Ciry of los Angeles Develops Spon Tobles for Girdetsr Joists clnd R.crfters

The following "Span Tables" were developed by the Department of Building and Safety, City of Los Angeles, California, to be embodied in its new Building Code to become effective on or about July 15, 1957,at which time the city will require all lumber, in all grades, to be "grade-stamped."

The CALIFORNIA LUMBER MERCHANT is indebted to Orrie W. Hamilton. executive vice-president of the Southern California Retail Lumber Associationj for permission to reproduce the tables from its June 20 bulletin to its members. The association plans to furnish copies of these Span Tables to all architects in the area and solicit their cooperation in specifying materials that are available for quick delivery, to make better and stronger buildings at lower cost of construction.

With the SCRLA bulletin, Mr. Hamilton told his dealer members that any suggestions they might have along the lines of promoting the use of "grade-stamped" standard-construction lumber would be greatly appreciated.

It should be noted in the following Span Tables that the Douglas Fir grades arc listed therein as "Coast" and "fnland."

The "Coast" denotes lumber graded by any recognized grading agency (i.e. W.C.L.B., P.L.T.B., etc.) under the Standard Grading and Dressing Rules No. 15 of the West Coast Lumber Inspection Bureau. Where the word "Inland' is used, it denotes lumber graded under the 1956 Standard Grading Rules of the Western Pine Association:

TABLE NO. It-J MAXIMTJM CLEAR SPANS FOR RAI"TERS ALLOWABLE SPAN

Specles-Mtntmum Grade

TABLE NO. I8-IT MAXIMUM CLEAR SPANS FOR CEILING JOISTS ALLOWABLE SPAN

Grade SPECIES-Mlnlmum Grade

Douglas Ftr (Coast)-Std. Caltf, Redwood-H@rt

Southera PlneNo. 2 Dlm. Struc. * *

Weot C.oast Hemlck-Std. Whlte Flr-Constr.*r*

Larch-No. 1Dtm.* Whlte Flr-No. 1 Dlm.*

Douglas Ftr (Inland) No. 1 Sttka SprucFconstr.r*r Dlm.'

' May be of Gra.de "No. 2 Dim." in 2x4 eize.

'r May be of "Sap Common" Grade in 2x4 eize.

'rt Mey tre of "Staudsrd" Grade in 2x4 size.

TABLE NO. 'It.E ALLOWABLE SPANS FOR FLOOR JOISTSI ALLOWABLE SPAN SPBCIES-Mtnlmum Grade SPECIES-Mlnlmum Grade DouEhs Ftr (Coaot)-Std. Csltf. Redwood-Hart Southm PlnFNo. 2 Dtm. Strut. West Corst Hemlck-Std. Tyhlte Flr-Const.

At the meeting of June 17,1957, the Board of Building and Safety Commissioners, City of Los Angeles, approved the use of Utility grade and No. 4lumber with the following provisions to become effective concurrently with the 1957 Building Code Amendments and to remain in effect on a trial basis for a period of one year:

1. "Utility" grade and "No.4" lumber of less thanT'nominal thickness may be used in the following locations: a. For sub-flooring where the finish floor has a thickness of not less than !{". b. For wall sheathing in any location.

2. "Vtility" grade lumber may be used to the extent of l5/o for studs in one-story buildings or in the top story of multi-story buildings where the arbitrary design criteria of Division 48 are applicable and engineering design is not required.

3. "Utility" grade lumber may be used in any location for

TABLE NO. I8-D SPAN OF GIRDERS CARRYING FLOOR JOISTS ALLOWABLE SPAN SPECIE$-Mtnlmum Grade SPECIES-Mlnlmum Gmde Douglas Flr (Coast)-Std- Caltf. Redwood-H€art Southm Plne-No.2 Dlm. Stru. West CoaEt Hemlock-Std. Whlte Ftr-Const. Larch-No. l Dlm. Tfhlte Ftr-No. 1Dlm. DouElas Flr (Inland) No. 1 Sttka SprucFconst. Dtm. Not Not SupportlnE Suplnrtlng Supporttnc Supportlng Partltlons Partltlons Psrtltlono Partltlon3 blocking, bridging, fire stops, and short cripples. All "Utility" or "No. 4" lumber shall bear a grade mark stamp on the lumber by an approved grading agency except that when sheathing is developed by resawing 2" dimension lumber, only every second piece_ will need to bear the stamp.

All "Utility" or "No. 4" lumber shall be subject to the approval of ttte guitding Inspector. If not acceptable such lumber shall be removed or shall be supported by the addition of satisfactory material.

Bulletin dated June 17,1957, from the Department of Building and Safety, City of Los Angeles, to become effective with the 1957 Building Code amendments (including the "Span Tables"), or on or about July 15, 1,957, is quite clear except that ,vhen lumber grades are referred to by names, it means (Continued on Page 58)