blog image

Cleaning Under Your Deck: Maintaining Your Outdoor Area

January 24, 20244 min read

Many homeowners diligently clean the visible parts of their decks but often overlook the hidden underbelly. Under your deck, mold, mildew, algae, grime, and other unsightly elements can accumulate over time, impacting the appearance and utility of your outdoor space. Regularly cleaning beneath your deck is crucial to prevent problems and make the most of your outdoor living area. In this guide, we'll walk you through the steps for effective under-deck cleaning.

Pre-Cleaning Preparations: Considerations Before You Begin

Before embarking on your under-deck cleaning project, it's essential to make some preparations:

1. Determine Deck Type: Whether your deck is made of wood or composite decking, the cleaning products and procedures will vary. Your local home improvement store will have suitable cleaning agents for different deck types.

2. DIY Cleaning Solutions: You can create your cleaning solution that is safe for both wood and composite decks, as well as your yard, pets, and the environment.

  • For wood decks, combine 2 gallons of warm water, 2 cups of powdered oxygen bleach, and a quarter cup of ammonia-free dish soap. Be cautious not to mix products containing ammonia and chlorine bleach, as it can produce toxic fumes.

  • For composite decks, use 1 cup of white vinegar, 1 gallon of warm water, and a quarter cup of baking soda. Expect some fizzing as you mix the solution.

3. Protective Gear: Since you'll be working overhead, it's advisable to wear old clothing or a protective suit over your attire. Don't forget gloves, safety glasses or goggles, and headgear. Ensure your footwear is supportive and non-slip, as the work area may become slippery, and a ladder may be necessary.

Steps to Clean Under Your Deck Space

Now that you're adequately prepared, let's commence the cleaning process:

Step 1: Clear the Area: Remove any items from under your deck or shield them to prevent contact with cleaning products and moisture.

Step 2: Remove Debris: Employ a broom or blower to clear away dirt, debris, and cobwebs from beneath the deck. While doing this, inspect for loose fasteners, damaged wood, or any items in need of repair, and address them first.

Step 3: Wet the Surface: Use your garden hose to spray the underside of your deck, preparing it for cleaning. If you're utilizing a homemade cleaning solution, mix it now.

Step 4: Apply the Cleaner: Employ a scrub brush, soft sponge, or sprayer to apply the cleaning solution to the deck's surface. Avoid using a power washer or pressure washer with homemade solutions to prevent potential clogs from undissolved granules. Be generous with the solution and create a lather while brushing.

Step 5: Allow to Sit: Let the cleaning solution sit for 15 minutes. For stubborn grime, apply a bit more solution and gently scrub with a stiff-bristled brush.

Step 6: Rinse: Utilize your garden hose to rinse off the solution, but exercise caution as the area may become slippery. If specific spots require extra attention, repeat step 5.

Step 7: Allow to Dry: Allow the entire deck to dry completely before uncovering or replacing items underneath. This is also an opportune moment to apply a sealer to your wood deck.

Step 8: Share Your Achievement: Take pride in your hard work and show off the clean under-deck area to your friends and family. Cleaning under your deck can be a messy task, deserving acknowledgment!

How Often Should You Clean Under Your Deck?

Maintaining a clean under deck is essential for the overall health and safety of your deck. Performing this cleaning routine twice a year, in the spring and fall, will ensure your outdoor space remains enjoyable, and any issues are promptly addressed.

Signs Indicating Urgent Cleaning Needs

If you spot green, brown, or black patches on your deck boards or structure, consider spot-treating them without cleaning the entire under-deck area. Regular biannual cleaning should prevent urgent situations. Additionally, keep an eye on your gutters, downspouts, drainage system, and railings to ensure they're in good shape, as preventive care is preferable to repair.

Other Methods to Enhance Under Your Deck

To maximize the space beneath your deck, contemplate transforming it into a dry area to create an additional outdoor living space. The Trex® RainEscape® is an under-deck drainage system that diverts water from the deck, effectively forming an outdoor room with protection from the elements. However, remember that even with such a system, regular cleaning twice a year remains necessary to keep your outdoor space in pristine condition.

general contractor in Philadelphia
Back to Blog


Our Happy Client

Lorem ipsum dolor sit amet, consec adipisicing elit, sed do eiu tempor incididunt ulabo dolore magna aliqua. Ut enim ad

David Markers


Lorem ipsum dolor sit amet, consec adipisicing elit, sed do eiu tempor incididunt ulabo dolore magna aliqua. Ut enim ad

David Jection



Emergency Services Available 24/7

Mon - Fri: 7:00am - 6:00pm

Sat: 8:00am - 2:00pm

Sun: 8:00am - 12:00pm

Office: 3622 Genesee Pl Philadelphia, PA 19154

Call 215-350-2885




Copyright © Expert General Contracting. All rights reserved.