Green Cleaning: Decks

Wooden decks (as well as docks and siding) take a beating throughout the year with all the exposure to rain and dirt. So how do you get rid of the grit and get your deck ready for guests? Proper cleaning is the first step.

Scrub a dub

If your deck is very dirty then the only way to get it really clean is to get down on your hands and knees and give it a deep scrubbing with a hard-bristled brush. Most home experts and contractors advise against using a power washer (or pressure washers) since they can leave the wood frayed and uneven. However, a bit of elbow grease combined with the right cleaner goes a long way.

Cleaners to avoid

You want to avoid using the usual chlorine bleach or conventional deck soaps, which can alter the pH of water. Bleach also gives off harmful fumes, and the residue in your rinse water will end up in your garden or the lake, where it’s no friend to terrestrial and aquatic life. And if you're using bleach to clean up mildew—forget it! A study conducted by Professor Jeffrey Morrell, Dept. of Wood Science, Oregon State University found that bleach "doesn't eliminate the surface micro flora." It doesn't kill the roots of the mould, only bleaches it so we think it's been cleaned away, when it hasn't.

Conventional soaps are not much better since they may also contain unsustainable ingredients and toxic chemicals that can contaminate nearby water or soil. It can also kill off beneficial bugs and drive the birds from your garden.

Natural soaps

Baking soda and vinegar are always our first choice for any cleaning product, but if need more cleaning power, try Dr. Bronner's Sal Suds for decks. Its mild formula is made with pure fur and spruce essential oils and it works well on hard surfaces. With no synthetic dyes or fragrances, it biodegrades rapidly after doing its job. Home Soap's All Purpose Home Household Cleaner is another great all-purpose soap that will get the deck sparkling. Its blend of coconut derivatives and essential oils cut grease and dirt, plus it’s easy on your hands and the garden.

Oxygen clean

A new kind of bleach containing sodium percarbonate (not to be confused with sodium bicarbonate, i.e., baking soda) makes an excellent deck cleaner. This white powder is non-toxic, non-flammable, biodegradable and soluble in water. Much less harsh than chlorine bleach, it reacts with water to form hydrogen peroxide, which cleans and brightens. It's particularly good at lightening heavily darkened wood but is also an excellent stain remover (also handy in the laundry room) . There are several brand names sold at grocery and hardware stores but the secret is to look at the percentage of sodium percarbonate in the mixture. Cheaper brands will have up to 40 percent filler. You want a higher percentage of the actual sodium percarbonate.

Avoid the dirt

Once you've gotten your deck in top shape there are some things to watch out for:

•    You're asking for it with bird feeders on the deck. Bird droppings will stain your deck and make it difficult to keep clean. So feed the birds in your garden away from your deck.

•    Plants are great on the patio but plant containers can leave behind some insightly marks. Moisture trapped underneath containers will leave hard-to-remove stains and may cause rot. Buy containers with legs or place them up on small blocks to ventilate. You can also move the container around the patio; heavy pot can go on wheels.