How often should you reseal your deck?
Grumpty's answer
Every 24 months
Why bother
Bare wood grays, splits and rots. A thorough-tier job. Skippable when life's busy, worth it when it isn't.
What the job involves
- Clean it first. Sweep the deck, then scrub it with a deck cleaner to shift the dirt, grime, and mildew. If the old finish is flaking, strip that off too. Sealer over muck is just sealed-in muck.
- Sand the rough patches and any splinters with 60 to 80 grit so the wood can drink the sealer in, then let it dry right through. Damp wood won't take it.
- Wait for the weather. You want two dry days at 50 to 90 degrees F so the finish can cure. Sealing before rain is sealing before disappointment.
- Put the sealer on with a brush, roller, or pump sprayer. Work it into the cracks, the railings, and the steps, not just the easy flat bits. Then leave it alone until it's dry before anyone walks on it.
Do it yourself, or pay someone?
DIY-able over a weekend if you're fit and the weather holds. Materials are about $0.25 to $1 per square foot. Paying a pro averages around $972, usually $563 to $1,399. Worth hiring out for a big, multi-level, or badly weathered deck, where the prep is the real slog.
What skipping it costs
$500 to $4,000 to replace boards once water gets into them, against the roughly $972 it costs to seal the thing. Spot rot is the cheap end, around $200 to $500. Widespread board replacement is the dear end. An unsealed deck soaks up water instead of shedding it, and over a few wet seasons the boards gray, splinter, cup, and rot. Let the rot reach the joists and the ledger that holds the deck to the house and it's no longer about looks, it's about whether the deck stays up. A coat of sealer every couple of years is the cheap end of that math.
Signs it's overdue
- Tip a cup of water on it. If the water soaks straight into the boards instead of beading up, the seal's gone. That's the whole test.
- The wood's gone silvery-gray. That's UV chewing through the surface fibers, not just a bit of weathering.
- It feels rough underfoot and starts throwing splinters where the finish has worn away.
When to start thinking about it
This usually means booking someone, so the grumbling starts 30 days ahead to leave time to line it up. Mark it done and Grumpty sets the next one, every 24 months, so you can go back to forgetting it exists.
Questions people ask
How often do I actually need to reseal it?
Every one to three years for most decks. Clear or lightly tinted finishes and harsh climates lean toward yearly. Solid stains and covered decks can stretch to five. Don't bother counting the years though. Tip some water on it, and when it stops beading and soaks in, it's time.
Is sealing the same as staining?
Not quite. A clear sealer waterproofs but does little against UV, so the wood still grays on you. Stain adds pigment that blocks the UV. Plenty of products do both at once, which is why the two jobs get muddled together. Pro sealing runs about $0.75 to $4 per square foot. Staining runs higher, roughly $1.75 to $4.50.
What if I just never seal it?
The bare wood drinks up water, then swells, cracks, grays, and eventually rots. Spot rot repair is $200 to $500. Once whole boards go it's $500 to $4,000 to swap them, and rot that reaches the structure can mean a full rebuild, $4,300 to $12,600 once the old one's torn out. The roughly $972 reseal is the cheap way to never meet those numbers.
Related jobs
Stop keeping this one in your head
This is one job. Your home has dozens more, each on its own clock. Grumpty is a free home-maintenance app: add a job once, it tracks the date, grumbles when it's due, and rolls it forward the moment you mark it done.
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