NOTE Light-frame wood construction is a repetitive-member system: many small, closely spaced members (studs, joists, rafters) share load through sheathing and blocking rather than relying on a few large members. (1.1.1)

NOTE The system serves IBC Type III and Type V buildings, including residential, low-rise commercial, and light industrial occupancies, and applies to both platform-frame and balloon-frame assemblies. (1.1.2)

NOTE Engineered wood headers and beams (LVL, PSL) used as drop-in substitutes for dimensional headers are addressed here only at the interface; the engineered product itself is specified with its product Standard. (1.1.6)

NOTE Heavy timber and mass timber structural systems (glulam frames, CLT panels, NLT, DLT) are not part of this Standard. (1.2.1)

NOTE Mass timber and other large-section systems behave and are detailed differently from repetitive light framing; see Mass Timber. (1.2.2)

NOTE Cold-formed steel studs, joists, and track are not part of this Standard; see Cold Formed Metal Framing. (1.2.3)

NOTE Non-structural rough carpentry — blocking, nailers, grounds, wood curbs, rough bucks, sleepers, and furring that carries no structural load — is not part of this Standard; see Rough Carpentry. (1.2.4)

NOTE Finish trim, millwork, and architectural woodwork are not part of this Standard; see Finish Carpentry. (1.2.5)

NOTE Glued laminated timber, structural composite lumber, and wood I-joists are specified with the engineered wood product being used, except where used solely as a dimensional-lumber substitute header as noted above. (1.2.6)

NOTE Gypsum sheathing and the fire-resistance rating of wall, floor, and roof assemblies are not part of this Standard; see Gypsum Board Assemblies. (1.2.7)

NOTE Temporary wood framing that supports fresh concrete is concrete formwork, not structural framing; see Concrete Formwork. (1.2.8)

NOTE The adopted building code edition for the project jurisdiction governs over the editions listed below where the jurisdiction has amended or pinned a different edition. (2.2.1)

NOTE The grade stamp is the legal record that the member carries the design values used in the structural calculations; an unstamped member has no assigned design value and is unenforceable. (4.1.2)

NOTE The prescriptive path of IBC Section 2308 is capped at three stories above grade plane, a maximum bearing-wall height of 10 ft, and is not permitted in Seismic Design Category E or F without engineering. Commercial projects routinely exceed these caps, which forces full NDS engineering — confirm the path before relying on prescriptive tables. (4.2.3)

NOTE Omitting required special inspection is a common cause of failed inspections at certificate of occupancy, because shear-wall nailing cannot be verified once sheathing and finishes are closed in. (4.3.3)

NOTE Green or surfaced-green (S-GRN) lumber installed in enclosed framing shrinks as it dries in service, causing nail pops, drywall cracking, and loosened connections. KD-19 lumber is treated as dry-service, so the wet-service moisture factor CM = 1.0 applies (IBC Section 2303.1.5). (5.1.2)

NOTE The boundary between above-ground and ground-contact retention is set by AWPA U1 use categories: UC3B for above-ground exterior, UC4A for general ground contact (including sill plates on slabs above grade), and UC4B for severe or critical ground contact. Specifying the wrong category lets the contractor default to the cheapest retention, which may not be code-compliant for the application. (5.2.3)

NOTE Modern waterborne preservatives (ACQ, CA-C, MCA) are more corrosive to steel than legacy CCA; using under-rated fasteners with them causes accelerated connector failure. See Dampproofing where a moisture break is also detailed at the sill. (5.2.5)

NOTE Species and grade together fix the design values. Calling for "No. 2 or Better" without a species is meaningless, because No. 2 design values differ dramatically between species groups — Southern Pine No. 2 2x10 has a tabulated Fb of 1500 psi while Spruce-Pine-Fir No. 2 2x10 is 875 psi. Both pieces of information are mandatory. (6.1.2)

NOTE The NDS tabulated value (for example No. 2 Douglas Fir-Larch 2x10 Fb = 900 psi from NDS Supplement Table 4A) must be adjusted by the applicable factors — load duration CD, wet service CM, temperature Ct, size CF, incising Ci, repetitive member Cr, and others — before it becomes the allowable design value. Using raw table values overstates capacity. Cite NDS Supplement Tables 4A and 4B for the specific value; never invent a design value. (6.1.5)

