Wood decks: what to know
Types of wood for decks
- Pressure-treated pine: the most common deck lumber in Pennsylvania. Copper-based preservatives are forced into the wood so it resists rot and insects. It costs the least and is the standard for deck framing, even under composite boards.
- Cedar: the heartwood resists rot on its own and weighs less than pine. It is softer, dents more easily, and costs more. Left bare, it weathers to silver gray.
- Tropical hardwoods such as ipe: very dense and long-lasting, but they cost the most, are hard to cut, and need holes drilled before screwing.
Ground-contact vs. above-ground lumber
Treated lumber is rated for how wet it will get. Posts, and anything close to soil or hard to replace later, should be rated for ground contact. Many builders now use ground-contact lumber for all framing, because joists and beams stay damp longer than the tags assume.
Cutting a board exposes untreated wood inside, so builders brush a preservative onto cut ends.
Screws, nails, and hardware
The copper in treated lumber corrodes plain steel. Screws, nails, joist hangers, and brackets should be hot-dip galvanized or stainless steel and rated for treated wood. Hardware that rusts out is a common reason old decks fail.
When to stain a new wood deck
New treated lumber is often still wet from the plant. Stain won't soak in until it dries, which can take a few weeks to a few months.
To test, sprinkle water on the boards. If it beads up, wait. If it soaks in, the wood is ready.
Upkeep
- Clean and re-stain or seal every two to three years. The floor wears faster than railings.
- Semi-transparent stain shows the grain and wears evenly. Solid stain covers more but can peel and needs scraping before recoating.
- Reset nails or screws that pop up, and replace cracked boards before they spread.
Railing options
- Composite or PVC: matches composite boards and needs little upkeep. Usually comes in white, black, and wood tones.
- Aluminum: powder-coated, won't rust, and has thin balusters that block less of the view.
- Cable: stainless steel cables for the most open view. The end posts must be strong enough to hold the cables tight, and the cables must stay tight to pass the 4-inch rule below.
- Wood: the lowest cost. Needs the same stain or paint schedule as a wood deck.
Any deck more than 30 inches above the ground needs a guard at least 36 inches tall, with gaps too small for a 4-inch ball to pass through. Railing posts are a common weak point, so they should be through-bolted or set in tested brackets, not held by a few screws.
Stairs, landings, and multi-level decks
Sloped yards and walkout basements often call for a tall deck or two levels joined by steps. Splitting a high deck into levels breaks up the height, can leave room for a covered patio below, and gives separate spaces for cooking and sitting.
Wide stairs with a landing are easier to climb and can double as seating. Code limits how tall each step is and how shallow each tread can be, and the steps in a flight must match within a small margin. Stairs with four or more risers need a handrail you can grip, a flight can rise only about 12 feet before it needs a landing, and the bottom step should sit on a firm base, not bare soil.
Is wood right for you?
Wood often makes sense if:
- You want the lowest upfront cost.
- You like real wood grain and don't mind staining every few years.
- The deck gets full sun, where wood stays cooler underfoot than most composite.