Decks · Service

Deck inspection, starting at the house

A proper deck inspection begins at the connection to the building and works outward, because that is where decks fail. We match you with vetted local pros and tell you what a real report contains.

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In short

What is deck inspection?

A deck inspection is a structural assessment of an existing deck: the connection to the house, the footings and posts, the framing and its hardware, the guards, and the stairs. A useful one produces a written report you can act on, ranked by whether an item is dangerous now, deteriorating, or cosmetic. It usually takes an hour or two and most of it happens underneath the deck.

Triggers

Signs you need deck inspection

You are buying a house with a deck and want more than the paragraph a general home inspection gives it
You are selling, and want to know what a buyer's inspector is going to find before they find it
The deck came with the house and you have no idea whether it was ever permitted
A storm, a fallen limb or heavy snow has loaded the deck unusually
You are about to spend money on it and want to know whether to repair, resurface or replace
You are planning to put something heavy on it — a hot tub, a large planter arrangement, an outdoor kitchen
The deck is over about a couple of decades old and has never been looked at by anyone
You are about to host a large gathering on an elevated deck

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The job

How deck inspection actually works

The ledger, first and in detail

Where the deck meets the house, the inspector is looking at what the ledger is fastened to, what it is fastened with, whether it was flashed, and whether the house framing behind it is sound. This is checked first because a ledger failure takes the whole deck and everyone on it down at once, and because it is the defect a homeowner is least able to see.

Watch for: An inspection that never gets close to the house wall. If the report describes board condition and railing height but says nothing about the ledger, it has skipped the important part.
Underneath — footings, posts, beams, joists, hardware

The inspector goes under, or lifts boards if there is no access. They are probing for soft timber at joist ends and post bases, looking at how posts meet their footings, checking that the structural connectors are present, correct and not corroded, and looking for any sign the structure has moved.

Watch for: A report written from the top of the deck. Almost nothing that makes a deck unsafe is visible from up there.
Guards and stairs, tested rather than measured

Guards get pushed. Stairs get walked and their step heights compared. Both are checked against what your jurisdiction requires, which matters more than what looks normal — and both are where an old deck is most likely to be non-compliant, because requirements have tightened over the decades.

Watch for: An inspector who measures the guard height and never leans on it. Height is the easy half; whether the posts are anchored to anything is the half that matters.
The permit history question

A good inspector will ask, or check, whether the deck was ever permitted. An unpermitted deck is not automatically unsafe, but it means the structure has never been independently checked, and it is a live issue at resale and potentially at claim time.

Watch for: This being skipped. It is a public record in most places and it changes what the rest of the report means.
A written report, ranked by consequence

You want findings sorted into what makes the deck unsafe to use now, what will within a season or two, and what is cosmetic — with photographs. That structure is what lets you spend sensibly instead of doing everything or nothing.

Watch for: A verbal summary and a quote. Those are two different documents and you are paying for the first one.

Money

What does deck inspection cost?

A standalone deck inspection is commonly $150 to $500, depending on size, access and whether a written report with photographs is included. Free inspections offered by companies that build decks are a sales visit; useful, sometimes, but not the same product.

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

Straight answer

When deck inspection is the wrong call

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

You have already decided to replace the deck. Paying to be told a structure you are demolishing has problems is money you could put into the rebuild. Skip to a builder's assessment.
The deck is visibly failing. If posts are rotted through, the deck has separated from the house, or it moves when you walk on it, you do not need a report to tell you to stop using it. Fence it off and get a builder.
The "inspection" is free and offered by a company that sells decks. Not worthless, but understand what it is. Somebody whose income depends on the answer is not the person to settle a repair-or-replace question. Pay for an independent opinion if the number is large.
The deck is brand new and was permitted and inspected. It has just had a structural inspection by a building official with no financial interest. A second one within the warranty period rarely tells you anything new.
You want an inspection instead of a permit. They are not substitutes. An inspection tells you the condition of what exists; a permit and its inspections govern what is being built. An unpermitted deck with a clean inspection report is still unpermitted on the property record.
Nobody can physically get under it. A very low or fully enclosed deck cannot be properly inspected without lifting boards. An inspector who reports on it anyway is reporting on what they could see, which is the surface.

Before you sign

What to check when hiring for deck inspection

Will you get underneath the deck, and lift boards if you cannot?

If the answer is no, you are buying an opinion about the boards, not an assessment of the structure.
What will you tell me about the ledger connection specifically?

The defining question. An inspector who cannot describe what they look for at the ledger is not the right inspector.
Do you sell or perform deck repairs?

Not disqualifying, but you are entitled to know. If they do, weigh the recommendations accordingly, or get a second opinion before a large spend.
Do I get a written report with photographs?

A report you can hand to three builders for comparable quotes is worth several times a verbal summary.
Will findings be ranked by urgency?

Unranked findings force you to treat a splintered board and a failing ledger as the same decision.
Will you check whether the deck was permitted?

It is usually a public record, it takes minutes, and it changes what an absence of prior inspection means.

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Local pros

Deck Inspection near you

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Related work

Often done at the same time

Deck Repair

Acting on the report

Deck Replacement

When the report says start again

Deck Resurfacing

When the frame passes

Deck Maintenance

Keeping the next report short

All decks services →

FAQ

Deck Inspection — questions people ask

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What does a deck inspection actually check?

The structure, in order of consequence. The connection to the house comes first — what the ledger is bolted to, whether it was flashed, and whether the house framing behind it is sound. Then the footings, posts, beams, joists and the structural connectors holding them together, which means going underneath. Then the guards, which get physically pushed, and the stairs, whose step heights get compared. Surface condition is checked last because it is the least important thing about a deck.

Why is the ledger the first thing checked?

Because it is where decks fail catastrophically. An attached deck hangs a large share of its load off that connection, and when it lets go the whole platform comes away from the house with everyone standing on it. The two things that make it fail — fasteners into sheathing rather than structure, and no flashing so water has been rotting the house framing behind it for years — are both invisible from the deck surface. That combination, high consequence and low visibility, is exactly what an inspection is for.

Is a deck covered by a normal home inspection?

It gets looked at, but usually briefly and usually from above. A general home inspector is covering an entire property in a few hours and a deck is one item among hundreds; many will note obvious defects and recommend further evaluation rather than crawl underneath. On an older or elevated deck, or where a purchase decision turns on it, a dedicated deck inspection covers ground the general one does not have time for.

How much does a deck inspection cost?

A standalone independent inspection with a written report is typically a few hundred dollars, varying with the deck's size and how accessible the underside is. Free inspections are widely offered by companies that build and repair decks. Those are worth having and worth understanding: the person assessing your deck stands to be paid for the work they recommend. Where the recommendation is large, an independent second opinion is cheap insurance.

How often should a deck be inspected?

There is no universal interval, and anyone quoting one is inventing it. What is reasonable is to look at it yourself each spring — guards, stair steps, anything soft, anything that has moved — and to bring in a professional at the events that actually change the risk: buying or selling, unusual loading such as heavy snow or a fallen limb, before adding significant weight, and once a deck reaches an age where nobody currently living in the house knows how it was built.

I want to put a hot tub on my deck. Is this the right inspection?

It overlaps, but that assessment is its own thing — a filled tub with people in it is a large concentrated load in one spot, and the question is not whether the deck is in good condition but whether it was ever designed to carry that. Hot tub specialists handle it directly at our deck assessment for spas page. Get that done before you buy the tub, not after it is on the driveway.