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Floors and Roof Framing in Ontario (2026): I-Joists or Floor Trusses, Bouncy and Squeaky Floors, Roof Truss Cost, Trusses or Rafters for Cathedral Ceilings
Framing & Building SystemsFloors and roofs
Floors and Roofs: Engineered Wood Is Engineered Until Somebody Cuts It
Engineered floors, bouncy floors, roof trusses and cathedral ceilings. Ontario, October 2026.
Many new Ontario houses stand on engineered floors and under factory-built trusses. Both are designed by somebody with software and a stamp, and both are ruined by somebody with a saw. The floor and roof are where the plumber, the electrician and the heating contractor all want to run something, so the plan for the holes has to exist before the joists arrive.
The numbers
$4 to $9per lineal foot, I-joists by depth and series (thin data)
$3,750 to $11,300simple gable truss package, our derived estimate
$900 to $1,400half a day of boom truck and crew to set the trusses
$10,000 to $30,000whole roof structure per house, a Canadian finance guide
On our houses, the floors and roof are wood
On the ICF houses we build, the floors are engineered I-joists bearing on the ICF walls and the roof is wood trusses set on top of them. The ICF part of the house is concrete and foam; everything that spans is engineered wood. So the floor layout and the truss drawings land on our desk on every job.
Engineered I-joists are accepted when they are installed to their CCMC evaluation and the maker's instructions, and that includes the maker's hole charts. The chart says where a hole may go, how big, and how close to a bearing. Anything outside it is a call to the supplier, not a guess with a hole saw. Nobody cuts, notches or drills a truss or an engineered joist except as the manufacturer allows. I-joists or floor trusses covers spans, ducts and stiffness, and plumbing an ICF house and wiring an ICF house show where the services go.
Trusses: the plant designs them, an engineer seals them
Truss shop drawings come from the truss supplier, sealed and signed by a Professional Engineer, and building departments ask for them. The truss designer marks where individual members need restraint, the building designer specifies the permanent bracing and anchorage, and the framer installs the temporary bracing. Three parties, three jobs. If your quote does not say who does which, ask.
Trusses are priced by span and shape. One Canadian calculator site puts delivered prefab gable trusses at about $5.00 to $7.50 a foot of span and another at about $9. Our derived example: a 30 to 36 ft span at $5 to $9 a foot, times 25 to 35 trusses, is about $3,750 to $11,300 for a simple gable roof before girders, hips and delivery. A hip roof runs about 15 percent more and a gambrel about 25 percent more than a gable (a Canadian calculator site). Then the trusses have to get up there: roof truss cost has the crane and boom truck.
Bouncy floors and cathedral ceilings
A floor can meet the code and still feel like a trampoline. Deeper joists, closer spacing, a glued and screwed subfloor, strapping and blocking all stiffen it, and they are cheap on paper and expensive after the drywall. Bouncy and squeaky floors sorts annoying from structural.
A vaulted ceiling means scissor trusses or stick-framed rafters on a structural ridge beam, and the insulation and venting have to be worked out at the same time. We found no Ontario price for rafters per square foot; it is quoted per job. Trusses, rafters and cathedral ceilings covers the trade-offs. Ceiling cracks in the first winter are often truss uplift, not a failing roof.
The guides
I-joists or floor trusses?
Dimensional joists, I-joists and open-web trusses: spans, ducts and drains, stiffness, the hole rules, cost per lineal foot (thin, and we say so), and what suits an ICF basement and a radiant floor.
Bouncy and squeaky floors
Why floors bounce and squeak, how a stiffer floor is designed, fixes in an existing house, and when it is a structural problem rather than an annoyance.
Roof truss cost
How a truss plant prices, span and pitch, girders and hips, a simple gable worked out, the crane or boom truck, sealed shop drawings and who braces what.
Trusses, rafters and cathedral ceilings
Manufactured trusses against stick-framed rafters, scissor trusses, structural ridge beams, attic trusses, insulating and venting a vaulted ceiling, and the cost drivers.
Truss uplift
Already on the site: why the bottom chord rises in winter and how drywall clips and floating corners deal with it.
Roofing
Already on the site: the whole section on what goes on top of the trusses once they are sheathed.
Deck framing
Already on the site: deck joists and beams, which are outside and carry different loads.
Plumbing an ICF house
Already on the site: running the drains and supply lines in an ICF house.
The home heating guide
Already on the site: ducts and radiant heat, both of which have to fit around the floor framing.
The calculators
Free, on the same October 2026 prices these pages use. A budget and a better question, not a quote.
House framing cost calculator
The framing by floor area and shape, with the truss package and the crane or boom truck estimated.
Building system cost comparison
The same house, wood frame against SIP, ICF, log, timber frame and modular, at Level 4.
Custom home building calculator
Already on the site: the floors and roof inside the whole house budget.
