Heavy Duty Bar Grating Specification Criteria - Grating Pacific

Bearing Bar Selection

Once the bar spacing is selected, the bearing bar size must be specified based upon the Maximum Traffic Conditions and the unsupported clear span to be served.  Consult the Load Tables for the maximum clear span of our most popular products. 

You can find more information on our web, so please take a look.

For maximum durability, our load tables incorporate strict limitations where design deflection shall not exceed the lesser of L/400 or .125″ for the spans indicated.

Cross Bar Selection

While bearing bar selection is critical for specifying a proper heavy duty grating, the life cycle of your installation will often be influenced by the selection of the appropriate cross bar. The table below details the variety of cross bar sizes available.

The cross bars listed for Standard Loads are the customary twisted square or round cross bars supplied by Grating Pacific for a particular bearing bar size and spacing. These sizes have been selected to maximize manufacturing efficiency and are best used when the grating is subject to intermittent traffic with occasional full capacity loading.

The cross bars listed for Severe Loads are optional and will provide superior durability when gratings are subject to intense, continuous, or repetitious traffic.  These robust cross bars increase lateral stiffness thereby extending the service life of the grating. When specifying gratings with bearing bars centered at 1-3/8″, 1-7/8″, or 2-3/8″ on center, consideration of Severe Loading cross bars is highly recommended.

Note: In the event that a cross bar size is not specified, the cross bar shall be selected at the discretion of the manufacturer.

Brown-Campbell has developed this simple tool to help you determine what type of 19W4/19W2 bar grating will suit your needs the best.

To use this calculator, select a Span AND select either a U-Load OR C-Load quantity. The calculator will then recommend the appropriate bar size of 19W4/19W2 bar grating based on your specified criteria.

You will get efficient and thoughtful service from Shunbo Steel Grating.

For example, by selecting a span of 2’ 0” with a U-Load of 533, the recommended bar size would be
3/4” x 3/16” 19W4/19W2.

Notes:

* Approximate weight Lbs./Sq. Ft. Weight depends on panel width, cross bar selection, mill tolerance, and manufacturing tolerance.
** Recommended maximum span for 1/4’’ deflection under concentrated load at 300# at midspan on 6’ or less. 400# over 6’.
*** Deflection in inches.

¹ Uniform Concentrated Load Lb/Sq. Ft.
² Safe Concentrated Load Lb/Sq. Ft. of grating width, at mid-span.

1/4’’ is recommended as the maximum deflection consistent with pedestrian comfort but can be exceeded for other loading conditions at the discretion of the engineer.

The carrying capacity of a piece of grating subjected to a concentrated load over only a portion of it’s width is determined by the stiffness of both the bearing bars and the cross bars, and therefor differs with the type of grating used. To determine the carrying capacity of gratings subject to such loading the manufacturer’s engineering department should be consulted.

Conversion Factors:

For gratings with other than 1-3/16’’ bearing or spacing or for different design stresses, proportionate conversion factors apply. For information on other types of grating consult the manufacturer.

Disclaimer:

This bar grating calculator is intended for informational purposes only for pedestrian traffic. It has been developed using load table information supplied by the National Association of Architectural Metal Manufacturers for steel welded bar grating type 19W4/19W2. This information is of a technical nature, and as such is intended only for evaluation by technically skilled persons, with any use thereof to be at their independent discretion and risk. Such information is reliable when evaluated in the proper manner by licensed engineering personnel. Brown-Campbell shall have no responsibility or liability for results obtained or damages resulting from improper evaluation or use.

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