Key Takeaways:
- Raised deck = anything more than 24" above grade — triggers railing, stairs, and structural code requirements
- Footings go deeper than standard (4 ft+ in most of Canada to clear frost line)
- 42" railing required if deck floor is more than 71" above grade
- Typical use cases: walkout basement decks, second-story decks off the kitchen, decks on sloped lots
- Cost premium over ground-level: +$15–$35/sq ft for the structural framing
When You Need a Raised Deck
- Walkout basement — kitchen door is at first-floor level, ground drops away to a basement door
- Sloped lot — to get a level deck on uneven ground, one side rises
- Second-story access — deck off a master bedroom or upper kitchen
- Pool surround — to match an above-ground pool height
- View capture — sightlines over fences, gardens, treetops
Structural Considerations
| Element | Standard deck | Raised deck |
|---|---|---|
| Footings | 4 ft deep, 12" wide | 5–6 ft deep, 16"+ wide |
| Posts | 4×4 PT | 6×6 PT for tall posts |
| Beam size | 2×8 doubled | 2×10 or 2×12 doubled |
| Joist span | Up to 14' | Often 10' max with hangers |
| Lateral bracing | Sometimes | Always required above 6 ft |
| Stair stringers | 2×12 single | Doubled or triple for long flights |
The biggest hidden cost is lateral bracing — diagonal X-bracing between posts to prevent the deck from racking in wind.
Code Requirements (Canada)
- Railing 42" if deck floor over 71" above grade (NBC 9.8.7.1)
- Stair rise/run: 7"–7.875" rise, 9.25" run minimum
- Stair handrail: required on at least one side; both sides if stair > 1.1 m wide
- Guard infill: 4" sphere rule applies (no opening larger than 4")
- Footing depth: below frost line — varies 4–6 ft by region
Raised Deck Configurations
Walkout basement deck
Typically 8–12 ft above grade. Stairs to backyard. Often has a second deck below at the basement level (creating an "L"). We frame both as one engineered structure.
Second-story deck off kitchen
8–12 ft above grade, cantilevered if attached to the house, or post-supported if free-standing. The ledger flashing is critical — water penetration here is the #1 failure mode.
Pool deck surround (raised)
To match a 4–5 ft above-ground pool, the entire deck sits on posts. Independent of the pool wall (never attached).
Sloped-lot deck
Front of deck close to grade, back of deck 6–8 ft above as the ground drops. Different post lengths require lateral bracing on the tall side.
Cost Premium
| Height range | Add-on cost/sq ft |
|---|---|
| 24"–48" above grade | +$10–$20 |
| 48"–96" above grade | +$20–$35 |
| Over 96" (second-story) | +$30–$50 |
Plus stairs ($150–$300 per stringer + treads), ledger flashing ($400–$1,500), and engineering review for anything above 8 ft.
Common Mistakes We Fix
- Posts buried in concrete-filled holes without cones — posts heave with frost
- No lateral bracing on tall decks — the deck sways visibly in wind
- Inadequate ledger flashing — water gets behind the house cladding, rotting the rim joist
- Stair stringers too long without intermediate posts — bouncy steps
- Railing height of 36" on a 9-ft deck (needs 42")
Cost Examples (Installed)
| Project | Specs | Cost |
|---|---|---|
| 200 sq ft walkout deck (8' above grade) | Composite, stairs, railing | $18,000–$32,000 |
| 300 sq ft second-story deck (10' above) | PVC, glass railing, stairs | $36,000–$58,000 |
| 400 sq ft sloped-lot deck (max 8' high) | Cedar, lateral bracing | $32,000–$54,000 |
Request a raised deck quote or browse our composite decking and PVC decking options.
