510 R.I. Code R. 510-RICR-00-00-1.17

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Current through December 3, 2024

Section 510-RICR-00-00-1.17 - Chapter 23: Wood

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:

1. The producing mills shall sell or provide the lumber directly to the ultimate consumer or his contract builder for use in an approved structure;

2. The providing mill shall certify in writing to the consumer or builder on a form to be provided by the State Building Code Standards Committee that the quality and safe working stresses of such lumber are equal to or exceed No. 2 grade in accordance with grading practices established by an approved lumber grading or approved testing agency.

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;

3. Native Lumber shall be limited to the following uses:

a. One (1) and two (2)family dwellings not exceeding three (3) stories in height, or:

b. General building construction types 3B, 4 or 5B not exceeding ten thousand (10,000) square feet of cumulative floor area or thirty-five feet (35') in height, but not to exceed two (2) stories, or:

c. Those low stress buildings not intended for human habitation such as barns, sheds, agricultural, detached garages, outbuildings and other accessory structures; or

d. Non-structural and non-fire rated applications in any use group of Type 3, 4 or 5 constructions.

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

1. Sizing criteria: For lumber sized in accordance with the AF&PA NDS-01, conventional span tables in this code shall be permitted to be used for establishing span and spacing characteristics for all structural members.

2. Stress increases: Lumber which is sized in excess of the dimensions established by the A&PA NDS-01 for the given nominal size referenced shall be allowed to have increased loads providing structural calculations are submitted verifying such increases. See Table 2310.

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
Native Lumber Allowable Stress
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
Column 1	Column 2		Column 4
Nominal Size	Actual Size Thickness Width		Thickness Increase of 1/4" to 1/2	Thickness Increase of over 1/2" to 1"
3 x 8	2-1 /2 x 7-1 /2	1.0 x Fs	+0.10	+0.20
	X 7-3 /4	1.07
	X 8	1.14
3 x 10	2-1 /2 x 9-1 /2	1.0	+0.10	+0.20
	X 9-3 /4	1.05
	X 10	1.11
3 x 12	2-1 /2 x 11-1 /2	1.0	+0.10	+0.20
	X 11-3 /4	1.04
	X 12	1.09
3 x 14	2-1 /2 x 13-1 /2	1.0	+0.10	+0.20
	X 13-3 /4	1.04
	X 14	1.07
4 x 10	3-1 /2 x 9-1 /2	1.0	+0.07	+0.14
	X 9-3 /4	1.05
	X 10	1.11
4 x 12	3-1 /2 x 11-1 /2	1.0	+0.07	+0.14
	X 11-3 /4	1.04
	X 12	1.09
4 x 14	3-1 /2 x 13-1 /2	1.0	+0.07	+0.14
	X 13-3 /4	1.04
	X 14	1.08

Notes to Table 2310
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
Note 2.	Table Columns
Column 1	is the nominal commonly used lumber size
Column 2	is a list of actual sizes of the supplied lumber
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
Column 3	gives the multiplier for increasing the assumed allowable stress (Fs) based on the increases in width as listed in Column 2.
Column 4	gives the multiplier for increasing the assumed allowable stress (Fs) based on increases in thickness
Note 3	Example: Fiber stress for assumed grade = one thousand (1,000) psi - Actual size 3-1 /8 x 9-3 /4
	Nominal size 3 X 10	1. Multiplier factor for Width =	1.05
	3-1 /8 = increase of 5/8" total	2. Multiplier factor for Thickness=	.20
	3. Operating stress F's = 1.25 x Fs F's = 1.25 x 1,000 = 1,250	Sum = 1.25
	Therefore, F's = 1,250 psi is used for calculations and in the span tables

510 R.I. Code R. 510-RICR-00-00-1.17

Amended effective8/1/2019
Amended effective 2/1/2022