A deck usually becomes unsafe at three points: the support posts and the footings under them, the ledger board where the deck is bolted to the house, and the railing and stair connections. Rotted posts set into soil, ledgers fastened with no flashing behind the siding, and joists carried on nails instead of metal hangers are the conditions we find. All three are repairable. Posts are replaced on new concrete footings, ledgers are re-bolted and flashed, and joists and stair stringers are tied with hangers and brackets.
How to tell if a deck is unsafe
Homeowners usually call about a board. What the board is telling you is further down. These are the conditions that turn a tired deck into an unsafe one, and each has come out of an inspection on a job called in for something else:
- The deck moves when you walk on it. Lateral movement means the ledger, the bracing or the post connections are no longer doing their job. Wind bracing is routinely missing after someone has worked under a deck and never put it back.
- Posts are soft at the base. A post set directly into soil, or sitting on a footing the ground has washed away from, rots from the bottom up. We have dug out posts where the footing had deteriorated along with them.
- Railing sections give when you lean on them. Loose pickets, a top rail pulling away from its posts, or a bench built into the rail as the only guard — an arrangement that does not meet current safety code.
- The stairs bounce, the landing has tilted, or there is no handrail at all. An uneven staircase landing means the ground under it has moved. We have repaired deck stairways that had no handrail on them whatsoever.
- Water stains inside the house, near the deck. Damage to interior drywall, window trim and casing at a wall the deck attaches to is a ledger flashing problem until proven otherwise.
If two or more of those are true, stop using the stairs and call. The inspection tells you which of them are cosmetic and which are structural, and those are different jobs with different answers.
Why deck posts and footings fail, and how they are replaced
Post failure is the single most common structural repair we are called out for on a deck. The post rots at grade, or the concrete footing under it deteriorates and lets the post settle, or both at once. On one job seven support posts under a deck had deteriorated and an eighth corner post had to be added where there had never been one.
Replacing a deck post is not a matter of pulling one out and dropping another in. The deck has to be held up while it happens. The sequence we use is fixed:
- Install temporary support on both sides of each post being replaced so the beam above never loses its bearing.
- Excavate around the post and its footing, then disconnect and remove both and haul them away. Where a post has been encased in a slab or patio, the concrete is cut back on two sides and re-poured when the work is done.
- Pour a new footing — typically 24 x 24 inches, minimum 3500 PSI concrete — sized and set below the depth the ground moves at.
- Set a new 6x6 pressure-treated pine post on metal post bases and anchors, and bolt it to the beam above rather than relying on toe-nailing.
- Backfill and grade the ground to fall away from the post, so surface water is not being delivered to the base of the thing you just replaced.
- Reinstall the wind bracing and re-secure anything that came off to get access.
Grading matters more than people expect. Water pooling at the base of deck posts is usually also pooling against the house, which is a foundation, grading and crawl space problem as much as a deck one.
Deck ledger board attachment and the leak it hides
The ledger is the board bolted to the house that carries one whole side of the deck. It is also the single most likely place for water to get into your wall, and the two problems are usually found together.
On one call the complaint was water entering the house where the deck meets the siding, showing as damage to window trim, casing and drywall inside. Behind the siding there was no flashing at all above the ledger board and joists, so every rain ran down the wall and into the framing. The fix meant taking up the deck floor planks, disconnecting the siding along the deck, installing metal flashing under the siding and above the ledger and joists, sealing it with polyurethane caulk, and reinstalling the planks with galvanized screws.
The other half of a ledger repair is the fastening. On a two-level deck rebuild the ledger board was re-bolted with bolts set in a zigzag pattern no more than twelve inches apart — that pattern is what keeps the board from splitting along a single line of fasteners and letting the deck drop away from the house.
If the siding has to come off to reach the ledger, it goes back properly — see siding repair and replacement. Interior damage from a ledger leak is handled as drywall and ceiling repair once the water is stopped.
Deck joists, beams and stair stringers: the connections that matter
Once the posts and the ledger are sound, the next question is whether the framing between them is actually connected. Older decks and porches were often built with joists and stringers face-nailed into a beam or a rim board. Nails in end grain pull out. Metal hangers do not.
On a front porch we were called to for a patio door, the inspection found the porch joists and stringers loose and in need of metal hangers — that was not what the homeowner called about, and it was the most important thing on the property. On a two-level deck rebuild the existing joists and beams were secured and joist hangers and brackets added throughout before any new decking went down.
What gets checked on the frame
- Joist-to-beam and joist-to-ledger connections, and whether a hanger is present and fully nailed off.
- Beam-to-post connections, and whether the post is bolted to the beam or simply sitting under it.
