Code of Massachusetts Regulations › 780 CMR - STATE BOARD OF BUILDING REGULATIONS AND STANDARDS › Chapter 23 - Wood › Section 2304 - GENERAL CONSTRUCTION REQUIREMENTS › Subsection 2304.11 - Protection against decay and termites

Current through Register 1525, July 5, 2024
2304.11.1
General.
Where
				required by this section, protection from decay and termites shall be provided
				by the use of naturally durable or
preservative-treated
				wood
.
2304.11.2
Wood
				used above ground.
Wood used above ground in the locations specified in
				Sections 2304.11.2.1 through 2304.11.2.7, 2304.11.3 and 2304.11.5 shall be
				naturally durable wood or
preservative-treated wood
using
				water-borne preservatives, in accordance with AWPA U1 (Commodity Specifications
				A or F) for above-ground use.
2304.11.2.1
Joists, girders and subfloor.
Where wood joists or the bottom of a
				wood structural floor without joists are closer than 18 inches (457 mm), or
				wood girders are closer than 12 inches (305 mm) to the exposed ground in crawl
				spaces or unexcavated areas located within the perimeter of the building
				foundation, the floor construction (including posts, girders, joists and
				subfloor) shall be of naturally durable or
preservative-treated
				wood
.
2304.11.2.2
Wood supported by exterior foundation walls.
Wood framing members,
				including wood sheathing, that rest on exterior foundation walls and are less
				than 8 inches (203 mm) from exposed earth shall be of naturally durable or
preservative-treated wood
.
2304.11.2.3
Exterior walls below
				grade.
Wood framing members and furring strips attached directly to the
				interior of exterior masonry or concrete walls below grade shall be of
approved
naturally durable or
preservative-treated
				wood
.
2304.11.2.4
Sleepers and sills.
Sleepers and sills on a concrete or masonry slab
				that is in direct contact with earth shall be of naturally durable or
preservative-treated wood
.
2304.11.2.5
Girder ends.
The
				ends of wood girders entering exterior masonry or concrete walls shall be
				provided with a 1/2-inch
				(12.7 mm) air space on top, sides and end, unless naturally durable or
preservative-treated wood
is used.
2304.11.2.6
Wood siding.
Clearance between wood siding and earth on the exterior of a building shall not
				be less than 6 inches (152 mm) or less than 2 inches (51 mm) vertical from
				concrete steps, porch slabs, patio slabs and similar horizontal surfaces
				exposed to the weather except where siding, sheathing and wall framing are of
				naturally durable or
preservative-treated wood
.
2304.11.2.7
Posts or columns.
Posts or columns supporting permanent structures and supported by a concrete or
				masonry slab or footing that is in direct contact with the earth shall be of
				naturally durable or
preservative-treated wood
.
Exceptions:
1. Posts or columns that are either exposed
				to the weather or located in basements or cellars, supported by concrete piers
				or metal pedestals projected at least 1 inch (25 mm) above the slab or deck and
				6 inches (152 mm) above exposed earth, and are separated therefrom by an
				impervious moisture barrier.
2.
				Posts or columns in enclosed crawl spaces or unexcavated areas located within
				the periphery of the building, supported by a concrete pier or metal pedestal
				at a height greater than 8 inches (203 mm) from exposed ground, and are
				separated therefrom by an impervious moisture barrier.