There's nothing quite like a deck or patio to saunter out on for that morning cup of coffee. Or evening libation. Or anything.
There's also nothing quite like wood for a deck. While building a wood deck is a lot of work, it is not as complicated as it seems. If you have an old concrete patio in the back that has served its time, you can put a wood deck right on top of it. If there's nothing there but a little dirt (mud in the spring, dust in the summer), you can build a deck that is on the same level as the house. Then there's no need for a stairway, at least from the house itself.
Here, we're considering building a deck directly on a concrete slab. This is where you can save, because the slab, if it is in reasonably good shape, will be the foundation of the deck, and the underpinnings of a deck are the most complicated and expensive parts.
It's simply a matter of putting sleepers on the concrete, and deck boards on top of the sleepers.
What kind of wood to use? Several kinds will do. The best is pressure-treated wood, usually fir or southern pine. It is so well filled with wood preservative that it will -- or should -- last indefinitely. Another good wood is redwood. If fir is used it should be treated with a wood preservative. Brushing or soaking (dipping) the wood with a preservative will make it last longer than untreated wood, but not much.
Incidentally, if you use pressure-treated wood, you can put the sleepers directly on the ground.
The sleepers that go directly on the concrete can be 2 x 4s set on their wide sides. If you want more height to the deck, use 4 x 16s and set them on their narrow sides. The bigger the sleepers, the harder it is to secure them to the concrete.
A concrete patio may be slightly slanted for drainage. If you want your deck level, you will have to shim the sleepers; that is, put narrow strips of wood under the low ends of the sleepers so they will be on the same plane as those on the high end. Shims must be placed wherever there is a gap (or at least a few feet apart) so the sleepers don't sag under weight. Shingles or thicker wood can be used, depending on how big the gaps are.
The best decking material is 2 x 4s. They allow the sleepers to be on three or four-foot centers. If you use 1 x 4s or 1 x 6s, the sleepers should be on 16-inch or 24-inch centers. You can also use 2 x 6s, but the wider the boards the more they are likely to warp.
The deck boards should be spaced, to allow rain to drip between them and onto the concrete, where it will drain away. Gaps may be 1/4 inch to 3/8 inch wide. You can make a template for the gaps or use a piece of plywood of the proper thickness. A 40-penny nail also works well.
You can put the boards at right angles to the sleepers or try an artistic approach and place them diagonally.
The sleepers can be secured to the concrete with concrete nails. These are grooved, hard steel nails that do, strangely enough, hold in concrete. The secret is to predrill the hole through the sleeper. Then, when the nail is driven into the concrete and the head approaches the top of the sleeper, do not countersink the nail into the wood or even set it flush; to do either is to risk breaking up the concrete.
Another method also will work. It is not so much a matter of securing the sleepers to the concrete, as of keeping them from going sideways. Drill a hole through the sleeper and 2 inches into the concrete. Then drive a 1/4 to 3/8-inch reinforcing bar (any steel rod will do) into the hole. You have to use a masonry bit to drill into concrete. The latter technique is the only way to go if you are using 4 x 6 or bigger sleepers.
Still another method is to glue the sleepers on with construction adhesive, which comes in a caulking cartridge that fits into a caulking gun.
Nail the boards on with nails big enough to go through the sleepers without hitting the concrete. For 2 x 4 sleepers and 2 x 4 or 2 x 6 boards, use a 10-penny nail (3 inches long). For nailing into 4 x 6 or bigger sleepers, use 16-penny nails (3 1/2 inches long). When nailing 1 x 4s or 1 x 6s, use 8-penny nails.
Use hot-dipped zinc galvanized nails. They'll resist rust. Even better, but far more expensive, are stainless steel or aluminum nails. Avoid using electro-plated nails.
Use two nails in each board over each sleeper. Regular galvanized nails are pretty thick, and may split the wood if you nail too closely to the edge. To prevent this, predrill the hole in the deck board, or use galvanized box nails, which have a narrower shank.
Redwood and pressure-treated wood can be left to weather naturally. Redwood will tend to get quite dark, while the pressure-treated wood will turn grey over the years. If want color, use a semi-transparent preservative stain. Clear preservative will hasten the turn to silver.
Use semitransparent or transparent stains; solid stains are not designed for horizontal surfaces such as decks, and will not work at all well.
Naturally, you would like the edges of your deck to look good, and to keep our vermin. You can nail a board across the ends of the sleepers the full length of the deck. (The sides will already be covered by the border sleepers.) When you nail such a board, be sure to have a half-inch gap to allow water to drain away. Screen this gap to keep out vermin.
The edge of deck next to the house needs special attention, to prevent water from running down the wall and into or onto deck boards and sleepers.
The easiest way to do this is to set the boards two or three inches away from the wall to allow natural drainage. Another, more complicated method would be to install aluminum flashing under the siding along the row of shingles or clapboards nearest the deck. The flashing is bent into an "L" shape, to guide the water onto the deck where it will drain through the gaps between the boards. Or it could be straight, to guide the water behind the deck boards but in front of the house siding.
Now, with the basic deck finished, you can go whole hog and try for fancy touches, such as a fence around the deck, benches, storage cabinets, steps, and maybe even a two-level deck.