Code of Massachusetts Regulations
780 CMR - STATE BOARD OF BUILDING REGULATIONS AND STANDARDS
Chapter 23 - Wood
Section 2304 - GENERAL CONSTRUCTION REQUIREMENTS
Subsection 2304.6 - Wall sheathing
Current through Register 1531, September 27, 2024
Except as provided for in Section 1405 for weatherboarding or where stucco construction that complies with Section 2510 is installed, enclosed buildings shall be sheathed with one of the materials of the nominal thickness specified in Table 2304.6 or any other approved material of equivalent strength or durability.
TABLE 2304.6 MINIMUM THICKNESS OF WALL SHEATHING
| SHEATHING TYPE | MINIMUM THICKNESS | MAXIMUM WALL STUD SPACING |
| Wood boards | 5/8 inch | 24 inches on center |
| Fiberboard | 1/2 inch | 16 inches on center |
| Wood structural panel | In accordance with Tables 2308.9.3(2) and 2308.9.3(3) | - |
| M-S "Exterior Glue" and M-2 "Exterior Glue" Particleboard | In accordance with Tables 2306.5 and 2308.9.3(4) | - |
| Gypsum sheathing | 1/2 inch | 16 inches on center |
| Gypsum wallboard | 1/2 inch | 24 inches on center |
| Reinforced cement mortar | 1 inch | 24 inches on center |
| For SI: 1 inch = 25.4 mm. |
2304.6.1 Wood structural panel sheathing. Where wood structural panel sheathing is used as the exposed finish on the exterior of outside walls, it shall have an exterior exposure durability classification. Where wood structural panel sheathing is used elsewhere, but not as the exposed finish, it shall be of a type manufactured with exterior glue (Exposure 1 or Exterior). Wood structural panel wall sheathing or siding used as structural sheathing shall be capable of resisting wind pressures in accordance with Section 1609. Maximum wind speeds for wood structural panel sheathing used to resist wind pressures shall be in accordance with Table 2304.6.1 for enclosed buildings with a mean roof height not greater than 30 feet (9144 mm), an importance factor (I) of 1.0 and a topographic factor (Kzt) of 1.0.
TABLE 2304.6.1 MAXIMUM BASIC WIND SPEED (mph) (3-SECOND GUST) PERMITTED FOR WOOD STRUCTURAL PANEL WALL SHEATHING USED TO RESIST WIND PRESSURESa, b, c
| MINIMUM NAIL | MINIMUM WOOD STRUCTURAL PANEL SPAN RATING | MINIMUM NOMINAL PANEL THICKNESS (inches) | MAXIMUM WALL STUD SPACING (inches) | PANEL NAIL SPACING | MAXIMUM WIND SPEED (mph) | ||||
| Size | Penetration (inches) | Edges (inches o.c.) | Field (inches o.c.) | Wind exposure category | |||||
| B | C | D | |||||||
| 6d common (2.0"* 0.113") | 1.5 | 24/0 | 3/8 | 16 | 6 | 12 | 110 | 90 | 85 |
| 24/16 | 7/16 | 16 | 6 | 12 | 110 | 100 | 90 | ||
| 6 | 150 | 125 | 110 | ||||||
| 8d common (2.5"* 0.131") | 1.75 | 24/16 | 7/16 | 16 | 6 | 12 | 130 | 110 | 105 |
| 6 | 150 | 125 | 110 | ||||||
| 24 | 6 | 12 | 110 | 90 | 85 | ||||
| 6 | 110 | 90 | 85 | ||||||
| For SI: 1 inch = 25.4 mm, 1 mile per hour = 0.447 m/s.
a. Panel strength axis shall be parallel or perpendicular to supports. Three-ply plywood sheathing with studs spaced more than 16 inches on center shall be applied with panel strength axis perpendicular to supports. b. The table is based on wind pressures acting toward and away from building surfaces in accordance with Section 6.4.2.2 of ASCE 7. Lateral requirements shall be in accordance with Section 2305 or 2308. c. Wood structural panels with span ratings of wall-16 or wall-24 shall be permitted as an alternative to panels with a 24/0 span rating. Plywood siding rated 16 o.c. or 24 o.c. shall be permitted as an alternative to panels with a 24/16 span rating. Wall-16 and plywood siding 16 o.c. shall be used with studs spaced a maximum of 16 inches o.c. |
2304.6.2 Interior paneling. Softwood wood structural panels used for interior paneling shall conform to the provisions of Chapter 8 and shall be installed in accordance with Table 2304.9.1. Panels shall comply with DOC PS 1 or PS 2. Prefinished hardboard paneling shall meet the requirements of CPA/ANSI A135.5. Hardwood plywood shall conform to HPVA HP-1.
