Building Code Standards

1997 Uniform Building Code

Chapter 35

UNIFORM BUILDING CODE STANDARDS

Part I - General

SECTION 3503

STANDARD OF DUTY

The standard of duty established for the recognized standards listed in Part IV of this chapter is that the design, construction and quality of materials of buildings and structures be reasonably safe for life, limb, health, property and public welfare.

SECTION 3504

RECOGNIZED STANDARDS

The standards listed in Part IV of this chapter are recognized standards. Compliance with these recognized standards shall be prima facie evidence of compliance with the standard of duty set forth in Section 3503.

Chapter 23

WOOD

NOTE: This chapter has been revised in its entirety

SECTION 2302 - DEFINITIONS

2302.1 Definitions. The following terms used in this chapter shall have the meanings indicated in this section:

AWPA is the American Wood-Preservers' Association, PO Box 388, Selma, Alabama 36702 Phone: 334-874-9800 Fax: 334-874-9008

email: email@awpa.com

TREATED WOOD is wood treated with an approved preservative under treating and quality control procedures.

WOOD OF NATURAL RESISTANCE TO DECAY OR TERMITES is the heartwood of the species set forth below. Corner sapwood is permitted on 5 percent of the pieces provided 90 percent or more of the width of each side on which it occurs is heartwood. Recognized species are:

Decay resistant: Redwood, Cedars, Black Locust

Termite resistant: Redwood, Eastern Red Cedar

SECTION 2303 - STANDARDS OF QUALITY

The other standards listed below are recognized standards. (See Sections 3503 and 3504)

3. Preservative Treatment by Pressure Process and Quality Control.

3.1 Standard Specifications C1, C2, C3, C4, C9, C14, C15, C16, C22, C23, C24, C28 and M4, of the American Wood-Preservers' Association.

SECTION 2304 - MINIMUM QUALITY

2304.1 Quality and Identification. All lumber, wood structural panels, particleboard, structural glued-laminated timber, end-joined lumber, fiberboard sheathing (when used structurally), hardboard siding (when used structurally), piles and poles regulated by this chapter shall conform to the applicable standards and grading rules specified in this code and shall be so identified by the grade mark or certificate of inspection issued by an approved agency.

All preservatively treated wood required to be treated under Section 2306 shall be identified by the quality mark of an inspection agency which has been accredited by an accreditation body which complies with the requirements of the American Lumber Standards Committee Treated Wood Program, or equivalent.

2304.3 Timber Connectors and fasteners.

Fasteners for pressure-preservative treated and fire-retardant treated wood shall be of hot-dipped zinc coated galvanized, stainless steel, silicon bronze or copper. Fasteners for wood foundations shall be as required in Chapter 18, Division II. Fasteners required to be corrosion resistant shall be either zinc- coated fasteners, aluminum alloy wire fasteners or stainless steel fasteners.

Division II - GENERAL REQUIREMENTS

Part I - REQUIREMENTS APPLICABLE TO ALL DESIGN METHODS

SECTION 2306 - DECAY AND TERMITE PROTECTION

2306.2 Wood Support Embedded in Ground. Wood embedded in the ground or in direct contact with the earth and used for the support of permanent structures shall be treated wood unless continuously below the groundwater line or continuously submerged in fresh water. Round or rectangular posts, poles and sawn timber columns supporting permanent structures which are embedded in concrete or masonry in direct contact with earth or embedded in concrete or masonry exposed to the weather shall be treated wood. The wood shall be treated for ground contact.

2306.3 Under-floor Clearance. When wood joists or the bottom of wood structural floors without joists are located closer than 18 inches (457mm) or wood girders are located closed than 12 inches (305mm) to exposed ground in crawl spaces or unexcavated areas located within the periphery of the building foundation, the floor assembly, including posts, girders, joists and subfloor, shall be approved wood of natural resistance to decay as listed in Section 2306.4 or treated wood.

2306.4 Plates, sills and sleepers. All foundation plates or sills and sleepers on a concrete or masonry slab, which is In direct contact with earth, and sills which rest on concrete or masonry foundations, shall be treated wood or foundation redwood, all marked or branded by an approved agency. Foundation cedar or No. 2 Foundation redwood marked or branded by an approved agency may be used for sills in territories subject to moderate hazard, where termite damage is not frequent and when specifically approved by the building official. In territories where hazard of termite damage is slight, any species of wood permitted by this code may be used for sills when specifically approved by the building official.

2306.5 Columns and Posts. Columns and posts located on concrete or masonry floors or decks exposed to the weather or to water splash or in basements and that support permanent structures shall be supported by concrete piers or metal pedestals projecting above floors unless approved wood of natural resistance to decay or treated wood is used. The pedestals shall project at least 6 inches (152mm) above exposed earth and at least 1 inch (25mm) above such floors.

Individual concrete or masonry piers shall project at least 8 inches (203mm) above exposed ground unless the columns or posts that they support are of approved wood of natural resistance to decay or treated wood is used.

2306.6 Girders Entering Masonry or Concrete Walls. Ends of wood girders entering masonry or concrete walls shall be provided with a 1/2 - inch (12.7mm) air space on tops, sides and ends unless approved wood of natural resistance to decay or treated wood is used.

2306.8 Wood and Earth Separation. Protection of wood against deterioration as set forth in the previous sections for specified applications is required. In addition, wood used in construction of permanent structures and located nearer that 6 inches (152mm) to earth shall be treated wood or wood of natural resistance to decay, as defined in section 2302.1. Where located on concrete slabs placed on earth, wood shall be treated wood or wood of natural resistance to decay. Where not subject to water splash or to exterior moisture and located on concrete having a minimum thickness of 3 inches (76mm) with an impervious membrane installed between concrete and earth, the wood may be untreated and of any species.

2306.9 Wood Supporting Roofs and Floors. Wood structural members supporting moisture-permeable floors or roofs that are exposed to the weather, such as concrete or masonry slabs, shall be approved wood of natural resistance to decay or treated wood unless separated from such floors or roofs by an impervious moisture barrier.

2603.10 Moisture Content of Treated Wood. When wood pressure treated with a water-borne preservative is used in enclosed locations where drying in service cannot readily occur, such wood shall be at a moisture content of 19 percent or less before being covered with insulation, interior wall finish, floor covering or other material.

2306.11 Retaining Walls. Wood used in retaining walls or crib walls shall be treated wood.

2306.12 Weather Exposure. Those portions of glued-laminated timbers that form the structural supports of a building or other structure and are exposed to weather and not properly protected by a roof, eave overhangs of similar covering shall be pressure treated with an approved preservative or be manufactured from wood of natural resistance to decay.

All wood structural panels, when designed to be exposed in outdoor applications, shall be of exterior type, except as provided in Section 2306.2.

In geographical areas where experience has demonstrated a specific need, approved wood of natural resistance to decay or treated wood shall be used for those portions of wood members which form the structural supports of buildings, balconies, porches or similar permanent building appurtenances when such members are exposed to the weather without adequate protection from a roof, eave, overhang or other covering to prevent moisture or water accumulation on the surface or at joints between members. Depending on local experience, such members may include horizontal members such as girders, joists and decking; or vertical members such as posts, poles and columns; or both horizontal and vertical members.