Decking · Pressure-treated pine
How long does a pressure treated deck last?
InterNACHI's baseline chart gives deck planks a flat 15 years. The plastic tag stapled to the end of a treated board says LIFETIME LIMITED WARRANTY — and the document behind that tag is written by the preservative company, covers rot and termites only, and names splitting, checking, cupping, twisting and warping as things it does not cover. Those are the things a treated deck actually does.
Updated
The gap: the paper says “Lifetime” — The warranty is issued by the chemical company, not the mill and not the lumberyard: Great Southern Wood, whose YellaWood name is on the tag, states in the same document that it makes no warranties whatsoever. "Lifetime" covers one thing — structural failure, defined as the board no longer being able to do its job because of rot, fungal decay or termite attack. The paper then excludes the weathering of wood by name: raised grain, splitting, checking, cupping, twisting, warping, shrinkage and swelling are all outside it, as is any mould or mildew that is merely aesthetic. Coverage also lapses on boards ripped or sanded after treatment, on above-ground boards set less than six inches over final grade on a permeable surface, and where the construction does not let air move under the deck and between the boards. It cannot be transferred to the next owner. The remedy is replacement boards or a refund up to the original purchase price — never removal, delivery or installation — and a claim needs the receipts plus the end tag off every piece, filed within 30 days of finding the failure. Typical service life is still about 15 years. Warranty document (Koppers Performance Chemicals (YellaWood brand), checked 2026-08-27)
Typical service life: about 15 years
The baseline chart carries a single 15-year figure for deck planks and does not separate treated pine from any other decking wood. It is a flat estimate for the boards you walk on, not for the frame beneath them, which the same chart lists separately at 10 to 30 years.
Tier 3 · baseline chart (undated) Range from InterNACHI — Standard Estimated Life Expectancy Chart for Homes, checked 2026-08-27.
Treated pine's clock runs on wetting and drying cycles more than on heat. In the humid Southeast, boards that stay damp under shade go grey and soft on the early side of any published figure; in dry inland climates the same boards may stay sound for far longer while checking badly from the sun. The treatment resists the fungus, not the weather — which is precisely the line the warranty draws.
What the warranty paper actually says
Koppers Performance Chemicals (YellaWood brand) (Micronized Copper Azole Residential & Agricultural Limited Warranty) publishes a “Lifetime” limited, non-transferable, conditional warranty. The warranty is issued by the chemical company, not the mill and not the lumberyard: Great Southern Wood, whose YellaWood name is on the tag, states in the same document that it makes no warranties whatsoever. "Lifetime" covers one thing — structural failure, defined as the board no longer being able to do its job because of rot, fungal decay or termite attack. The paper then excludes the weathering of wood by name: raised grain, splitting, checking, cupping, twisting, warping, shrinkage and swelling are all outside it, as is any mould or mildew that is merely aesthetic. Coverage also lapses on boards ripped or sanded after treatment, on above-ground boards set less than six inches over final grade on a permeable surface, and where the construction does not let air move under the deck and between the boards. It cannot be transferred to the next owner. The remedy is replacement boards or a refund up to the original purchase price — never removal, delivery or installation — and a claim needs the receipts plus the end tag off every piece, filed within 30 days of finding the failure.
The warranty document itself , checked 2026-08-27.
What shortens it
- Boards laid bark-side down, so the annual rings cup upward and hold water in a shallow trough along every plank
- Tight or closed gaps between boards, which trap leaf litter and keep the underside damp long after the surface has dried
- Ground clearance under six inches over soil or a slab, the same condition the warranty itself carves out
- Cut ends and drilled holes left unsealed, which open untreated inner wood on species the treatment never fully penetrates
- Shade and constant wetting — sprinkler overspray, a downspout discharging beside the deck, planters sitting directly on the boards
Signs of wear to look for
- Deep checks opening along the grain, wide enough to catch a fingernail and running most of a board's length
- Cupping and twist that lifts board edges above the fasteners and makes the surface uneven underfoot
- Grey, fuzzy, raised grain that splinters when brushed by hand
- Soft, punky patches where a screwdriver pushes in easily, typically at board ends and over joists where water sits
- Fastener heads standing proud of the surface as boards shrink, cup and work loose season after season
The boards are one question and the frame under them is another: a ledger pulling away from the house, spongy joists, or posts moving at their footings are structure — that is an inspection question, not a web-page question.
Other decking materials
- Composite decking (wood-plastic) 8–25 yrs
- PVC decking (cellular PVC) 50+ yrs
- Western red cedar 15–25 yrs
- Redwood 10–30 yrs
- Ipe 25+ yrs