Code of Massachusetts Regulations › 780 CMR - STATE BOARD OF BUILDING REGULATIONS AND STANDARDS › Chapter 15 - Roof Assemblies and Rooftop Structures › Section 1507 - REQUIREMENTS FOR ROOF COVERINGS › Subsection 1507.8 - Wood shingles

Current through Register 1525, July 5, 2024
The installation of wood shingles shall comply with the
				  provisions of this section and Table 1507.8.
TABLE 1507.8 WOOD SHINGLE AND SHAKE
				  INSTALLATION
ROOF ITEM
WOOD SHINGLES
WOOD SHAKES
1. Roof slope
Wood shingles shall be installed on slopes of three
							 units vertical in 12 units horizontal (3:12) or greater.
Wood shakes shall be installed on slopes of four units
							 vertical in 12 units horizontal (4:12) or greater.
2. Deck requirement
Temperate climate
Shingles shall be applied to roofs with solid or spaced
							 sheathing. Where spaced sheathing is used, sheathing boards shall not be less
							 than 1' *4'nominal dimensions and shall be spaced on center equal to the
							 weather exposure to coincide with the placement of fasteners.
Shakes shall be applied to roofs with solid or spaced
							 sheathing. Where spaced sheathing is used, sheathing boards shall not be less
							 than 1' *4'nominal dimensions and shall be spaced on center equal to the
							 weather exposure to coincide with the placement of fasteners. When 1' *4'spaced
							 sheathing is installed at 10 inches, boards must be installed between the
							 sheathing boards.
In areas where the average daily
							 temperature in January is 25°F or less or where there is a possibility of
							 ice forming along the eaves causing a backup of water.
Solid sheathing required.
Solid sheathing is required.
3. Interlayment
No requirements.
Interlayment shall comply with ASTM D 226, Type 1.
4. Underlayment
Temperate climate
Underlayment shall comply with
ASTM D 226,
							 Type 1.
Underlayment shall comply with
ASTM D 226,
							 Type 1.
In areas where there is a possibility of ice forming
							 along the eaves causing a backup of water.
An ice barrier that consists of at least two layers of
							 underlayment cemented together or of a self-adhering polymer-modified bitumen
							 sheet shall extend from the eave's edge to a point at least 24 inches inside
							 the exterior wall line of the building.
An ice barrier that consists of at least two layers of
							 underlayment cemented together or of a self-adhering polymer-modified bitumen
							 sheet shall extend from the lowest edges of all roof surfaces to a point at
							 least 24 inches inside the exterior wall line of the building.
5. Application
Attachment
Fasteners for wood shingles shall be hot- dipped
							 galvanized or Type 304 (Type 316 for coastal areas) stainless steel with a
							 minimum penetration of 0.75 inch into the sheathing. For sheathing less than
							 0.5 inch thick, the fasteners shall extend through the sheathing.
Fasteners for wood shakes shall be hot-dipped
							 galvanized or Type 304 (Type 316 for coastal areas) with a minimum penetration
							 of 0.75 inch into the sheathing. For sheathing less than 0.5 inch thick, the
							 fasteners shall extend through the sheathing.
No. of fasteners
Two per shingle.
Two per shake.
Exposure
Weather exposures shall not exceed those set forth in
							 Table 1507.8.7.
Weather exposures shall not exceed those set forth in
							 Table 1507.9.8.
Method
Shingles shall be laid with a side lap of not less than
							 1.5 inches between joints in courses, and no two joints in any three adjacent
							 courses shall be in direct alignment. Spacing between shingles shall be 0.25 to
							 0.375 inch.
Shakes shall be laid with a side lap of not less than
							 1.5 inches between joints in adjacent courses. Spacing between shakes shall not
							 be less than 0.375 inch or more than 0.625 inch for shakes and taper sawn
							 shakes of naturally durable wood and shall be 0.25 to 0.375 inch for
							 preservative-treated taper sawn shakes.
Flashing
In accordance with Section 1507.8.8.
In accordance with Section 1507.9.9.
For SI: 1 inch = 25.4 mm, °C = [(°F) -
							 32]/1.8.
1507.8.1
Deck requirements.
Wood shingles shall be installed on solid or spaced
				sheathing. Where spaced sheathing is used, sheathing boards shall not be less
				than 1-inch by 4-inch (25 mm by 102 mm) nominal dimensions and shall be spaced
				on centers equal to the weather exposure to coincide with the placement of
				fasteners.
1507.8.1.1
Solid sheathing
				required.
Solid sheathing is required in areas where the average daily
				temperature in January is 25°F (-4°C) or less or where there is a
				possibility of ice forming along the eaves causing a backup of water.