How you deal with the odor will depend on its cause.

Remove the Cause

Once you’ve determined the cause of the odor, remove the offending material.

Its lifeless body decomposed and you began smelling that unavoidable, horrid odor as time went by.

Closeup of wooden deck floor boards

The Spruce / Michelle Becker

Hold your breath and put whatever material is causing the smell into a plastic bag and tie it shut.

Warning

Wear gloves if you’re handling decaying material directly.

Rinse with water and the odor should be gone.

Materials needed to remove odors under a deck

The Spruce / Michelle Becker

If not, repeat until the odor dissipates.

For Dog Urine

This smellcan get quite pungent, especially if it builds up.

Chances are that the deck has been a bit neglected and needs to be treated and sealed.

Checking underneath the deck for any obvious odors or causes of odor

The Spruce / Michelle Becker

you’re free to either do this yourself or hire a professional.

After that,sandit and apply oil-based wood sealer (if the deck is surfaced with wood).

This needs to be done only every five years or so.

Removing the cause of under deck odors

The Spruce / Michelle Becker

A hand-held power sander will make the job easier.

The solution you use can vary, depending on how strong you want to go.

Use a broom or araketilted on an angle to reach the space if it’s difficult to fit underneath.

Spraying vinegar between deck floor boards to remove odor

The Spruce / Michelle Becker

Chicken wire, standard screening, or wood planks installed with spacers are great options.

Be sure to check for rodents first and remove the animals from the area before sealing it off.

Scrubbing the deck with a hydrogen peroxide baking soda mixture

The Spruce / Michelle Becker

Sprinkling baking soda on dog urine odor coming from the deck

The Spruce / Michelle Becker

Sprinkling coffee grounds on cat urine odor coming from the deck

The Spruce / Michelle Becker

Scrubbing the deck with a mildew remover solution

The Spruce / Michelle Becker