The measurement that makes this guide useful
Wood moves across its width as the moisture in the air changes, and the amount it moves is published, per species, by the USDA Forest Products Laboratory. That makes species selection an arithmetic question rather than an opinion, which is unusual and worth taking advantage of.
The number is called a dimensional change coefficient. It gives the fractional change in dimension per one percent change in moisture content, based on the dimension at 10 percent moisture content, and it is valid within moisture content limits of 6 to 14 percent, which covers everything that happens inside a house. Multiply it by the width of a panel and by the moisture swing, and you get movement in inches.
The local moisture swing, measured
The Wood Handbook publishes monthly equilibrium moisture content for outdoor conditions at a list of US stations. There are only two in California, Fresno and Los Angeles, and Los Angeles is the nearest listed station to San Clemente. This guide uses it and says so, rather than implying there is San Clemente data.
| Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|
| 9.4 | 10.2 | 10.5 | 10.4 | 11.0 | 11.7 |
| Jul 11.6 | Aug 11.2 | Sep 10.8 | Oct 10.6 | Nov 9.8 | Dec 9.9 |
Range 9.4 to 11.7, a band of 2.3 points across the whole year. The table's own note states the values were determined from the average of 30 or more years of relative humidity and temperature data from the National Climatic Data Center, and that the relative humidity data are averages of morning and afternoon values.
A 2.3 point annual band is mild by national standards, and that is genuinely good news for timber cabinetry here. The chapter does carry one caution worth repeating: “in some locations, early morning relative humidity may occasionally reach 100%. Under these conditions, condensation may occur on the wood surface, therefore surface fibers will exceed the EMC.” Coastal mornings are exactly that condition, which is an argument for a properly built finish film rather than for avoiding a species.
Wood Handbook chapter 13, Drying and Control of Moisture Content and Dimensional Changes→
The species table, with the sum done
Below, each species is shown with its published tangential coefficient and with the movement that produces across a 24 inch panel over the 2.3 point band above. Twenty-four inches is a realistic width for a single door on a wide base cabinet, which makes it a useful reference width.
| Species | Radial | Tangential | Movement across 24 in. |
|---|---|---|---|
| Sugar pine | 0.00099 | 0.00194 | about 0.11 in. |
| Black cherry | 0.00126 | 0.00248 | about 0.14 in. |
| Red alder | 0.00151 | 0.00256 | about 0.14 in. |
| Coast Douglas-fir | 0.00165 | 0.00267 | about 0.15 in. |
| Black walnut | 0.00190 | 0.00274 | about 0.15 in. |
| Red maple | 0.00137 | 0.00289 | about 0.16 in. |
| Yellow poplar, paint grade | 0.00158 | 0.00289 | about 0.16 in. |
| Northern red oak | 0.00137 | 0.00304 | about 0.17 in. |
| Yellow birch | 0.00256 | 0.00338 | about 0.19 in. |
| Sugar maple | 0.00165 | 0.00353 | about 0.19 in. |
| White oak | 0.00194 | 0.00376 | about 0.21 in. |
| True hickory | 0.00259 | 0.00411 | about 0.23 in. |
| American beech | 0.00190 | 0.00431 | about 0.24 in. |
Arithmetic: 24 multiplied by the tangential coefficient multiplied by 2.3. Coefficients are published per 1 percent change in moisture content, based on the dimension at 10 percent, valid within moisture content limits of 6 to 14 percent.
Construction beats species, every time
A fifth of an inch of movement across a door is nothing in a floating panel and a disaster in a glued one. That is the whole practical conclusion of the table above.
A stile and rail door works because the central panel sits free in a groove and can expand and contract. Glue it in, and the movement goes into the joint or into the panel, and eventually something cracks. A cope-and-stick joint with the panel free is the standard way to build one, and it is the difference between a door that ages and a door that fails. This is why the first question about any timber door should be about the panel rather than about the species.
The Wood Handbook’s own advice for lumber is the same idea stated generally: “Match the moisture content of lumber as closely as is practical to the equilibrium moisture content (EMC) conditions in service.” Its recommended moisture content values for interior woodwork, flooring, furniture and wood trim are 8 percent average with a 6 to 10 percent range for most areas of the United States, 6 percent with a 4 to 9 percent range for the dry southwestern area, and 11 percent with an 8 to 13 percent range for the damp, warm coastal area. The Handbook indicates which regions fall in which zone on a map figure that this guide has not read, so no claim is made here about which zone San Clemente sits in. The three published values are given as published.
The species in practice, one at a time
Red alder
The workhorse of Western cabinetry and the default for Spanish Colonial and rustic work. Coefficient 0.00256 tangentially, which is towards the stable end of the hardwoods. Soft enough to dent, which some people read as character and others as damage. Takes a stain evenly, which is unusual and useful. Knotty alder is the same species selected for visible knots, and it is the single most requested species in South Orange County kitchens with any Spanish influence.