- Stair stringer attachment at the top and the bearing at the bottom.
- Rot at the cut ends of joists, which is where water sits and where a visual check from the ground will not reach.
On larger rebuilds a structural engineer inspects the footings, posts, beams and joists before we price the work, and specifies underpinning if the inspection calls for it.
Deck railing, pickets and stair repair that meets code
Guards and handrails are the part of a deck that a person puts their whole weight against without thinking about it, so this is where current code is least forgiving and where old decks most often fall short.
- Loose pickets and a failing top rail
- Common on older front porches alongside decayed corner posts. Where the top rail itself has gone, it is replaced — a 2x6 pressure-treated pine top rail is our standard — and the pickets re-secured to it.
- A bench used as the guard
- We have found decks where a built-in bench and rail arrangement along one side was doing the work of a guard rail. It does not meet current safety code and it gets rebuilt as a proper guard.
- Stairs with no handrail
- Added where missing, anchored into the stringers and posts rather than into decking.
- An uneven or settled stair landing
- The staircase is leveled and a proper concrete landing poured underneath it — on one rebuild a 4 ft by 8 ft landing. See concrete, walkway and step repair for how that side of the work is done.
Rotted deck boards, loose planks and deck refinishing
The cosmetic layer is real work too, and it is often how we get onto a deck in the first place. The rule we follow is that boards do not get replaced until the framing under them has been looked at.
On one deck we removed five to ten boards at the end of the run purely to open the framing, inspected it, and reported to the homeowner before pricing further repair. On another, fifteen planks had failed and the stairway had no handrails — the planks were the least of it. Worn boards are replaced in kind with 2x6 pressure-treated pine, screwed rather than nailed, and every remaining floor board is re-secured with its nails set.
Refinishing follows the same order. Decks get cleaned with a moss, mold and mildew remover and a multi-surface cleaner, power washed, then sealed or finished with a solid deck stain; railings are usually painted rather than stained where the previous finish has faded unevenly. A mildewed deck with faded railing is a two-stage job, not a single coat. Larger exterior painting work is covered under interior and exterior painting.
Wood lattice under a deck is replaced with PVC lattice, which does not rot and never needs repainting. Rotted trim, fascia and structural wood elsewhere on the house is handled as rotted wood and trim repair.
Porch repair: columns, decking, joists and settlement
A covered porch is a deck carrying a roof, and that changes the stakes. The corner posts are not just guard posts — they are columns holding the roof up.
On one property the front porch had loose pickets, a settled deck and decayed corner posts; the inspection confirmed two of the corner posts were decayed through. On another, the front porch decking and railings had deteriorated and the joists and stringers underneath were loose. Both were repairable, and in both cases the structural items were the ones the homeowner had not mentioned.
Where a porch is cracking rather than rotting, the question changes from carpentry to settlement. We brought a structural engineer onto a front porch with continuous horizontal cracking along the joint between the porch floor slab and the concrete wall on three sides. He attributed it to slight settlement of the concrete curtain wall, and assessed a separate gap between the slab and the main building as cosmetic. With no access under the slab, the pier and footing condition had to be verified by digging test pits about thirty inches deep. If footings were there, the cracks were cosmetic and repairable; if not, the foundation had to be underpinned. Verify, then decide.
Do you need a permit for deck repair in Virginia?
It depends entirely on whether the work is structural. Replacing worn decking boards, re-securing loose planks, replacing a top rail, cleaning and refinishing — none of that requires a permit.
Structural deck work does. Replacing support posts and footings, re-bolting or replacing a ledger board, rebuilding framing, rebuilding stairs, or building a new deck or an addition-level structure is permitted work in the jurisdictions we serve. Where a permit is required we pull and process it ourselves, the work is performed according to the Virginia building code and to approved plans and structural details where the job has them, and the framing is inspected before it is covered. Permit and permit processing fees are written into the contract.
On larger jobs the sequence is plans, permit, framing inspection, then finish work, and where an engineer is involved the framing is built to the engineering plans rather than to a rule of thumb.
What deck and porch repair costs, and how we price it
We do not quote deck repair by phone and we do not publish prices. Two decks that look the same from the yard can be completely different jobs: one needs boards, the other has eight failed posts, an unflashed ledger and a settled landing. Until someone has been under the deck, any number is a guess.
An estimator comes to the property, gets under the structure where there is access, and gives you a written price for the work in front of him before anything begins. Where the inspection turns up something that needs an engineer, we say so rather than price around it. Sam & Sons Services has been doing this work in Northern Virginia since 1999 under Virginia DPOR license #2705070610, and you can reach us at (703) 256-8080.
