Falsework & Shoring - Cal/OSHA

A shoring system spends most of its life doing nothing, and then, for a few hours on pour day, it carries everything: the concrete, the forms, the crew, the buggies, and whatever gets piled in the wrong place. If it fails, it fails under the people standing on it and on top of the people working below it. California's rule for that system is Title 8, Section 1717, and it adds a step federal OSHA does not have: someone with the right credentials signs off in writing that the system matches its drawings before a yard of concrete is placed. This Cal/OSHA Falsework & Vertical Shoring Toolbox Talk covers who designs it, who inspects it, and what the crew should see on site before the pour.

Where the boundary of this talk sits#

This talk covers California's design, drawing, and certification rules for falsework and vertical shoring. Building and stripping formwork, and watching the shores on pour day, belong to their own talks.

The anchor#

Here is the distinction that carries this whole talk: in California a shoring system is not ready for concrete when it looks right — it is ready when the person the rule names has inspected it against the working drawings and certified in writing that it substantially conforms and that the material and workmanship are satisfactory, and that certification is on the job site — so the question before the first truck is not "is the shoring up?" but "who signed for it, against which drawings, and where is the paper?"; above 14 feet high, over 16-foot spans, or over traffic, that signature has to come from a California-registered civil engineer or their authorized representative.

Design loads#

Section 1717(a) requires formwork and falsework or shoring to be designed, erected, supported, braced, and maintained to safely withstand all intended loads during erection, construction, usage, and removal. It sets minimums:

• a total design load of not less than 100 pounds per square foot for the combined live and dead load, regardless of slab thickness;
• a minimum allowance for live load and formwork of not less than 20 pounds per square foot in addition to the weight of the concrete;
• additional allowances where carts are used — 10 pounds per square foot for worker-propelled carts and 25 pounds per square foot for motorized carts; and
• lateral loads for shoring, resisted at each floor in both directions by diagonal bracing or other means, of not less than 100 pounds per lineal foot of floor edge or two percent of the total dead load, whichever is greater.

Those numbers are why "we'll just add a few more shores" is not a design.

Who has to sign the drawings#

Section 1717(b)(1) requires detailed design calculations and working drawings approved and signed by a civil engineer currently registered in California for all falsework or vertical shoring installations where any of the following exists:

• the height, measured from the top of the sills to the soffit of the superstructure, exceeds 14 feet;
• individual horizontal span lengths exceed 16 feet; or
• provisions are made for vehicular or railroad traffic through the falsework or shoring.

For all other installations, Section 1717(b)(2) requires the falsework plan or shoring layout to be approved and signed by a civil engineer currently registered in California, a manufacturer's authorized representative, or a licensed contractor's representative qualified in the usage and erection of falsework and vertical shoring.

Section 1717(b)(3) requires a falsework plan or shoring layout to be available on the job site at all times. Section 1717(b)(4) requires all vertical supports to be erected on a properly compacted, reasonably level, and stable base, with plates, pads, and soil bearing capacity adequate for the imposed loads. A shore on soft, wet ground has a design problem no drawing can fix.

Certified in writing before the pour#

Section 1717(c) is where California goes furthest.

For installations under (b)(1) — over 14 feet, over 16-foot spans, or over traffic — after the system is built and before concrete is placed, a civil engineer currently registered in California, or an authorized representative, must inspect it for conformity with the working drawings. The person performing the inspection certifies in writing that the system substantially conforms to the working drawings and that the material and workmanship are satisfactory.

For all other installations, the inspection before concrete placement is made by a California-registered civil engineer, a manufacturer's authorized representative, or a licensed contractor's representative qualified in falsework and vertical shoring. That person certifies in writing that the system conforms to the working drawings and that the material and workmanship are satisfactory.

In both cases, the certification must be available at the job site.

Stay out from under it, and don't strip too soon#

Section 1717(d) prohibits employees from working below a building floor form installation, except those actually engaged in its installation, removal, or inspection. The space under a deck being formed or poured is not a shortcut or a staging area.

Section 1717(e) says formwork and shores, except for slabs on grade and slip forms, shall not be removed until the employer determines that the concrete has gained sufficient strength to support its weight and superimposed loads. Reshoring shall not be removed until the concrete being supported has attained the strength to support its weight and all loads placed upon it.

Tall falsework also needs a permit#

Separately from Section 1717, Section 341(d)(5)(B) requires a Cal/OSHA permit for the erection and placement of scaffolding, vertical shoring, or falsework intended to be more than 36 feet high when completed. That is covered in the Cal/OSHA construction permits talk.

