Deck FAQ

Most composite and PVC decking ships in 5-1/2 inch boards; some brands also offer 7-1/4 inch (wider). Wood almost always comes in 5/4 x 6 (actual 5-1/2"). Wider boards mean fewer gaps to sweep leaves out of, but a higher cost per sqft and slightly more visible cupping over time on wood. My take: stick to the standard 5-1/2 unless you really want the modern plank look and your budget supports the 15 to 20 percent premium for wider boards.

Hidden fasteners like CAMO Marksman or the Cortex plug system give you a board face with no visible screws. They add about $0.50 to $1.00 per sqft in materials plus 15 to 25 percent to install time. On composite, hidden fasteners are almost standard now since every premium brand publishes a hidden-clip system. On pressure-treated, visible stainless deck screws are still the norm and honestly look fine once the deck weathers. Splurge on hidden if you're specing Trex Transcend or AZEK Vintage.

Lag screws or Ledger-Lok structural screws into the house band joist, staggered two rows, every 16 inches. Flash the top of the ledger with aluminum or copper Z-flashing tucked behind the house siding. Use Simpson Strong-Tie DTT2Z tension ties at each end. Every deck collapse I've read about started with a failed ledger connection, almost always from nails instead of bolts or from skipped flashing that let water rot the band joist behind the ledger. Bolts and flashing are non-negotiable.

A poured concrete patio runs $6 to $12 per sqft installed. A pressure-treated deck runs $22 per sqft. So for pure cost, patio wins 2x to 3x. But a patio can't elevate above a sloped yard without retaining walls, can't match a second-story door height, and is harder to repair if the slab cracks. If your yard is flat and at-grade with the house, patio is the cheaper path. If you have any elevation drop or need to match a door threshold, deck wins on practicality even though it costs more.

Most residential deck framing is 16 inches on center for pressure-treated 2x8 joists, which handles composite and wood decking fine. Some premium composite (Trex Transcend, AZEK) recommend 12 inches on center for diagonal installs or for spans over 12 feet to meet their warranty terms. Check the manufacturer spec sheet before you frame. The extra joist every 4 feet costs about 30 percent more in framing material but dramatically stiffens the walking surface.

Southern yellow pine 2x8 joist, 16 inch on center, spans about 11 to 12 feet for a standard 40 psf live + 10 psf dead load. Douglas fir is slightly better. Reduce spans by 2 to 3 feet if you're supporting a hot tub or heavy outdoor kitchen. Always pull your exact span from the IRC table R507.5 or your local building department's prescriptive tables. Don't eyeball it from a forum post.

Minimum 12 inches below frost line, or 42 inches, whichever is deeper. Minnesota and Michigan push you to 48 inches. Texas and Florida allow 12 to 18 inches. Diameter should be 12 inches minimum for a 4x4, 16 inches for a 6x6. Use Quikrete fast-setting concrete, usually 2 bags per hole. Crown the top so water runs off the post base. A deck footing that freezes once because you cheated the depth by 4 inches will heave 2 inches by spring, and that's a rebuild.

Joist hangers (LUS28 for 2x8, LUS210 for 2x10), hurricane ties (H2.5A at every post), post caps (BCS2-3/4 or PC64Z depending on post size), DTT2Z tension ties at ledger ends, and FJBR ribbed framing bolts if your deck is over 5 ft elevated. I buy the galvanized Z-Max line at Home Depot; the stainless is overkill unless you're in a coastal salt-air environment. Budget $250 to $450 in Simpson hardware for a typical 320 sqft deck.

Every 2 to 3 years on pressure-treated and cedar. Every 1 to 2 years in extreme sun or rain climates. The first year after install is the most critical, the wood has to dry for 6 to 8 weeks then get a first coat of penetrating stain like Ready Seal or Cabot. Skip that first-year stain and the boards will cup and crack within 2 winters. Composite needs zero stain, ever. That's the trade.

Stain has pigment that colors the wood; sealer is clear. A quality penetrating stain (Ready Seal, Penofin, Cabot Australian Timber Oil) does both, it seals and adds color. A pure sealer like Thompson's WaterSeal adds water resistance but no UV protection, so the wood still greys. For most homeowners a semi-transparent penetrating stain is the right answer, one product that protects and colors. Avoid film-forming stains (the "deck paint" category) because when they fail they peel in big sheets and refinishing turns into a sanding nightmare.

Sweep off all leaves and debris in late October. Leaves trap moisture under the pile and rot the surface. Check every railing post and bench for wobble; tighten hardware. On wood decks, put a fresh coat of stain on any weathered sections. Don't leave potted plants on the deck over winter, the saucers hold water and freeze, cracking pots and staining boards. If you have a hot tub or grill on the deck, cover them or move them. That's the full checklist. Takes 90 minutes.

Not unless the deck was engineered for it. A 7-foot hot tub with water and people weighs 4,500 to 6,000 pounds. Standard deck framing (2x8 joists 16" on center) handles 40 psf live load, which works out to about 2,500 pounds spread over the footprint, nowhere near hot tub weight. You either build a dedicated footing pad under the tub location, or you redesign the deck framing with doubled joists and extra footings specifically for the tub load. Engineer stamp usually required.

If you have full sun exposure, yes. A pergola with a retractable canopy or climbing vines cuts direct sun by 50 to 70 percent and makes a deck usable in July. Cost: $3,500 to $8,000 for a 10x12 cedar pergola, more for aluminum. DIY pergola kits from Home Depot or Menards run $1,200 to $2,500 and are doable in a weekend if the deck framing can support the posts. Check joist span and add blocking where pergola posts land.

Yes, but the cost is real. Screening a 320 sqft deck adds $8,000 to $18,000 depending on roof style and framing. You're building a full roof structure, adding knee walls, screen panels, and a door. The deck itself might need structural upgrades to support the roof load. If screening is in your long-term plan, spec the deck framing for a potential roof at build time (oversized posts, doubled beams). Adding it later is doable but expensive.

Remodeling's 2024 Cost vs Value report puts a standard wood deck addition at roughly 50 to 65 percent cost recovery at resale. Composite tracks lower, around 40 to 55 percent, because the upfront cost is higher. A deck doesn't usually pay itself back dollar-for-dollar, but it moves houses faster and tends to attract buyers in warmer climates. If you're building for resale, go pressure-treated and keep it simple; if you're building for yourself and plan to stay 10 plus years, spend on composite and enjoy it.