FRAMING
- Staples in PT lumber must be Stainless Steel R317.3
- Max stud height 12’
- WRB required on detached accessory buildings
- Tiny home: ≤ 400 sq ft (minus loft)
Attic Ventilation R806.2
- Min net free area 1/150 of the area of vented space
Clearances and Protection of Wood R317
- ≥ 12” to girders (18” if girders only) – ≥ 18” to bottom of joist or subfloor without joists
- PT fasteners: hot dipped galvi
- Hangers and clips must be ZMax or equivalent or must be protected with Bituthene when in contact with PT
- Sills in contact with concrete must be PT CRC R317.1.3
- Piers elevated ≥ 8” above the earth at the underfloor or PT post
- Concrete steps poured against wood:
- 26ga galvi flash installed to protect the wood, tight against the wall caulked with mastic
Access R408
Crawl Space:
- Through floor: ≥ 18” x 24”
- Through wall: ≥ 16” x 24” – unobstructed by pipes, ducts, etc.
- With equipment: ≥ 30” x 18” or large enough to remove the equipment
Attic: R807
- Opening allowing the largest component of the appliance and not < 22”x30”
Fire Blocking (combustible construction) R302.11
Provided to cut-off vertical and horizontal concealed draft openings and form a fire barrier between stories, and roof space
Locations (Concealed spaces of stud walls and partitions, including furred spaces and parallel rows of studs or staggered studs, as follows):
- Vertical at ceiling and floor levels
- Horizontal at intervals ≤ 10’
- Interconnections between concealed vertical/horizontal spaces (soffits, drop ceilings, and cove ceilings)
- Concealed spaces between stair stringers (top and bottom)
- Openings at vents, pipes, ducts, and wires at ceiling and floor level to resist the free passage of products of combustion
- Fire blocking cornices of 2-family dwelling at the line of dwelling unit separation
Materials (Fire blocking) R302.11.1
- 2” nominal lumber
- 2 layers of 1” nominal lumber
- 23/32” wood structural plywood
- 3/4” type 2-m particle board
- 1/2” gypsum
- 1/4” cement-based millboard
- Mineral wool or fiberglass
- Approved cellulose insulation
NOTCHING and BORING R602.6 and R502.8
Joists
Notching:
- ≤ 1/6 depth – ≤ 1/3 length
- No notch in middle 1/3
- ≤ ¼ depth of member at the end
Boring:
- ≤ 1/3
- < 2” from edges/holes/notches
Studs
Notching:
- Bearing: ≤ 25%
- Non-Bearing: ≤ 40%
Boring:
- Bearing: ≤ 40% with ≥ 5/8” edges
40-60% if double studs or stud shoes with ≥ 5/8” edges not > 2 successive studs - Non-Bearing: ≤ 60% with ≥ 5/8” edges
Plates
Bearing:
- ≤ 50%
- > 50% cut/notched = 16ga strap with 6-16d nails ≥ 6” past opening
Table R302.1(1)
- The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave overhang if fire blocking is provided from the wall top plate to the underside of the roof sheathing.
- The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the rake overhang where gable vent openings are not installed.