NOTE Fire-retardant-treated lumber is a standard off-the-shelf product. The key coordination is that the treatment reduces lumber design values — the treater's published strength-adjustment factors must be applied to the NDS values, and members must not be cut after treatment in a way that exposes untreated wood beyond the treater's allowances. (6.4.2)

NOTE Under the prescriptive path, 2x4 bearing studs are limited to 10 ft at 16 in. o.c. and 2x6 bearing studs to 10 ft at 24 in. o.c. (IBC Section 2308.5). Energy code is now an equal driver of stud size: 2x4 walls often cannot accommodate the continuous or cavity insulation required by IECC, so 2x6 at 16 or 24 in. o.c. has become the common exterior bearing wall — confirm the wall assembly with the energy model before fixing stud size. (7.1.2)

NOTE Prescriptive header tables cover clear spans up to roughly 12 ft with No. 2 or better lumber under typical loads; longer spans, point loads, or multi-story tributary loads push the header into engineered LVL or PSL. Where an engineered header is used, coordinate its procurement and reactions with Rough Carpentry so that the member engineered on the structural drawings is the member actually installed. (7.2.2)

NOTE The residential floor design live load is 40 psf (IBC Table 1607.1); sleeping rooms and certain occupancies use lower or higher values, so confirm the controlling live load before selecting from a span table. Douglas Fir-Larch No. 2 and Southern Pine No. 2 are the common species; both list E = 1,600,000 psi in the NDS Supplement, but their bending values differ, so the span table must match the actual species. (8.1.2)

NOTE See Hangers And Supports for the metal connector products used at these conditions. (8.1.5)

NOTE Blocking and bridging keep deep, narrow joists from rotating or buckling laterally under load and distribute concentrated loads between adjacent joists. Without it, joists can roll at the bearing and the floor loses its diaphragm continuity. (8.2.2)

NOTE In a conventional rafter roof, the ceiling joists or rafter ties are the tension members that keep the walls from spreading under roof load; omitting or improperly lapping them lets the ridge sag and the walls bow outward. Pre-engineered wood trusses are an alternative roof system and are designed and supplied separately from this Standard. (9.1.2)

NOTE In most jurisdictions the ground snow load governs the roof design over the 20 psf minimum; the structural drawings carry the controlling roof load for the project. (9.1.4)

NOTE Deck and roof ledger failures are frequently traced to fasteners loaded in withdrawal or to a ledger attached only to wall sheathing rather than to the structure behind it; the ledger connection is an engineered detail. Ledgers in contact with concrete or masonry are also a preservative-treated location. (9.2.2)

NOTE The 80% framing fastener is the 16d common nail (0.162 in. diameter x 3.5 in.). The most common connection RFI in light framing is a mismatch between the shear-wall nailing called on the drawings (for example 8d at 4 in. o.c. at panel edges) and a spec that defaults silently to the standard nailing table — the drawings' schedule must be the controlling document and this Standard must defer to it. (10.1.2)

NOTE These are the prescriptive minimums; shear-wall and high-wind or high-seismic conditions tighten them — for example 3/4 in. diameter bolts at shear-wall ends. The anchorage shown on the structural drawings governs where it is more stringent. (10.2.2)

NOTE Wet-set and post-installed anchors are not interchangeable: post-installed anchors require an ICC-ES report and a separate adhesive or mechanical-anchor specification, and adhesive anchors in tension have edge-distance, embedment, and special-inspection requirements that wet-set bolts do not. (10.2.5)

NOTE Hold-downs anchor the tension chord of a shear wall to the foundation or to the framing below so the wall does not overturn under wind or seismic load. They are sized member by member by the lateral designer; this Standard requires that the scheduled device, anchor, and installation torque be furnished and installed exactly as shown. (10.3.2)

NOTE The structural capacity of a shear wall comes almost entirely from its sheathing nailing schedule — edge nail spacing, panel thickness, and whether panel edges are blocked. The sheathing material is coordinated with the wall assembly and water-resistive barrier; see Gypsum Board Assemblies where gypsum contributes to the assembly rating. (11.1.2)

NOTE The most damaging field decision in wood framing is cutting a structural member to make room for a pipe or duct after the fact. Code limits on notch depth and bored-hole size and location exist because the cut removes load-carrying fiber at the worst location; an over-cut joist or stud must be reinforced or replaced, not concealed. (12.1.3)

NOTE A saw cut exposes untreated heartwood; without field treatment the cut becomes the point where decay begins, defeating the original treatment. This is mandatory for ground-contact and exterior members. (12.2.2)