Doors — Frames, Hardware & Fire-Rated Assemblies

Finishes

Door Gap Tolerances

Location	Standard	Fire-Rated
Hinge side	3 mm	3 mm max
Strike side	3 mm	3 mm max
Head (top)	3 mm	3 mm max
Bottom (hard floor)	10 mm	19 mm max
Bottom (carpet)	15–20 mm	19 mm max

Hinge Placement (2100 mm door)

Top hinge	175 mm from top
Bottom hinge	275 mm from bottom
Middle hinge	Centred between top & bottom
4th hinge	Doors > 2100 mm or > 45 kg

Lockset Functions

F01 Passage: Always unlocked — coat rooms, general
F76 Privacy: Thumbturn lock — washrooms, counselling
F82 Office: Inside thumbturn, key override
F84 Classroom: Key lock from corridor — lockdown capable
F86 Storeroom: Always locked, key entry, free egress

Fire-Rated Door Assemblies

Rating	Application	Max Glass
20 min	Corridor to offices/classrooms	6,452 cm²
45 min	1-hr fire separation doors	6,452 cm²
60 min	Stairwells, mech rooms	6,452 cm²
90 min	Major fire separations, exits	645 cm²

Rule: Door rating = ¾ of wall rating (OBC Table 3.1.8.4)

Critical Requirements

ULC/wH label must remain visible & legible — never paint over
Positive latching & self-closing mandatory
No field modifications without mfr. & listing agency approval
No hold-open devices unless connected to fire alarm
Smoke seals: continuous contact on all sides, zero gaps
HM frame grouting: cementitious only — never expanding foam

Hollow Metal Frames

Item	Value
Frame plumb tolerance	1.5 mm over full height
Frame level (head)	1.5 mm over full width
Diagonal square tolerance	2 mm max difference
Anchor spacing	600 mm max; min 3 per jamb
Spreader bar removal	After grout cured (24–48 hr)

Common Throat Sizes

92 mm: 2×4 wood stud + drywall
117 mm: 92 mm steel stud + drywall
143 mm: 2×6 / 152 mm steel stud + drywall
200–250 mm: CMU masonry walls

Accessibility (OBC 3.8 / AODA)

Requirement	Value
Clear opening width	860 mm min (at 90°)
Hardware height	900–1100 mm AFF
Max opening force	38 N (8.5 lbs)
Threshold max	13 mm (bevel if > 6 mm)
Pull-side clearance	600 mm beyond latch edge
Vestibule depth	1200 mm + door width min

Lever handles required — no round knobs
Power operators at all principal entrances & accessible WCs
Hold open min 5 sec; close at controlled speed

Hardware & Closers

Item	Spec
Lockset grade	BHMA Grade 1 (primary); Grade 2 (secondary)
Hinge type (w/ closer)	Ball-bearing butt hinges only
Std butt hinge size	4-1/2″ × 4-1/2″ (114 × 114 mm)
Closer sweep	5–7 sec (8–10 accessible)
Closer latch speed	1–2 sec
Exit devices	Required at > 100 occ. load (OBC 3.4.6.16)
Kick plate height	250 mm (push side)

Acoustic Doors (STC)

STC 30–33: Loud speech not intelligible (solid-core + seals)
STC 35–40: Loud speech barely audible (acoustic door)
STC 42–48: Most sounds inaudible (heavy acoustic door)
Light test: close door, lights off — if light leaks, sound leaks

Code References

OBC Part 3: Fire separations, exit requirements, assembly occupancy
OBC 3.8: Barrier-free design — door width, hardware, thresholds
OBC SB-9: Envelope flashing & exterior door weatherproofing
OBC Table 3.1.8.4: Door rating vs. wall rating
OFC (O. Reg. 213/07): Fire door labels, maintenance, inspection
AODA (O. Reg. 413/12): Accessibility standards
NFPA 80: Fire door inspection & maintenance
CAN/ULC-S104: Fire endurance tests for doors
ANSI/BHMA A156: Hardware standards (.1 hinges, .2 locks, .4 closers)
WDMA I.S.1A: Wood door gap tolerances

Safety — Do Not Forget

Fire-rated labels: Never remove, paint over, or obscure. Missing label = unrated door.
No foam in HM frames: Cementitious grout only for fire-rated assemblies.
No propping fire doors: Wedges, bricks, chairs = OFC violation. Use alarm-connected hold-opens.
Flashing sequence: Sill pan first, jamb over sill, head over jamb, WRB over head. Reversed lap = water in wall.
Low-expansion foam only for door/window frame gaps — standard foam bows frames.
NFPA 80 annual inspection: Every fire-rated door, every component, every year.

Pro Tips

Inspect HM doors at delivery against hardware schedule — wrong prep = 4–6 week replacement.
Verify throat sizes against actual wall conditions before ordering frames — trust nothing on drawings.
Force gauge every accessible door: 38 N max. Measure, don’t guess.
Dollar-bill test for weatherstripping: consistent resistance all around = proper seal.
Inspection kit: 1200 mm level, tape measure, force gauge, feeler gauges — catches 95% of deficiencies.