Why decks hold the smell
A lot of the backyards around Washington Park and its neighbors have a deck added off the kitchen or a rear addition, often only a foot or two off the ground. That narrow space is hard for people to see into and easy for a skunk to dig under. Spray under a deck rarely stays put: it coats the underside of the boards, runs down joists and soaks into the dirt.
Wood type matters. Unsealed cedar and older pressure-treated pine are porous, and the underside of deck boards is almost never stained or sealed even when the top is. Composite boards absorb less, but the wooden framing beneath them still does. Gaps between boards let the smell rise straight up to anyone sitting on the deck, and the back door or kitchen window is usually a few feet away.
Deck materials and how they respond
| Material | How much it absorbs | Practical note |
|---|---|---|
| Unsealed cedar | High | Treat the undersides directly; may need more than one application |
| Older pressure-treated pine | High, especially weathered boards | Check for rot while the boards are accessible |
| Composite or PVC boards | Low on the surface | The wood framing below still needs attention |
| Soil and gravel beneath | High | Often easier to remove the top layer than to treat it fully |
| Landscape fabric | Moderate | Usually replaced if it took a direct hit |
Working under a deck
Confirm the space is empty
Watch for activity at dusk, or ask a wildlife operator to check. A mother with young under a deck in late spring is a different situation from a single wandering adult.
Find access
Skirting panels or a single removable board can often provide enough room. Lifting a few boards is sometimes faster than crawling under a low deck.
Address the soil
Rake out debris and nesting material, then either treat or remove the top few inches of soil in the spray zone and replace it with clean fill or gravel.
Treat wood undersides and framing
Use a neutralizer that reacts with sulfur compounds, applied so it actually wets the wood. A fine mist on the surface may not reach far enough.
Close the gap
Hardware cloth buried along the perimeter and bent outward in an L shape is a common way to stop digging under the edge.
Questions to ask before deck work starts
- Will the soil be treated, removed, or both?
- How will the undersides of boards be reached?
- Are any boards likely to be damaged or replaced to get access?
- Is the treatment safe on composite decking and on stained wood?
- What should be done about the sprinkler zone near the deck?
General information for Washington Park, not a quote or professional advice. In an emergency, call 911.