers contain propylene glycol, sodium hydroxide, and various detergents for removing grease and oil stains.

When cleaning composite decking, spot removers can be used sparingly on those stubborn grease or oil stains but should be washed off quickly with water, as it will attack the grain pattern. They normally include petroleum distillates, xylene, methanol, acetone, or other organic solvents.

Mold and mildew can be a nuisance on any exterior building surface, regardless of the material. If the conditions are right, they will spawn on wood, plastic, concrete, metal and other surfaces. Mold formation is most prevalent in consistently wet, shaded areas. Spores from the natural environment are carried by the wind and commonly land on decks surfaces. It is important to note that the appearance of mold and mildew is a function of nature, not necessarily a deficiency with any of the material on which it grows.

Deck Cleaning
Periodic washing with soap/detergent and water will help remove surface dirt. This will also help prevent the buildup of pollen, debris and spores that can cause and accelerate mold/mildew growth (it also helps to remove deck mold). Caution: A pressure washer should not be used to “blast” mold/mildew or soils from a deck surface. The abrasive nature of the water stream can potentially damage the material by driving the spores into the material, which may create a morechallenging problem to remediate. A pressure washer with a fan-tipped nozzle should be used only to lightly wet or rinse wood or composite deck surfaces. 

There are many deck wash and exterior cleaning products available at retail. It is important to make sure you use a cleaner specifically intended for your application. After selecting a product, be certain to read, understand and follow all instructions supplied by the manufacturer. Some cleaning products and inhibitors may be more effective than others, depending on the environmental conditions your deck is subjected to. Additionally, it is always a good idea to test the cleaner in a small, inconspicuous area prior to applying it to the entire deck.

Mold Inhibitors
As with deck washes, there are several mold-inhibitor products available from paint stores, hardware stores, online outlets and home centers to help prevent long-term mold/mildew growth. For any product selected, be certain to read, understand and follow all instructions provided by the manufacturer. Depending upon the environmental factors affecting your composite lumber or treated wood deck, some preventive cleaning products may be more effective than others. It may be necessary to try more than one product. For ongoing preventive maintenance, follow the manufacturer’s recommendation.