How often to restain a deck in Tennessee humidity

Most decks around here want attention every two to three years. Railings and fences can usually go longer. Here's what the sources say, and what moves the number up or down.

What the sources say

Source	What they say
Angi¹	Restain every two to three years
Bob Vila²	Oil-based every 3–5 years, water-based 2–3, solid 4–5
USDA Forest Products Lab³	Semi-transparent on decking: 2–3 years on new smooth wood, 3–6 years on weathered rough wood
USDA Forest Products Lab⁴	Clear water-repellent sealers: about 1 year on exposed deck surfaces

Those are averages. The lab's own table says its numbers are for an average location in the continental United States³. Chattanooga isn't average.

Why Tennessee is harder on decks

We get about 55 inches of rain a year here⁵, and average humidity is about 72%, and highest in September⁶. Wet wood that dries slowly grows mildew, and mildew breaks down a finish from the top. Add strong summer sun on open decks and you get wear from both sides.

What makes yours last longer or shorter

Shorter

Full afternoon sun on the deck floor
Heavy shade and leaf piles
Clear or very light finishes (less pigment, less UV protection)
Dogs, grills, planters, kids

Longer

Vertical surfaces: railings, fences, siding
Good airflow under and around the deck
Semi-transparent with good pigment
A yearly wash and a quick check

The cheapest way to keep a deck nice

Recoat before it wears through. A maintenance coat on a faded deck costs a fraction of stripping a failed one. That's the whole idea behind our maintenance plans, and why our dashboard reminds us to call you before your deck needs it.

And check the structure while you're at it. The North American Deck and Railing Association recommends homeowners check their deck every year⁷.