California versus federal#

The federal rule, 29 CFR 1926.703, requires formwork to be designed to support all vertical and lateral loads, requires drawings or plans for the jack layout, formwork, shoring, working decks, and scaffolds to be available at the jobsite, and requires erected shoring to be inspected immediately before, during, and immediately after concrete placement. It does not set California's 14-foot and 16-foot triggers for a registered civil engineer, the 100-pound-per-square-foot minimum design load, or the written certification before the pour. The stripping rule is essentially the same in both.

Where the duty sits#

8 CCR 1717 carries the California duty: (a) design loads; (b) engineer-signed drawings above 14 feet, over 16-foot spans, or with traffic, other plans signed by a qualified person, drawings on site, stable base; (c) inspection and written certification before concrete placement, kept on site; (d) no work below a floor form installation except those installing, removing, or inspecting; (e) stripping and reshoring. 8 CCR 341(d)(5)(B) requires a permit over 36 feet. For contrast, federal 29 CFR 1926.703.

What can go wrong?#

• Shores go up to 18 feet from a supplier's typical layout with no engineer's signature.
• The pour starts before anyone signs the written certification.
• The shoring layout is in the office, not on the job.
• Shores are set on loose fill after rain.
• Laborers take a shortcut under a deck that is being poured.

How do we manage this properly?#

• Check the triggers — over 14 feet, over 16-foot spans, or traffic means a California-registered civil engineer.
• Keep the drawings on site — the shoring layout or falsework plan, at all times.
• Build on a stable base — compacted, level, with adequate plates and pads.
• Certify before the pour — in writing, by the right person, kept on site.
• Nobody under the deck — except those installing, removing, or inspecting.
• Strip and reshore on strength — not on the schedule.

Before you start#

Before the first truck, ask to see the shoring layout or falsework plan and the written certification for this pour. Check who signed each one. Walk the base of the shores.

Talk it over#

• Where are the shoring drawings for this deck?
• Who certified this system, and when?
• Where is it tempting to cut under the deck, and how do we stop it?

The bottom line#

In California, a shoring system is ready for concrete when it has been inspected against its drawings and certified in writing by the right person, with that certification on site. Above 14 feet high, over 16-foot spans, or with traffic through it, the drawings and the inspection belong to a California-registered civil engineer. Design to at least 100 pounds per square foot, build on a stable base, keep people out from under the deck, and strip only when the concrete is strong enough.

Frequently asked questions about Cal/OSHA falsework and shoring#

When does California require a registered civil engineer for shoring?

Under Section 1717(b)(1), when the height from the top of the sills to the soffit exceeds 14 feet, when individual horizontal spans exceed 16 feet, or when provisions are made for vehicular or railroad traffic through the falsework or shoring. The engineer must be currently registered in California.

Download the Cal/OSHA falsework and shoring toolbox talk PDF#

Download this Cal/OSHA Falsework & Vertical Shoring Toolbox Talk as a printable PDF in English and Spanish, and check the certification against it before the first truck arrives.

Related toolbox talks#

• Formwork Safety
• Concrete Pumping Safety
• Scaffolding Safety
• Dropped Objects

Sources#

• Cal/OSHA, Title 8 CCR §1717 — Falsework and Vertical Shoring ((a) design for all intended loads, 100 psf minimum total, 20 psf live load and formwork, 10 and 25 psf for carts, lateral load 100 plf or 2% of dead load; (b)(1) California-registered civil engineer for height over 14 ft, spans over 16 ft, or traffic; (b)(2) other installations by engineer, manufacturer's representative, or qualified licensed contractor's representative; (b)(3) plan on site; (b)(4) stable base; (c) inspection and written certification before concrete placement, available at the job site; (d) no work below a floor form installation except installation, removal, or inspection; (e) stripping and reshoring): https://www.dir.ca.gov/title8/1717.html
• Cal/OSHA, Title 8 CCR §341 ((d)(5)(B) permit for scaffolding, vertical shoring, or falsework intended to be more than 36 ft high): https://www.dir.ca.gov/title8/341.html
• OSHA, 29 CFR 1926.703 (federal: (a)(1) design for all loads; (a)(2) drawings at the jobsite; (b)(3) inspection before, during, and after placement; (b)(4) reinforce damaged shoring; (e)(1) stripping when concrete has sufficient strength): https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.703

Written by FieldSafetyTalk's safety professional — a CSP, ASP, CHST and OSHA Authorized Outreach Trainer with 14+ years of international construction safety experience across federal, heavy civil, and industrial projects.

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