What it costs, October 2026
| Item | Ontario range | Level | Source and notes |
|---|---|---|---|
| I-joists, per lineal foot | $4 to $9 | Level 1 | by depth and series; a Canadian calculator site, no named data |
| Whole-house engineered floor or open-web truss package | no price found | Level 1 | quoted per job from your layout |
| Subfloor replacement in a renovation | adds $2 to $5 per sq ft | installed | a GTA contractor |
| Prefab gable trusses, delivered, per foot of span | $5.00 to $7.50; about $9 | Level 1 | two Canadian calculator sites |
| Simple gable truss package, 25 to 35 trusses | $3,750 to $11,300 | Level 1 | our estimate, before girders, hips and delivery |
| Hip roof / gambrel roof | about 15 / 25 percent more than gable | Level 1 | a Canadian calculator site |
| Whole roof structure, per house | $10,000 to $30,000 | Level 2 | a Canadian finance guide |
| Crane, per day | $700 to $1,500 | equipment | a Hamilton crane company |
| Boom truck and crew, half day, 21-truss house | $900 to $1,400 | equipment | a calculator site |
| Stick-framed rafters or cathedral roof, per sq ft | no price found | – | quoted per job |
Worked example, our estimate: 30 ft span x $5 x 25 trusses = $3,750; 36 ft span x $9 x 35 trusses = $11,340, call it $11,300. Add a half day of boom truck at $900 to $1,400 and the simple gable is about $4,650 to $12,700 lifted onto the walls, before girders, hips, delivery and the framer's labour.
Why Ontario prices are all over the map: the suppliers, contractors and published price guides we checked for this page quoted very different prices for the same roof. Trusses ran $5.00 to $7.50 a foot of span from one Canadian calculator site and about $9 from another, while a Canadian finance guide put the whole roof structure at $10,000 to $30,000. A Hamilton crane company charged $700 to $1,500 a day, and a half-day boom truck ran $900 to $1,400. Span, pitch, hips, girders, delivery and whether labour is in explain most of it. Budget the top of our derived example, about $11,300 for a simple gable, and get two or three quotes on the same written scope.
Rules of thumb worth keeping
- Plan the holes before the floor arrives. Ducts, drains and wires get a route on paper, checked against the maker's hole chart. I-joists or floor trusses.
- Never cut, notch or drill a truss or engineered joist except as the maker allows. Tell every trade on day one.
- Keep the sealed truss drawings with the permit papers. The inspector will want them, and so will the next owner.
- Ask who does the permanent bracing. The truss designer marks it, the building designer specifies it, the framer installs it.
- Book the crane or boom truck with the trusses. And check the lot can take a truck. Roof truss cost.
Have quotes in hand? Let a builder read them first
For $99 I read up to three framing, truss, beam, SIP, log, timber frame or modular quotes, or one quote plus your plans, and put them on one grid at the same level of completion: the measured area, the lumber package, trusses and engineered floor, beams, sheathing and wraps, windows, the crane, the engineering and the permit. You get a written answer on what each one left out, in dollars, and which one I would sign.
There is no contractor network behind it, we do not send your plans to suppliers, and nobody pays us a referral fee. We are a builder, not a framing subcontractor, a SIP factory, a log company or a modular dealer. Outside our own area I will tell you honestly whether I know anyone.
Questions people ask
How much do roof trusses cost in Ontario?
For a simple gable roof our derived estimate is about $3,750 to $11,300 for 25 to 35 trusses on a 30 to 36 ft span, before girders, hips and delivery. Hips add about 15 percent. Roof truss cost.
Can the plumber cut a hole in an I-joist?
Only where the maker's hole chart allows, at the size it allows. Engineered joists are accepted when installed to their CCMC evaluation and the maker's instructions. If it is outside the chart, call the supplier before anyone picks up a saw.
Why does my new floor bounce?
Often the floor meets the minimum but was not designed for stiffness: span, depth, spacing and the subfloor all matter. If it is cracking, sagging or moving, keep weight off it and get an engineer or qualified contractor now. Bouncy and squeaky floors.
Trusses or rafters for a vaulted ceiling?
Scissor trusses are the usual way and are designed by the truss plant. Rafters on a structural ridge beam give a cleaner vault and need the ridge engineered. Trusses, rafters and cathedral ceilings.
Are truss shop drawings really sealed by an engineer?
Yes. They come from the truss supplier, sealed and signed by a Professional Engineer, and building departments ask for them.
Price the roof and the crane together
The house framing cost calculator adds a truss package and a crane or boom truck to the framing at October 2026 numbers. If a truss plant or framer has quoted already, send up to three quotes to the $99 review.
Sources and further reading
- Residential building permit requirements (Clarington): truss shop drawings sealed by a Professional Engineer, and when professional design is needed outside Part 9.
- Trusses and engineered wood products declaration (Arran-Elderslie): how a municipality accepts trusses and engineered floor joists, and who is responsible for bracing and anchorage.
- CMHC Builders Series: drywall application: why trusses lift in the first winter and how drywall clips and floating corners handle it.
