Decks · Service

Deck installation, judged from the ledger out

A deck is a structure, not a floor you put outside. We match you with vetted local builders and tell you what actually decides whether yours is safe in twenty years — starting with how it attaches to your house.

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In short

What is deck installation?

Deck installation is the construction of an outdoor structural platform — footings into stable soil, a frame of beams and joists carried on posts, a surface fixed to that frame, and guards and stairs where the code requires them. In almost every jurisdiction it is permitted work with scheduled inspections, because a deck carries people at height. The decking you pick is the last decision, not the first.

Triggers

Signs you need deck installation

Your back door opens onto a drop, a set of temporary steps, or nothing at all
You have a usable garden you only ever look at, because there is nowhere flat to sit
Grade falls away from the house steeply enough that a patio would need a retaining wall to work
You are adding a hot tub, an outdoor kitchen or seating that needs a level, load-carrying surface
The existing structure is old enough or damaged enough that a builder has told you it is not worth repairing
You are finishing a renovation that left a new door or slider stranded above grade
Planning permission or an HOA has already approved a footprint and you now need someone to build it

Seeing something not on this list? Browse decks problems by symptom →

The job

How deck installation actually works

Siting — before anything is drawn

Where the deck can go is decided by setbacks from your property lines, easements, septic fields, buried utilities and whichever doors it is meant to serve. Sun and prevailing wind decide whether you will actually use it. A good builder walks the site and asks what time of day you expect to be out there.

Watch for: A quote produced from a photo and a tape measure over the phone. Utility locates are free in most places and are not optional; a post hole through a service line is a very expensive afternoon.
Permit and plan submission

Most jurisdictions require a permit for a deck, and many require one regardless of height. The submission usually needs a plan showing the framing layout, the footing locations, how the deck attaches to the house, and the guard and stair arrangement. Requirements are local — what your neighbouring county wants can differ from what yours does.

Watch for: A builder who offers to skip the permit to save you money, or who asks you to pull it as a homeowner so the inspection record sits against your name rather than theirs. Both are warnings, and unpermitted structural work reliably surfaces at resale and at claim time.
Footings and ground work

Holes are dug to whatever depth local code requires for your frost conditions and soil, and footings are formed and poured or set. This is the part of the deck nobody ever sees and the part that decides whether it stays level. Depth, diameter and bearing requirements are set by code and by your soil — they are not a builder preference.

Watch for: Footings placed shallow, or posts set straight into the ground in a climate that freezes. A deck on inadequate footings does not fail dramatically; it heaves, racks, opens gaps at the ledger, and pulls its stairs out of true over several winters.
The ledger connection — the one that matters

If the deck attaches to the house, it hangs off a ledger board fixed to the house framing. This connection carries a large share of the deck load and it is the single most common origin of catastrophic deck failure. Correct practice involves fastening into actual structure rather than sheathing or brick veneer, and flashing the connection so water cannot sit behind it and rot the rim joist it is bolted to.

Watch for: No flashing. It is invisible once the boards are on and it is the reason old decks fall off houses — the fasteners are fine, the wood they are bolted into has quietly turned to compost. Ask to see the ledger flashed before the frame closes it in. If a builder cannot explain their ledger detail, get another builder.
Framing — posts, beams, joists

Posts land on the footings, beams span the posts, joists span the beams, and the whole assembly is tied together with rated structural connectors rather than nails alone. Where a ledger is not practical — some brick veneers, some stucco, some rim conditions — the deck is built freestanding on its own posts instead, which is a legitimate solution and not a compromise.

Watch for: Undersized members or over-long spans. Allowable spans depend on species, grade, spacing and load and are published in the code your jurisdiction adopted; they are not something to eyeball. This is exactly what the framing inspection exists to catch, which is why you want the inspection.
Framing inspection

In most jurisdictions an inspector looks at the deck open — footings, ledger, connectors, framing — before anything covers it. This is your one free structural audit, performed by someone with no financial stake in the job.