Maple, sugar and red
Hard, fine-grained, pale, and the standard choice for painted and light-stained work. Sugar maple at 0.00353 is one of the higher-movement species in the table, which matters on a wide door and not at all on a drawer front. Maple is notorious for taking stain blotchily without a conditioner, which is a real workshop issue rather than a marketing one: if you want dark stained maple, ask how the shop handles it.
Red oak and white oak
Red oak at 0.00304 and white oak at 0.00376 are the two most common oaks in American cabinetry, and they are genuinely different. White oak is denser, more water-resistant and currently far more fashionable; red oak has the open, cathedral grain associated with 1980s and 1990s kitchens, which is exactly why so much of the hillside housing in San Clemente has it. Both are excellent cabinet timbers whose reputations move with fashion rather than performance.
Black cherry
Coefficient 0.00248, among the most stable hardwoods in the table, with a fine grain and a colour that darkens substantially over the first few years. That darkening is the thing to know before choosing it: cherry installed today will not be the colour it is in five years, and a replacement door made later will not match until it has caught up.
Black walnut
Coefficient 0.00274, stable, dark, and expensive. Walnut lightens rather than darkens with exposure, which is the opposite of cherry and surprises people. Usually specified for an island, a bar run or a feature wall rather than a whole kitchen, both for cost and because a room entirely in walnut is darker than most people expect.
Hickory
The hardest common cabinet timber and, at 0.00411, the highest-movement species in the table. Enormous colour variation between sapwood and heartwood, which is the reason people choose it and the reason others avoid it. A wide hickory door is the most demanding thing on this list to build well, and it is a good test of whether a shop floats its panels.
Yellow poplar and soft maple, paint grade
Coefficient 0.00289 for yellow poplar. Chosen for stability, workability and price rather than appearance, because the grain will be under opaque paint. This is not a compromise: a painted poplar frame around an MDF panel is a legitimate high-end specification, and it is what a great many expensive painted kitchens actually are. The reason MDF is used for the panel is that it has no grain direction at all and therefore no movement to accommodate.
Softwoods: sugar pine and Douglas-fir
Sugar pine at 0.00194 is the most stable species in the table and soft enough that it dents if you look at it. Coast Douglas-fir at 0.00267 is stiffer and stronger, with a strong vertical grain when quarter-sawn, and it turns up in Craftsman-influenced work. Both are appropriate for painted or rustic cabinetry and neither will survive a busy kitchen unmarked.
The other axes: hardness, colour change and cost
| Species | Hardness in service | Colour behaviour |
|---|---|---|
| Sugar pine | Soft, dents easily | Ambers gently |
| Red alder | Soft to medium | Ambers, warms with age |
| Black cherry | Medium | Darkens substantially, first few years |
| Yellow poplar | Soft, paint grade | Irrelevant under paint |
| Red oak | Hard | Ambers, warm undertone |
| White oak | Hard | Ambers less, cooler undertone |
| Sugar maple | Hard | Ambers noticeably, especially under clear coat |
| Black walnut | Medium to hard | Lightens with exposure |
| Hickory | Hardest here | High natural variation, ambers |
Colour behaviour is why a new door rarely matches an old one in the same species and specification. Clear finishes also yellow slightly on their own, independently of the timber underneath.
The coastal note that is actually true
Cabinet marketing near any coastline tends to claim that salt air destroys timber. The measured data says otherwise: a 2.3 point annual moisture band at the nearest listed station is a benign environment for wood. What does suffer within a few blocks of the water is plated steel, on hinges, slides and pulls, where thin decorative plating pits and then lets the steel beneath it corrode until the mechanism stiffens.
So the genuinely coastal specification decision is about metal rather than about species, and it is covered on the hardware page. Choose your timber on colour, hardness and movement; choose your hardware on corrosion.
How to specify a species properly
- Ask whether stile and rail doors float their panels, before asking about species at all
- For a wide door, check the species coefficient and expect a designed gap, not a tight fit
- If you want dark stained maple, ask specifically how blotching is controlled
- If you want cherry, understand that it will darken and that a later replacement door will not match immediately
- For painted work, poplar or soft maple frames with MDF panels is a legitimate high-end specification
- For a Spanish Colonial room, knotty alder is the default for good reasons, both visual and dimensional
- Ask for quarter-sawn if you want oak with minimum movement, and expect to pay for it
Door construction in detail is in the door styles guide, the carcass material question is separate and covered in the box materials guide, and what gets sprayed over the timber is governed by published rules set out in the finishes guide. The work itself is on the custom cabinets page.