First few minutes
Just happened? Do this first
- Scrape off as much sap as you can with a spoon or dull knife.
- Blot from the edges toward the center rather than rubbing.
- Test any alcohol on a hidden spot first.
- Sweep away leaves and debris before you start.
Tree sap and pine pitch are sticky resins that water alone won't dissolve, so a hose won't clear a spot on the deck. Softening the sap first is what lets it lift, and the longer it sits the more grit it grabs. A deck can be damaged in the wrong hands, so go easy with a pressure washer and keep the scrubbing gentle.
If you're removing sap from a painted deck, keep the pressure washer well back from the paint and use lighter steps. Pitch that has hardened on bare wood calls for a slower approach, so don't rush it. If soap and water leave a sticky film, an adhesive remover finishes the job.
Before you start
What decks & wood fences can take
Safe to use2
- Water
- Oxygen bleach
Use with care5
- Soaking
- Chlorine bleach
- Solvents (alcohol, spot removers)
- Acids (vinegar, lemon)
- Scrubbing and abrasives
8 items
What you'll need
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- Spoon or dull putty knifeLifts loose sap without cutting into the paint or wood. (opens Amazon)
- Rubbing alcohol (70% isopropyl or 90% denatured)Softens the sap on bare wood. Use one with no added color or fragrance. (opens Amazon)
- Vegetable shortening or petroleum jellyThe softener to use on painted boards.
- Clean clothsFor dampening with the softener and blotting from the edges in.
- Mild dish detergentMixed with water to wash off the greasy film. (opens Amazon)
- Stiff synthetic-bristle brushScrubs along the grain on wood. (opens Amazon)
- Garden hoseRinses the soap and residue off the boards.
- Plastic drop clothProtects nearby plants. Spraying them with water dilutes any overspray. (opens Amazon)
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6 steps
Step by step
Step 1 of 6
Scrape off the loose sap
Sweep away leaves and debris first, then lift off as much sap as you can with a spoon or dull knife. Work gently so you don't gouge the paint or the wood underneath.
Step 2 of 6
Test a hidden spot first
Pick a hidden board, such as the underside of a step, and test rubbing alcohol on it. Check the paint or wood for softening, dulling or a change in color before you go near the sap.
Step 3 of 6
Soften the sap from the edges in
Dampen a cloth with rubbing alcohol for bare wood, or rub on vegetable shortening or petroleum jelly if you're worried about the paint. Blot from the edges toward the center rather than rubbing, so the sap doesn't spread across the board. Give the softener a little time to work before you move on.
Careful. Ventilate the area and keep the alcohol away from flames and pilot lights.
Step 4 of 6About 15 minutes
Wash off the greasy film
Mix mild dish detergent into water and scrub the spot with a stiff synthetic-bristle brush, working along the grain. Keep the detergent wet on the spot for about 15 minutes, misting it with the hose if it starts to dry, since the soap and water cut the greasy film the softener leaves behind.
Careful. Skip steel wool and wire brushes, since the iron they leave behind stains wood.
Step 5 of 6
Rinse the spot thoroughly
Rinse with a garden hose until no soap or residue is left on the board. Work one section at a time so the soap doesn't have a chance to dry while you go.
Tip. Check from a low angle in daylight, where any leftover film shows up.
Careful. Never let soap or cleaner dry on the boards.
Step 6 of 6
Check when dry and repeat
Once the wood is fully dry, feel the spot for any tacky or dark patch. If it's still sticky, repeat the softening and washing on that spot only.
If you'd rather buy than mix
Best products for tree sap on decks & wood fences
Choose a mild dish detergent and a stiff synthetic-bristle brush for the wash. For softening, use 70% isopropyl or 90% denatured alcohol with no added color or fragrance.
Goof Off Adhesive Gunk Remover Gel
How we picked these: each product is made for this type of stain, its maker doesn't warn against using it on decks & wood fences, and its directions fit the steps above.
Finished the steps? How does it look?
Nice work. Let it dry completely and check it again in good light. Here is what done looks like:
How to tell it's really gone →A faint mark usually needs one more round, not a stronger product.
If the stain was already dried or set, the method changes.
Old, dried or set-in stains →When to call a professional →How to tell it's working
The spot is clean when it looks like the boards around it and feels smooth, with no tackiness left. Check it once it's dry, because wet wood can hide a sticky patch. A dark mark that stays after that is often grime the sap held onto, so wash that spot again.
What changes for yours
Adjust for your decks & wood fences
Hardened pitch on bare wood
Pitch that has dried into a crust on bare wood is handled like hardened sap: soften it, then scrape off the softened layer before you wash. On unpainted boards, rubbing alcohol is the main softener, so you can work it in with a little more patience than you would on paint.