Watch for: Decking laid before the framing inspection has happened. If boards go down first, either the inspection was skipped or someone is going to be pulling boards back up. Neither is a good sign.
Decking, guards and stairs

The surface goes down, then guards and stairs are built. Guard height, the loads a guard must resist, baluster spacing and stair rise and run are all code-governed, and the numbers differ between jurisdictions and sometimes between residential and other occupancies. Fastening method varies by material — some boards are face-screwed, some use hidden clips, and some need specific gapping for expansion.

Watch for: Guard posts bolted only through the deck boards rather than to the frame. A guard is a safety component that has to resist someone falling against it; if it is fixed to the surface instead of the structure, it will feel solid on handover day and let go later.
Final inspection and handover

The finished deck is inspected again in most places, and you should end up with the permit closed out, the manufacturer warranty registration for any composite or PVC surface, and a clear statement of what the builder warrants and for how long.

Watch for: A permit left open. An unclosed permit is a live problem on your property record and it is far easier for the builder to close it now than for you to chase them in three years.

Money

What does deck installation cost?

Most professionally built decks land between $8,000 and $30,000, and the spread is driven less by the decking you choose than by height, soil, footing count, stair runs and railing length. A tall deck on poor ground costs more than a larger one sitting near grade.

See the full deck installation cost guide — by material, size and region →

Deck sizing and planning tools → Rough out square footage and railing runs before you take quotes.

Straight answer

When deck installation is the wrong call

Everyone else ranking for this is paid when you say yes. Here's when you shouldn't.

The ground is already flat and close to the door. At near-grade a patio does the same job for less, needs no footings, no guards and usually no structure to maintain. Decks earn their cost when they get you across a drop.
Your house cannot take a ledger and you have not budgeted for a freestanding build. Some brick veneers, some stucco assemblies and some rim conditions cannot safely carry a ledger. The answer is a freestanding deck on its own posts — which is fine, but it needs more footings and more posts, and finding that out after you accepted a ledgered quote means a change order.
Your HOA or local zoning has not approved the footprint. People build first and ask second, and decks are large and visible. Get the approval before the footings, not after, because the remedy for an unapproved structure is removal at your expense.
You are chasing resale value on a short horizon. A deck is a use asset. If you will not personally use it for several seasons, the money is better spent on things buyers actually price.
You want a deck to solve a drainage problem. Building a platform over a wet corner hides the water, it does not move it. The water will still be against your foundation, now under something you cannot inspect.
The only quotes you can get are unpermitted. If nobody local will pull a permit for the work, that is information about the builders available to you, not about whether the permit is necessary. Wait and find someone who will.

Your options

Types of deck installation

Decking material

Composite, PVC, pressure-treated, cedar, redwood, tropical hardwood and aluminium all behave differently underfoot, in sun and over time. The material guides cover each on its own terms.

Head-to-head decisions

Composite versus wood, PVC versus composite, cedar versus pressure treated, covered versus open, ground level versus elevated — all resolved side by side.

Footprint and layout

Straight run, L-shaped, U-shaped, wraparound, multi-level and small-yard layouts, with what each does to the build.

Ledgered or freestanding

Attached to the house, or standing on its own posts. Your wall assembly often makes this decision for you rather than your budget doing it.

Covered or open

A roof over a deck changes it into a structure carrying roof and snow loads, which changes the posts, the footings and usually the permit.

Compare decks options side by side →

Straight answer

Can I do this myself?

A deck is one of very few home projects where a mistake is measured in ambulances rather than in money. Elevated decks that pull off houses fail suddenly and while loaded with people. If you build your own, the ledger connection and the guards are the two things not to learn on.

