TWK/Specific/TBT-TWK-002

Formwork and Falsework

Temporary WorksSpecificFormwork and Falsework

All Categories/Temporary Works/Specific/Formwork and Falsework

Formwork and Falsework

Toolbox Talk Record

Ref: TBT-TWK-002  |  Issue: 1  |  Date: March 2026
PresenterProject
LocationDate

What?

  • Formwork is the temporary mould into which concrete is poured; falsework is the temporary structure supporting the formwork.
  • Falsework collapse during concrete pours is one of the most catastrophic failures that occurs on construction sites.
  • BS 5975 requires all formwork and falsework to be designed by a competent person and independently checked before use.
  • A permit to load must be issued by the temporary works coordinator before any concrete is placed into the formwork.
  • Falsework must be erected exactly as designed — changes to prop positions, bracing, or base conditions invalidate the design.
  • Foundations for falsework props must be on firm ground with sole plates to spread the load and prevent settlement.
  • Formwork must be oiled or treated with release agent before reinforcement is fixed to allow clean stripping later.
  • Striking of formwork must only occur when concrete has reached the required strength, confirmed by cube test results.
  • Inspection of formwork and falsework must take place before, during, and after the concrete pour to detect movement.
  • Backpropping of lower floors must be maintained when formwork is loaded on upper floors to prevent overloading.

Why?

Prevent catastrophic collapseFalsework failure during a concrete pour collapses the entire structure instantly — proper design and inspection are mandatory.
Permit to loadConcrete must not be placed until the temporary works coordinator has inspected and issued a permit — this is the critical control.
Striking too earlyRemoving formwork before concrete has reached the required strength causes structural collapse — cube test results must confirm readiness.
Do Don't
  • Ensure formwork and falsework have an approved design and independent design check.
  • Obtain a permit to load from the temporary works coordinator before pouring concrete.
  • Erect falsework exactly as shown on the design drawings without any deviation.
  • Place falsework props on firm ground with adequate sole plates beneath base plates.
  • Apply release agent to formwork faces before fixing reinforcement inside the mould.
  • Inspect formwork and falsework before, during, and after every concrete pour.
  • Maintain backpropping on lower floors as specified in the propping schedule.
  • Confirm concrete cube test results meet the required strength before striking formwork.
  • Report any signs of movement, deflection, or leakage during the pour immediately.
  • Follow the agreed striking sequence — never remove formwork out of the planned order.
  • DON'T use formwork or falsework that has not been designed and independently checked.
  • DON'T pour concrete without a valid permit to load signed by the TW coordinator.
  • DON'T alter prop positions, bracing, or any element of the falsework design on site.
  • DON'T set props on soft ground without sole plates — settlement causes collapse.
  • DON'T fix reinforcement into formwork without applying release agent to the faces first.
  • DON'T skip inspections — undetected movement during a pour leads to catastrophic failure.
  • DON'T remove backpropping from lower floors unless authorised by the structural engineer.
  • DON'T strip formwork before cube results confirm the concrete has reached design strength.
  • DON'T ignore leaking, bulging, or creaking formwork during a pour — stop and investigate.
  • DON'T strike formwork out of sequence — early removal of supports causes structural failure.

See also: Temporary Works Awareness | Concrete Pour Safety

RAMS Builder

Generate professional Risk Assessment and Method Statements in minutes. 10 document formats, site-specific content, instant Word download.

Learn More