If a mark stays in the bare wood once it's dry, lightly sand that spot and wipe off the dust. Keep the sanding to the mark itself so the surrounding boards keep their texture.
Sap on painted rails or posts
Painted rails and posts need the gentler softener, so use shortening or petroleum jelly first and keep the alcohol for bare wood. Rub lightly and blot, because hard scrubbing can wear through paint on those narrow edges.
Rinse the spot with the hose and let it dry fully before judging the color, since a dull patch can look worse while it's wet. If the paint looks softened or changed, stop and wash the area with mild dish detergent only.
Weathered gray boards
On a gray deck, the sap sits on wood that has already lost its surface color, so the spot can look darker than it really is. Use the same softener and soap sequence, and add a commercial deck cleaner or brightener only if the surrounding boards are dirty or covered in mildew.
If the wood's natural color has leached out, it stays silver when dry, and that is normal. Leave those fibers in place instead of sanding the whole board to chase the spot.
Sap between deck boards
Sap that has worked down between boards is hard to reach with a brush, so wrap a cloth around a dull knife and work the softener into the gap. Use only a small amount so it doesn't run down onto the surfaces below.
Rinse the gap well with the hose after the wash, then let it dry before you decide whether another round is needed.
Old, dried or set-in stains
Old sap that has hardened into a glassy crust needs a longer softening round before it lifts. Work rubbing alcohol into it with a cloth or cotton swab, then scrape the softened layer off with a spoon or dull knife. Wash the spot again after each round so no greasy film builds up.
If it still won't lift, turpentine is the last resort for hardened sap, and it should only go on after a hidden-spot test. Treat it as a solvent you use with care on wood, and never as your first choice.
If a mark is still there once the board is dry, it may have soaked into the grain. Lightly sand just that spot and wipe off the dust rather than sanding the whole deck.
Vinegar, baking soda, peroxide and more
Do home remedies work on tree sap on decks & wood fences?
Most of these household remedies are for food, fabric or metal, so most of them don't belong in a sap fix on a deck. Only the alcohol and the dish soap appear in the steps. The rest are skipped, and oxygen bleach is one to keep off paint.
Works2Skip3Avoid1
What makes it worse
Mistakes to avoid
Don't let the sap sit
Sap that stays on the deck picks up dirt and binds more grime the longer it's there, so a small spot becomes a bigger job. Start scraping as soon as you see it.
Don't use a tornado or narrow-stream tip
Narrow-stream and rotating tornado tips aren't for decks. Use a fan tip at the lowest pressure that still cleans, spray along the grain, and test the setting on a hidden spot first.
Don't bleach pressure-treated boards
Chlorine bleach breaks down the lignin in pressure-treated wood and corrodes metal fasteners. It also harms nearby plants and doesn't kill mildew spores, and sap doesn't need it at all.
Don't wet-clean old CCA decks around kids and pets
Wetting old CCA wood raises the arsenic on its surface, and bleach releases chromate. Keep kids and pets off the wet boards until the deck has dried.
When to call a professional
Pressure washing a deck takes care, because the wrong hands can damage the boards, so hire someone if you're unsure. If the deck is old CCA lumber, don't cut or burn it, since sawdust and smoke contain arsenic, and replacing it is the safer route.
Questions
Will tree sap come off a painted deck?
Often, yes, as long as you soften the sap and wash off the greasy film it leaves behind. A faint mark can remain on the paint, so test a hidden spot first and go slowly.
Can heat or a hair dryer loosen it faster?
No. Dryer heat sets sap, so skip the dryer, heat guns and hair dryers on the spot. The softener and scraping do the job without heat, and that is the safer route for paint and wood alike.
Is rubbing alcohol safe on a painted deck?
It can be, if you test it first. Dampen a cloth, touch it to a hidden board and check the paint for softening or a change in color. If the paint reacts, switch to vegetable shortening or petroleum jelly.
Does vinegar help with sap?
No, skip vinegar; alcohol or shortening softens the sap, and mild dish detergent washes off the greasy film. The alcohol or shortening softens the sap, and mild dish detergent washes off the greasy film.
Can a pressure washer remove sap on its own?
Not on its own, because the sap has to be softened before it lifts. Once it's softened and washed, a fan tip at low pressure can help with the rinse, spraying along the grain.
What if sap is still there after washing?
Repeat the softening and washing on that spot only, once the wood is dry. If a mark still shows, lightly sand just that spot and wipe off the dust.
Tree Sap on other materials
Other stains on decks & wood fences
Start from the bigger picture
How we know this
Every method, amount and warning here comes from university extension services, industry bodies and product makers. We read them, check every step for unsafe combinations and changed amounts, and write it up so you can follow it.