How to Build a Deck: 8 Steps, 6–12 Weekends (IRC 2021)

For a 320 square foot deck, plan on 8 to 12 weekends as a first-timer, which works out to roughly 60 to 80 hours of actual labour. Someone who has framed before finishes in 4 to 6 weekends and 30 to 50 hours. Those figures cover swinging a hammer only, and the calendar is always longer than the labour. Most authorities having jurisdiction take one to three weeks to return a permit, composite decking and railing systems commonly carry two to four week lead times, and you will wait on two inspections that stop work until they happen: the footing inspection before you pour concrete, and the framing inspection before any decking goes down. Add it up and a realistic window from decision to final walk-through is 8 to 16 weeks. The single biggest schedule saver is ordering long-lead materials while the permit is still being reviewed rather than after it lands.

Yes, and a deck is the most achievable major project on a typical house: bigger than a weekend repair, smaller than an addition, and squarely inside what a competent weekend carpenter can finish. The skills that actually decide the outcome are narrower than people expect. Layout comes first, because squaring the deck with mason line and equal diagonals sets everything downstream, and an error there compounds through joists, decking and stairs. Ledger flashing comes second, because that detail is water management on your house wall rather than on the deck, and getting it wrong rots structure you cannot see. Cutting and fastening are the easy parts. The honest disqualifier is not intelligence but tool familiarity: if you have never run a circular saw, build something smaller first. The other disqualifier is scope, since a multi-tier deck or one more than 16 feet above grade leaves prescriptive code territory and needs an engineer.

The minimum kit is a cordless circular saw, a drill and impact driver, a framing square, a four-foot level, a 25-foot tape, mason line and stakes, and either a post-hole digger or a rented auger at about $40 to $80 a day. A good 6-1/2 or 7-1/4 inch circular saw runs $100 to $200 and a drill and impact set $200 to $400, which puts a first-timer total at roughly $400 to $800 including the small stuff. Three optional tools pay for themselves on a big deck: a 10-inch mitre saw at $150 to $400 for tread and rail cuts, a framing nailer for the joist work, and a pneumatic stapler if you are running joist tape for composite. Do not skip the safety items either. Safety glasses, gloves, knee pads for the hours spent on the decking, and an N95 for cutting pressure-treated lumber all belong on the list.

Materials are typically 40 to 50 percent of an installed deck price, so the labour you replace is the larger half of the bill. In practice a competent do-it-yourselfer with free weekends saves 50 to 60 percent of the total project cost. On a $20,000 contractor quote that is $10,000 to $12,000 kept, against roughly 80 hours of weekend work, or about $125 to $150 an hour for your time. For most homeowners that is two to three times what their day job pays, which is the real reason deck DIY is popular. Two caveats keep the number honest. First, you still pay for the permit, the inspections and any re-inspection fees, and tool purchases come out of the saving on your first deck. Second, the saving assumes the work passes. A framing mistake caught by the inspector costs a weekend; the same mistake caught after the decking is down costs several.

Plan and permit, then layout and footings, then the ledger, then posts and beams, then joists, then decking, then stairs, then railing and the final inspection. That sequence is not a preference, it is what the inspection schedule and the physics enforce. Never pour footings before the permit is issued, because an authority can make you dig them up. Never pour concrete before the footing inspection, since depth, diameter and bearing layer are exactly what the inspector came to see. Never lay decking before the framing inspection, because covering the joists hides the hangers, ledger bolts, flashing and lateral anchors that the inspection exists to check, and pulling boards back up is the most demoralising rework on the project. Within that order there is one useful piece of flexibility: order long-lead composite and railing while the permit is in review, so the material arrives about when the framing is ready for it.

The easiest part is the decking itself. Once the framing is right, laying boards is repetitive work with a simple rhythm: gap them consistently at 1/8 inch, two fasteners per joist crossing on pressure-treated, or hidden clips nested board to board on composite. It is the stage that finally looks like a deck, and it goes quickly. The hardest parts are both at the start. Layout is hard because squaring the perimeter with equal diagonals is what every later measurement inherits, and being half an inch out of square is invisible until your last board runs tapered against the house. Ledger flashing is hard because it is the one detail where a mistake damages the house rather than the deck: Z-flashing has to tuck under the siding above and drape over the ledger top, or water tracks into the wall. Spend your extra hours on those two and the rest follows.

Most mistakes are recoverable, and the stage you catch them at decides the cost. A joist hung too high comes down by pulling the hanger nails and repositioning. A footing poured shallow can often be extended by another six inches on top. Inconsistent decking gaps are a matter of backing out screws and resetting boards against a spacer. The expensive category is structural sizing: a footing of the wrong diameter or a joist run past its allowed span means demolishing and redoing that section, because no fastening trick fixes an undersized member. This is the practical argument for treating the framing inspection as a free audit rather than a hurdle. Everything the inspector checks is still visible and reachable at that moment, and the same defect found after the decking is installed costs a weekend of removal before you can even start the repair.

No. In all 50 states a homeowner may build a deck on their own property without holding a contractor licence. What you do need is the building permit, and with it the inspections that come attached: footing, framing and final. Permits are not optional for a structure of this size, and skipping one tends to surface later at the worst possible moment, when a buyer requests records during a sale or an insurer asks after an incident. Where the rule does bite is help. Unpaid help from friends or family is fine, but paid help generally has to be licensed, so you cannot hire an unlicensed labourer for the framing weekend. Rules vary by authority, so confirm locally before you plan around anyone else's hands. The permit application itself wants a site plan, a construction plan, lumber specifications and code references, which is why a calculator that outputs an IRC-cited bill of materials saves real time here.

Failing is common and rarely serious. The inspector writes up what is wrong, you fix it, and you schedule a re-inspection, which costs about $50 to $150 in most jurisdictions. The failures that recur are predictable: a missing lateral-load anchor at the ledger, hangers that are undersized or fastened with deck screws instead of the specified nails or structural screws, footings that did not reach frost depth plus bearing, and baluster gaps that let a 4-inch sphere through. Every one of those is a parts-and-a-weekend problem when caught at the framing stage. The way to make failure cheap is to invite it early. Book the footing inspection before you pour and the framing inspection before a single deck board goes down, so the items under review are still exposed. Most decks that fail the first time pass on the second.

Hire out when one of four things is true. Your time is genuinely worth more than about $100 an hour, in which case the 80 hours is the expensive part of the project. You have never used a circular saw, since a deck is a poor place to learn. Your design leaves prescriptive code, which includes multi-tier decks and anything more than 16 feet above grade, because those need engineered design rather than the IRC tables a DIY build leans on. Or you live in a low labour-cost market, where the saving from doing it yourself shrinks against the risk. Outside those cases the arithmetic favours DIY for most homeowners, typically netting two to three times an average hourly wage. A middle path exists and is underused: hire a contractor for the ledger, footings and framing, then do the decking, stairs and railing yourself.