Cedar vs Redwood: Decks, Fences, Siding

Western redcedar and redwood are the two naturally durable softwoods sold for decks, fences, siding and outdoor furniture in North America. Both are light, stable and reddish. The difference most people miss is that the redwood sold today is mostly young-growth, which the Wood Handbook rates lower in decay resistance than the old-growth redwood that built redwood’s reputation. This page compares western redcedar with both.

Cedar vs Redwood: the numbers

Property	Western redcedar	Redwood (old-growth)	Redwood (young-growth)
Janka side hardness, 12% MC	350 lbf	480 lbf	420 lbf
Density at 12% MC	22.4 lb/ft³	28.0 lb/ft³	24.5 lb/ft³
Weight per board foot	1.86 lb	2.33 lb	2.04 lb
Bending strength (MOR), 12% MC	7,500 psi	10,000 psi	7,900 psi
Stiffness (MOE), 12% MC	1.11 million psi	1.34 million psi	1.1 million psi
Crushing strength parallel to grain	4,560 psi	6,150 psi	5,220 psi
Shrinkage green to ovendry, tangential	5.0%	4.4%	4.9%
Shrinkage, radial	2.4%	2.6%	2.2%
Shrinkage, volumetric	6.8%	6.8%	7.0%
Tangential / radial ratio (cupping tendency)	2.08	1.69	2.23
Width change per 1% MC, flatsawn (Table 13-5)	0.234%	0.205%	0.229%
Heartwood decay resistance (Table 14-1)	resistant	resistant	moderately resistant

USDA Wood Handbook FPL-GTR-190: hardness and strength Tables 5-3b and 5-5b (12% moisture content), shrinkage Tables 4-3 and 4-4, dimensional change coefficients Table 13-5, decay resistance Table 14-1. * density estimated with Handbook Eq. 4-9. Averages for small clear specimens, not design values.

What the numbers mean

Hardness: Redwood (old-growth) is 37% harder than Western redcedar (480 against 350 lbf), so it resists dents from furniture feet, dropped tools and wear correspondingly better.
Weight: Redwood (old-growth) is 25% heavier. A 1 x 6 board 8 feet long (4 board feet nominal) weighs about 9.3 lb in redwood (old-growth) and 7.4 lb in western redcedar at 12% moisture content.
Strength and stiffness: Redwood (old-growth) is 33% stronger in bending and 21% stiffer. Stiffness is what decides how much a shelf of the same size sags under the same load.
Movement: a flatsawn board 10 in wide that goes from 6% to 12% moisture content (a dry winter to a humid summer indoors) swells about 0.140 in (1/8 in) in western redcedar and 0.123 in (1/8 in) in redwood (old-growth), from Handbook Eq. 13-2 and the Table 13-5 coefficients. Allow for this in table tops, panels and floors.
Decay resistance of the heartwood: Western redcedar: resistant; Redwood (old-growth): resistant; Redwood (young-growth): moderately resistant. Sapwood of every species has low decay resistance.
The percentages above compare the first two columns; the table also lists Redwood (young-growth) for comparison.

Appearance, working and what to watch for

Western redcedar is lighter and softer, with a spicy smell and colour ranging from pale straw to dark reddish brown. Redwood is a little heavier and harder, with a more uniform red colour. Both are among the most stable woods in the Handbook, with low shrinkage, so they lie flat as siding and resist checking. Both are soft: deck boards of either will dent under furniture and high heels.

For decay resistance, buy heartwood. Sapwood of every species, cedar and redwood included, has low decay resistance, and the pale sapwood boards common in lower grades will rot in ground contact. Neither should be buried; for posts in the ground use pressure-treated lumber rated for ground contact. Both woods contain extractives that stain black with plain steel fasteners, so use stainless steel or hot-dipped galvanized nails and screws.

Grades and finishes

Price differences between cedar and redwood often come down to grade. Clear heartwood grades of either are expensive; knotty and construction grades are cheaper and include more sapwood. For the longest life, buy heartwood grades, keep boards off the ground, and leave gaps for drainage and air. A penetrating, pigmented exterior stain slows weathering and checking; left bare, both woods weather to grey within a year or two. Both are soft, so pre-drill near board ends to avoid splitting.

Which to choose: verdict by use

Use	Better choice	Why
Fences and fence boards	Western redcedar	Usually the cheaper durable option, light and easy to cut.
Deck boards	Either (heartwood grades)	Redwood is a little harder; both dent. For high wear consider a dense hardwood.
Siding and shingles	Western redcedar	The traditional shingle and shake wood: stable, light and splits cleanly.
Outdoor furniture and planters	Either	Both stable and decay resistant in heartwood grades.
Fence posts in the ground	Neither	Use ground-contact pressure-treated posts.

Frequently asked questions

Is cedar or redwood more rot resistant?

In the Wood Handbook, western redcedar heartwood is rated resistant, old-growth redwood resistant and young-growth redwood moderately resistant. Most redwood on sale today is young-growth.

Is redwood harder than cedar?

A little. Western redcedar has 350 lbf of Janka hardness, young-growth redwood 420 lbf and old-growth redwood 480 lbf.

Which lasts longer for a deck, cedar or redwood?

With heartwood boards, good spacing and a finish renewed every few years, both last many years. Sapwood and poor drainage shorten life more than the choice of species does.

Sources and method

All property values are read from our parsed copy of the USDA Forest Products Laboratory Wood Handbook: Wood as an Engineering Material (FPL-GTR-190, 2010), a US Government publication in the public domain, the same data as the wood species database. The percentages and the board examples above are our arithmetic on those values. The values describe small, clear, straight-grained specimens: real boards with knots or sloping grain differ, and structural lumber is sized from graded design values in your local building code, not from this table.

Last reviewed: 24 October 2026. How we build and check our data: methodology and corrections. Spotted an error? Please let us know.