Rhode Island Code of Regulations
Title 510 - Building Code Commission
Chapter 00 - N/A
Subchapter 00 - N/A
Part 1 - RISBC-1 Rhode Island Building Code
Section 510-RICR-00-00-1.17 - Chapter 23: Wood
Current through September 18, 2024
Add the following exception to IBC section 2303.1.1 Lumber
Exception:
Native Lumber used in accordance with Rhode Island amendment section 2310.
Add the following new section 2310 Native Lumber:
2310 Native Lumber.
2310.1 Scope:
The provisions of this section shall govern the use of Native Lumber in accordance with R.I. Gen. Laws § 23-27.3-109.0 of the State Building Code.
Native Lumber is unmarked structural lumber from wood processed in the State of Rhode Island by a mill registered in accordance with provisions of this code.
Such lumber which is not grade marked or certified by a recognized grading organization designated under section 2303.1.1 shall be classified as an ordinary material and is not required to meet the test requirement of section 1709.2 and shall be permitted for use as follows.
2310.2 Identification and Use:
Exception: Load bearing walls shall be of stud grade minimum.
This certification shall be filed with the local building official having jurisdiction as part of the building permit application;
Uses not permitted: Native lumber shall not be used in engineered platetruss systems unless such lumber is graded in accordance with section 2303.1.1.
2310.3 Native Softwoods and Hardwoods
Native hardwood or softwood lumber may be used in post and beam timber type construction per section 602.4. Such uses as beam, girders, headers, and column supports will require engineering evaluation for the allowable design values and duration of loading factors for all buildings other than One (1) amp; Two (2) Family Dwellings.
Native lumber located near or in contact with the ground shall be naturally durable or pressure-treated in accordance with the provisions of section 2304.12.
2310.4 Sizing Criteria for Native Softwood Lumber
2310.5 Moisture Content
The moisture content for structural framing shall be nineteen percent (19%) or less unless the producer indicates that the lumber is surfaced green.
2310.6 Post and Beam Type Structures
Native hardwood and softwood lumber are permitted in post and beam timber-type structures. Design drawings and calculation shall be by a Rhode Island registered architect or engineer and submitted to the building official for approval.
2310.7 Responsibilities
The building official shall indicate the use of native lumber on the building permit application under the heading "Description of work to be performed" and also the name of the mill providing the native lumber.
The building official shall have the right to reject any lumber of questionable quality based on visual observation.
Table 2310 |
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Native Lumber Allowable Stress |
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Actual Lumber Size Closest Size which does not exceed the Dimensions Shown |
Multiplier Factor Lumber Based on Width |
Factor to be Added to Column 3 Factor for Lumber Oversized in Thickness |
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Column 1 |
Column 2 |
Column 4 |
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Nominal Size |
Actual Size Thickness Width |
Thickness Increase of 1/4" to 1/2 |
Thickness Increase of over 1/2" to 1" |
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3 x 8 |
2-1 /2 x 7-1 /2 |
1.0 x Fs |
+0.10 |
+0.20 |
X 7-3 /4 |
1.07 |
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X 8 |
1.14 |
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3 x 10 |
2-1 /2 x 9-1 /2 |
1.0 |
+0.10 |
+0.20 |
X 9-3 /4 |
1.05 |
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X 10 |
1.11 |
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3 x 12 |
2-1 /2 x 11-1 /2 |
1.0 |
+0.10 |
+0.20 |
X 11-3 /4 |
1.04 |
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X 12 |
1.09 |
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3 x 14 |
2-1 /2 x 13-1 /2 |
1.0 |
+0.10 |
+0.20 |
X 13-3 /4 |
1.04 |
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X 14 |
1.07 |
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4 x 10 |
3-1 /2 x 9-1 /2 |
1.0 |
+0.07 |
+0.14 |
X 9-3 /4 |
1.05 |
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X 10 |
1.11 |
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4 x 12 |
3-1 /2 x 11-1 /2 |
1.0 |
+0.07 |
+0.14 |
X 11-3 /4 |
1.04 |
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X 12 |
1.09 |
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4 x 14 |
3-1 /2 x 13-1 /2 |
1.0 |
+0.07 |
+0.14 |
X 13-3 /4 |
1.04 |
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X 14 |
1.08 |
Notes to Table 2310 |
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Note 1. |
Notation FS is the allowable maximum fiber stress for the assumed grade as established by this code in Section 2309.2.2 F's ("operating" stress) is the modified allowable maximum fiber stress which may be used in the span tables and for calculating required lumber sizes. F's is found by multiplying Fs by the factors given in the table |
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Note 2. |
Table Columns |
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Column 1 |
is the nominal commonly used lumber size |
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Column 2 |
is a list of actual sizes of the supplied lumber |
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Column 2 |
lists the sizes on the basis of a constant thickness and a width increasing by one- quarter (1/4") inch and one half (1/2") inch |
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Column 3 |
gives the multiplier for increasing the assumed allowable stress (Fs) based on the increases in width as listed in Column 2. |
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Column 4 |
gives the multiplier for increasing the assumed allowable stress (Fs) based on increases in thickness |
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Note 3 |
Example: Fiber stress for assumed grade = one thousand (1,000) psi - Actual size 3-1 /8 x 9-3 /4 |
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Nominal size 3 X 10 |
1. Multiplier factor for Width = |
1.05 |
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3-1 /8 = increase of 5/8" total |
2. Multiplier factor for Thickness= |
.20 |
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3. Operating stress F's = 1.25 x Fs F's = 1.25 x 1,000 = 1,250 |
Sum = 1.25 |
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Therefore, F's = 1,250 psi is used for calculations and in the span tables |