Reasonable to DIY

Deciding the footprint, the orientation and where the stairs should land
Reading your own jurisdiction's deck requirements before you take quotes — most building departments publish a homeowner deck handout
Choosing the decking material and finish
Building a genuinely ground-level platform that carries no guard and no stair, where local code does not require a permit — check first, because the threshold varies

Call a licensed pro

Anything attached to the house — the ledger detail and its flashing
Anything elevated enough to need guards
Footing design where frost, expansive clay or fill soil is involved
Stairs, which are the most-failed element at inspection
Any deck that will carry concentrated load such as a hot tub

Before you sign

What to check when hiring for deck installation

Who pulls the permit, and will the inspections be scheduled in your name?

The builder should. If they want you to pull it as a homeowner, the inspection record and the liability shift to you.
Walk me through your ledger detail — how is it fastened and how is it flashed?

The single best question on this page. A competent deck builder will answer it in detail and enjoy being asked. A vague answer is disqualifying.
What are the footings for my soil and frost conditions, and who determined that?

You want "the code requirement here is X and we confirmed it with the building department", not "we always do it this way".
Is this deck ledgered or freestanding, and why?

It should be a decision made about your wall assembly. If nobody has looked at how your house is built, nobody has made the decision.
How are the guard posts attached to the frame?

To the structure, not through the decking. This is a safety component and the attachment is the whole of it.
What is included for site restoration and spoil removal?

Footings generate a surprising volume of soil and a deck build wrecks the ground around it. Get it priced rather than discovered.
What do you warrant, for how long, and what is separately covered by the decking manufacturer?

These are two different warranties. The material warranty almost never covers the labour to replace the material, and the workmanship warranty is the one that matters for framing.

All decks hiring checklists →

Local pros

Deck Installation near you

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Related work

Often done at the same time

Deck Replacement

When there is already a deck there

Deck Railing Installation

The code-governed safety system

Deck Stairs Installation

The most-failed inspection item

Deck Inspection

Before you buy, or after a storm

All decks services →

FAQ

Deck Installation — questions people ask

Still have a question? Talk to our team →

Do I need a permit to build a deck?

Almost certainly, and you should assume yes until your building department tells you otherwise in writing. Many jurisdictions require a permit for any deck attached to a dwelling regardless of height, and set a low threshold for freestanding platforms. The permit buys you scheduled inspections of the footings, the ledger and the framing — an independent structural check by someone with no stake in the job. That is worth having even where it is optional.

How long does deck installation take?

The build itself is often a matter of days to a couple of weeks for a straightforward attached deck. The calendar is usually dominated by everything either side of it: permit review, an HOA approval cycle, utility locates, and waiting on inspection slots between the footing stage and the framing stage. Ask for a timeline that shows those gaps rather than just the build days, so you know what you are actually agreeing to.

What is a ledger board and why does everyone go on about it?

It is the board bolted to your house that an attached deck hangs from. It carries a large share of the deck's load, and failures at this connection are the classic cause of decks coming away from houses while occupied. Two things make it safe: fastening into real structure rather than into sheathing or a brick face, and flashing it so water cannot get trapped behind and rot the house framing it is bolted to. The second one is invisible after the build, which is why you ask to see it before the frame closes up.

How deep do the footings have to be?

That is set by your local code, your frost depth and your soil, and it genuinely varies enormously between jurisdictions — anyone quoting you a single national number is guessing. Your building department publishes the requirement, and it is one of the things the footing inspection checks. If a builder cannot tell you what the requirement is in your municipality, they have not looked it up.

Should the deck be attached to the house or freestanding?

It depends on what your wall is made of. Some assemblies — certain brick veneers, some stucco systems, some cantilevered floor conditions — cannot safely carry a ledger, and the correct answer there is a freestanding deck standing on its own posts and beams. It is not a downgrade, but it does need more footings and more posts, so it should be identified at quoting time rather than after the holes are dug.

Does the decking material change the structure underneath?

Sometimes, yes — which is why the material is not purely a look-and-feel decision. Different surface products have different requirements for how closely the joists beneath them must be spaced, particularly where boards run diagonally, and some expand and contract enough that gapping and fastening method matter. Settle the material before the frame is designed, not after, or you can end up paying to add framing.