Decking · Redwood
How long does a redwood deck last?
The NAHB's 2007 life-expectancy study gives wooden decks about 20 years and then splits that figure three ways by climate in its own footnote: 10 to 15 years in the South, 20 to 30 in the North. It does not separate redwood from any other decking wood, and no mill sells redwood decking with a warranty — so on this page there is a number with a date on it, and nothing to set beside it.
Updated
Typical service life: 10–30 years
The 2007 study's headline figure for wooden decks is about 20 years under ideal conditions; the range here is the study's own comment on that row — "Dry areas last 20-25, South 10-15, North 20-30" — and it covers decking wood as a category, redwood included but not named. The USDA Forest Products Laboratory's life-cycle study of redwood decking used a 25-year service life for the same product, which lands in the upper half of that band.
Tier 3 · baseline chart (2007) Range from National Association of Home Builders — Study of Life Expectancy of Home Components, checked 2026-08-27.
Redwood was a regional material long before it was a national one, and it does best in the climate it came from: cool, dry-summer coastal California, where boards dry between rains. Take the same boards into humid Southeast summers, or into a shaded northern yard where snow sits on the deck for months, and the wet-time goes up while the extractives that protect it stay the same. Under snow, the deck spends part of every year at the damp end of its own range.
Why there is no warranty bar here
Redwood decking is graded commodity lumber and the mills publish grades, installation literature and life-cycle studies rather than a warranty term. The distinction that actually predicts how a redwood board behaves is not a brand but a grade: heartwood grades such as Construction Heart carry the decay-resistant extractives, and grades containing sapwood do not. Almost all redwood decking sold now is young-growth rather than old-growth timber, whose heartwood is the more durable of the two, and no paper compensates for that difference.
What shortens it
- Sapwood content — grades that permit sapwood put wood with no natural decay resistance on the same deck as wood that has it
- Young-growth stock, whose heartwood carries fewer of the extractives that made old-growth redwood last
- Standing water on the boards from planters, mats and furniture pads left in place through wet seasons
- Iron fasteners and hardware, which stain redwood black and soften the wood immediately around them
- Pressure washing and aggressive sanding, which strip the soft, extractive-bearing surface off a comparatively light wood
Signs of wear to look for
- Boards fading from red-brown to buff and then silver-grey, which is surface weathering rather than decay
- Dark, damp-looking bands directly over each joist, where the board never dries out
- Soft or crumbling end grain at board ends and around fastener holes
- Black staining haloed around screws and nails
- Long splits and raised, splintering grain across boards that get full afternoon sun
How a redwood board is faring underfoot is visible; whether the beams, joists and post connections carrying it are sound is not — that is an inspection question, not a web-page question.
Other decking materials
- Pressure-treated pine about 15 yrs
- Composite decking (wood-plastic) 8–25 yrs
- PVC decking (cellular PVC) 50+ yrs
- Western red cedar 15–25 yrs
- Ipe 25+ yrs