Framing a second storey wall is the same basic technique as framing a first floor wall — but with two complications: you're working at height, and the walls below have to support whatever you build above. For new builds and additions, second storey framing follows engineered drawings showing wall heights, stud spacing, header sizes, and tie-down requirements.

This guide covers a typical 8 ft tall second storey exterior wall, 2×6 framing, on top of a finished subfloor and rim joist. It assumes engineered drawings are in hand and a permit has been pulled.

Before you start

Three things to settle:

1. Wind loading is a real factor on second storey walls. Second storey exterior walls face higher wind loads than first floor walls. Building Code typically requires shear walls (plywood-sheathed wall sections), hold-downs at corners, and connections engineered for uplift. Engineered drawings spec these — don't simplify.

2. Bottom plate must align with wall below. Second storey walls must sit directly above first floor walls (load path) for non-engineered cases. Offset walls require beam transfer below — engineered work. Verify your drawing.

3. Sheathing on the deck before standing the wall. Easier to apply structural sheathing (plywood/OSB) to the wall while it's lying flat on the second floor deck. Standing pre-sheathed walls is heavier but eliminates fall hazard from sheathing at height.

What you'll need

Tools

Circular saw or mitre saw
Drill with bits and driver
Hammer or framing nailer
Tape measure
Level (4-foot)
Speed square or framing square
Chalk line
Stud finder
Safety glasses, hearing protection, fall harness (working at height)

Materials

2×6 lumber for studs and plates (kiln-dried, exterior wall standard)
16d framing nails or 3-inch construction screws
Headers and jack/king studs for openings
Hold-downs (Simpson HDU or equivalent, per engineer)
Anchors for bottom plate to floor structure
Sheathing (OSB or plywood, 7/16 inch or 1/2 inch)
Sheathing nails/staples

Pre-sheathe walls flat on the deck

Apply OSB sheathing to the wall while it's lying flat on the second floor deck. Easier, faster, and avoids fall hazard from working at height.

Pre-sheathed walls are heavy — a typical 16 ft long pre-sheathed wall weighs 600-900 lbs. Plan for 3-4 people or a wall jack to stand it.

Step-by-step instructions

Verify the deck is square and level

Before building walls, confirm the second floor deck (subfloor + rim joists) is square and level. Diagonal measurements should be equal.

Out-of-square deck = out-of-square walls = roof problems later.

Snap chalk lines for wall locations

On the deck, snap chalk lines marking the inside edge of every wall (interior side of bottom plate).

Reference engineered drawings for wall locations.

Cut bottom plate, top plate, and studs

Bottom plate and top plate: 2×6 cut to wall length.

Studs: cut to (wall height) − (bottom plate 1.5) − (top plate 1.5) − (cap plate 1.5 if used). For 8 ft wall with double top plate: 92.625 inches (US), 92.5 inches (CDN spec).

Cut all studs at once for consistency.

Lay out studs on plates

On bottom plate, mark stud locations: end studs flush with wall ends, then 16 inches on-centre.

Mark king and jack stud locations at all door/window openings per drawings.

Transfer marks to top plate.

Assemble wall flat on the deck

Lay studs between bottom and top plates at marks.

Drive nails or screws through plates into stud ends. 2 fasteners per joint minimum.

Install headers, jack studs, king studs, and cripple studs at every opening per drawings.

Apply sheathing to the wall (flat on deck)

Lay OSB or plywood sheathing on top of the wall.

Align so sheathing edges meet on a stud or plate.

Nail at edges per drawings (typically 6 inches at edges, 12 inches at intermediate studs).

Cut openings for windows/doors before nailing all the way.

Stand the wall up

With 3-4 people OR a wall jack: lift the wall up. Walk it up vertical, slide it onto the chalk line.

Drive nails/screws through bottom plate into rim joists below the deck.

Plumb the wall (vertical) using a level. Brace temporarily with diagonal 2×4s nailed to deck and wall.

Install hold-downs and connections per drawings

Hold-downs (Simpson HDU or equivalent) at corners and shear walls — anchor to engineered hardware in the floor below.

Verify all engineered connections per drawings before drywall stage.

Inspector will verify these at framing inspection.

Add second top plate (cap plate)

Add a second top plate (called the 'cap plate' or 'double top plate') over the first top plate — overlapping joints and intersections with adjacent walls.

Nail every 12-16 inches to lock walls together at the top.

Verify wall is plumb and braced

Check plumb (vertical) and string-line straight (no bow side-to-side).

Add temporary diagonal braces from wall to floor to maintain plumb until adjacent walls and roof framing tie everything together.

Common mistakes that cost you

Wall not aligned with wall below. Second floor wall must sit on first floor wall (load path). Offset = engineered work.
Skipping shear wall sheathing. Wind and earthquake loading need shear resistance. Sheathing nailing schedule is critical.
No hold-downs at corners. Wind uplift can lift a wall. Hold-downs required per engineer.
Pre-cut studs wrong length. Even 1/4 inch off times 16 ft becomes a major problem. Verify stud length on first cut, then mass-produce.
No fall protection at height. Working on second floor edges requires harness and tied-off lanyard per Ontario WSPS guidelines.

Frequently asked questions

Can I add a second storey to my existing one-storey house?

Sometimes. Existing foundation, walls, and floor structure must be assessed by an engineer for capacity to carry an added storey.

Most early-1900s homes require foundation reinforcement; mid-century homes often need wall reinforcement.

Cost for a second storey addition in Ottawa varies widely with scope — foundation and wall reinforcement, span, finish level, and whether you remain in the home during construction all drive the budget.

How tall can a second storey wall be?

Standard residential: 8 ft (most common) or 9 ft (high ceilings).

Above 9 ft: pre-cut studs become custom orders, longer headers needed, framing becomes more complex.

Engineered drawings should specify wall height per local code.

Do I need a permit?

Yes — second storey framing requires building permit in Ontario.

Drawings stamped by engineer or BCIN designer.

Permit fees scale with project size, so a second storey addition costs more than the City of Ottawa $117 minimum that applies to small jobs.

When to call us instead

Second storey additions are major structural projects. Our team handles design, engineering, permits, and execution as a fixed-price scope.

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