Loose boards, a wobbly railing, stairs that sink on one side. Most Ottawa decks fail a little at a time and for the same reason. We repair decks across Ottawa and Gatineau, and because we build decks for a living we will tell you honestly whether yours is worth repairing at all.
Freeze and thaw is doing most of this
What damages a deck here is not the cold, it is the number of times a year water gets into something, freezes, expands and thaws again. Every pass levers at a gap: a screw hole, a split in end grain, the seam between a ledger and the wall. It forms ice under a shallow footing and lifts the post, which is why one corner sits proud and the stairs stop meeting the ground squarely. Rot is not really a wood problem. It is a drying problem.
Rot starts at the ledger and the post bases
The ledger is the board bolted to your house carrying one whole edge of the deck. Without proper flashing, water runs down the wall and sits in the joint behind it: the wood softens, fasteners lose their grip, and there is no sign until the day it lets go. Ledger failure is the most common cause of deck collapse and it goes all at once, so we pull trim or siding to look properly. The post bases are the other one. End grain wicks water upward, so a post set into soil, or flat on a pier with no standoff bracket, rots from inside its bottom 100 millimetres while the top looks immaculate.
Joists, beams, footings and fasteners
Frame damage is usually localised. Joist ends rot first, because that is where water sits against the ledger or the beam, and where the rest of the joist is sound the honest repair is to sister a new member alongside it. Where several consecutive joists are gone, the frame comes out. Beams are less forgiving: one carries several joists, so replacing it means supporting the deck above. Heaved posts get their footing re-set below the frost line.
Plenty of “the deck is loose” calls are not rot at all. Nails back out of framing as wood cycles wet and dry, and joist hangers put up with roofing nails rather than the structural connector nails they are rated for never carried their design load. Modern pressure-treated lumber is also far more corrosive to ordinary steel, so plain fasteners corrode from inside the hole outward: that rusty streak is the fastener disappearing. Hot-dip galvanized or stainless is the remedy.
Boards, and the honest problem with matching
Cracked, cupped, splintering or soft boards get replaced in pressure-treated, cedar, composite or PVC, matched to what is already down. New material will not match aged material: new pressure-treated beside eight-year-old reads as a patch for a season or two, cedar silvers at different rates with exposure, and composite colour lines get discontinued or shift between runs. So we lift sound boards from somewhere nobody looks and put the new material there, replace a complete field so the difference reads as deliberate, or on wood re-stain the whole deck afterwards.
Railings and stairs meet the code as it is now
Replace a guard and the new one is built to the Ontario Building Code in force today, not the rules the deck was built under. Guards are required wherever there is more than 600 millimetres of difference in elevation between the walking surface and the surface beside it. An exterior guard serving a house must be at least 900 millimetres high where that surface is not more than 1,800 millimetres above finished ground, and 1,070 above that. Openings must stop a 100 millimetre sphere, and nothing between 140 and 900 millimetres may be shaped so a child can climb it.
Stairs serving a house are private stairs: rise between 125 and 200 millimetres, run between 255 and 355, risers uniform within 5 millimetres between adjacent steps and 10 across the flight, at least 860 millimetres wide, with a handrail on more than three risers set 865 to 1,070 millimetres above the nosings. That uniformity clause is the one people trip on, literally. Source: O. Reg. 332/12, Building Code, Division B, Section 9.8
Stripping and re-staining
A film-forming stain sits on top of the wood, so moisture arriving from below or through end grain lifts the film from underneath and the deck peels in sheets rather than fading evenly. A fresh coat over a failing one buys a season at most. Restoration is a sequence: clean, strip, brighten the wood back toward its natural pH, sand, refasten anything loose, then stain onto bare dry wood at a curing temperature.
Repair or replace, and how we decide
A deck with a sound frame is nearly always worth repairing, so we check the frame first: the ledger and its flashing, the post bases, the joist ends, the beam bearings and the footings. If those are good we quote the repair even when the deck looks terrible, because appearance is the cheap part to fix. Replacement is the better call when several consecutive joists or a beam bearing are gone, when the footings never went below the frost line, or when rot has carried from the ledger into the house wall. There is a non-structural case too: if the deck is the wrong size, height or place for how you use the yard, repairing it well just preserves a layout you do not like.
When a repair needs a permit
Like-for-like surface work is maintenance. Rebuilding the structure, changing the footprint or raising the height is not, and that is where a repair becomes a build. A deck attached or adjacent to the house needs a City of Ottawa building permit once its walking surface is more than 600 millimetres above the adjacent grade, whatever its area; any deck providing principal access needs one regardless of area; and a freestanding deck needs one once it is both over 10 square metres and more than 600 millimetres up. Source: City of Ottawa: Decks
On doing it yourself: swapping a cracked board is a weekend job, but anything touching a railing post, a stringer, a joist or the ledger is not.
