What type of lumber for decks

Extremely dense and highly durable, these patio decking materials are rich in color and resistant to insects and decay and last about 25 years. But they are also expensive, heavy, and hard to work with — so hard in fact that you can't hammer a nail without drilling a hole first.

Avoid dark woods if your deck sees a lot of sun during the day because they will heat up like a frying pan. A step up from pressure-treated wood—and costing about three times more—are cedar and redwood. These woods contain natural defenses against rot and insects, and should last around 20 years, but they are soft and easily damaged by foot traffic.

Red cedar and redwood are both lightweight and stiff. Lighter-colored Port Orford Cedar is the hardest and most wear-resistant cedar. Cedar is from the same genus as redwood, so the two have similar properties, but the former is less dense and can flex more without breaking. It also has less natural oil, which makes it easier to stain. Cedar forests are more abundant than redwood forests, making cedar the eco-friendlier and less expensive option. In the past, redwood was more prized for its rich, red-brown coloring.

Both cedar and redwood need to be power-washed, sanded, and refinished every three years or so. The material can last decades, but like all woods, the sun soon fades their natural color to gray; a sun-blocking stain is required to keep the color sharp. A water-repellent wood preservative can help prevent fine splits from occurring. Composites are made to look like real wood and come in a wide variety of natural-looking hues and grain patterns. Made by combining a blend of plastic and waste wood fibers, these boards won't splinter and don't need to be stained or painted, thanks to a built-in UV resistance.

Keep children out of the work area. After it is cut, lumber is dried, planed, and smoothed, all of which reduces its thickness and width.

The nominal size of a board refers to the size before drying and planing; actual size means the size you actually get, and it's less than its nominal size in thickness and width. Posts larger than 4x4 are prone to twists and cracks; consider sandwiching 2xs instead.

Exotic hardwoods offer a more costly but extremely durable alternative to domestic woods. Ipe, for example, can triple your material costs—and that's if you use it only on the deck surface and railings.

On the other hand, ipe is twice as strong as PT Douglas fir. As more retailers bring these woods to market, prices might come down a bit, but they will probably never be competitive with PT lumber.

Sustainability is also an issue with these woods. Some of each species is cut from sustainable forests, but these products can be difficult to obtain.

Check with the Forest Stewardship Council for information on sustainable wood products. All of the exotic hardwoods are extremely dense and may prove difficult to work with. Pre-drilling is a must, as undrilled fasteners will split the boards. Fasteners made specifically for these woods are preferred to nails or screws.

Ipe is so dense that it neither needs nor will accept stains or finishes. Other species can be finished with hardwood stains or oils. Redwood and cedar look better than PT lumber, but only the heartwood naturally resists rot.

The light-colored sapwood may rot in a few years unless treated regularly with preservative. For a small deck 10x12 feet, for example , determine how much lumber you'll need by counting all the pieces of each size—foot 2x4s, 8-foot 2x6s, and so on. Add 10 percent to framing quantities and 15 percent to decking to allow for waste.

Lumber lengths are in even 2-foot intervals. If you will cut several lengths from a board, remember to allow for the saw kerf when estimating.

For larger decks, you can calculate the total square footage of decking you need by multiplying the length of the deck surface times the width. Allow for overhangs. Then buy enough lineal feet of decking to make up the deck area plus the waste allowance. Make actual counts of posts, beams, joists, and other framing members. Once you get your materials to the work site, protect them from direct sunlight and moisture, especially if you expect your deck building to spread out over several weekends.

And because plastic lumber contains no wood fibers, it is far more resistant to extreme weather conditions, decay, and cracks. The major advantages of composite versus wood decking include the fact that they never have to be treated, stained or sanded, and are low-maintenance. Not everyone will be a fan of synthetic products, but smart consumers should definitely do their research and consider the advantages. In fact, you might never come across one at all.

And bugs hate it. Another factor to consider is the fact that aluminum is much stronger than wood, and yet two to three times lighter.

This means you will have a more watertight deck. Believe it not, aluminum decking stays cooler in the sun than most other decking materials due to its heat-dissipation properties. As you can see, choosing the best wood for decks is not as simple as selecting your favorite color. Wood-composite decking cost two to three times more than pressure-treated wood, and PVC decking runs 10 to 15 percent more than wood-composites. Composite decking brands include Trex , Fiberon , and Veranda. Its powder-coated finish lasts virtually forever and it'll never peel or blister.

Aluminum can't catch fire, wood-boring bugs hate it, and it's percent recyclable. When compared with wood, composite, and plastic lumber, aluminum decking is three to four times lighter, yet two to three times stronger. It can be cut with the same saws and carbide-tipped blades used to cut wood.

Most aluminum decking comes in a variety of wood-grain finishes and colors. Most aluminum decking planks have interlocking edges, which create gap-free, watertight decks. Aluminum decking is available from such companies as LockDry , Versadeck , and Nextdeck. Interestingly aluminum decking actually stays cooler than most types of decking because of its superior heat-dissipation properties.

Dense materials, such as wood and composites, tend to absorb and hold heat for extended periods, creating hot surfaces. Type keyword s to search. Today's Top Stories. Guido Mieth Getty Images.