Welding in the Workshop and During Repairs: When a Welding Certificate Is Not Enough and Written Documentation and a Fire Watch Are Required

The short answer: A welding certificate proves that a person is qualified to weld; it says nothing about the fire safety of the location. That is governed by vyhláška č. 87/2000 Sb.: whenever welding, flame cutting, or soldering is carried out in an area containing combustible materials—including materials within building structures and in adjacent areas above, below, and beside the workplace—it is welding that requires special fire safety measures. Under Section 3(2), implementation of these measures must be documented in writing; under Section 3(9), at least two people must generally be present at the workplace; and after the work ends, a fire watch must be maintained for at least eight hours under Section 4(1). In a clean workshop with a steel workbench, basic measures are sufficient—but even there, two additional fire extinguishers are required if the workplace is not designated for welding in the building design documentation.

The certificate covers the welder’s competence; the regulation covers the location

A “welding certificate” is evidence of completing a basic course or training under ČSN 05 0705. Under Section 3(10) of the regulation, welding must not begin if the welder cannot demonstrate professional competence at the workplace—but that is only one of the four conditions in the same paragraph. The other three concern the location: measures specified according to the type and place of work, documented familiarisation of everyone involved with the fire safety conditions, and compliance with those conditions.

Under Section 1(2), the regulation applies to legal entities and self-employed individuals, including a self-employed contractor working at a customer’s premises; under Section 13(2), a private individual acting outside a business context does not have to document the measures in writing. Under Section 1(1), welding also includes thermal cutting of materials using a flame, arc, or plasma, as well as the use of electric soldering irons and petrol blowlamps. Abrasive cutting is not included in the list, but sparks from grinders are handled in a similar way in practice.

When welding takes place in an area with a fire hazard

Under Section 2(c), an area with a fire hazard is a structurally separated or unseparated area containing combustible materials—including materials within building structures—that may be ignited by the technology being used; under Section 2(d), it also includes adjacent areas above, below, and beside the workplace. Before work begins, the conditions in the work area and adjacent areas must be assessed under Section 3(1), including combustible materials in walls and ceilings. If the conditions change, work may continue only after a new assessment. Because Section 2(m) defines commencement as every start-up of the equipment after the workplace has been left, this also applies when returning after lunch. Section 2(k) also identifies a specific risk that may not be apparent even to an experienced welder—combustible insulation beneath the material or concealed pipework. Typical situations include:

• a steel workbench, concrete floor, and no combustible materials within reach — basic measures;
• railings on an insulated façade, near a timber ceiling, or above a suspended ceiling — combustible material within the structure, meaning an area with a fire hazard;
• cutting in a hall above racks of goods — the adjacent area below the workplace;
• an exhaust above a vehicle inspection pit, or repairs to a tank or pipework — vessels of unknown contents are considered a fire hazard under Section 5(17).

HZS hl. m. Prahy described a fire from 2001: while a pipe was being cut away, textiles caught fire behind the wall through which the pipe passed—the incident caused damage of CZK 1.775 million and injured six firefighters.

Basic and special measures: how to determine which apply

Basic measures depend on the type of equipment: a clean area, a safely stored electrode holder, electrode stubs placed in a non-combustible container, and fire extinguishers. Special measures apply in areas with a fire or explosion hazard, including adjacent areas; Section 3(5) lists options such as removing combustible materials, covering them with non-combustible material, measuring concentrations of combustible gases and dust, cooling structures, ventilation, and screens protecting against spatter. For recurring work at similar workplaces, Section 3(6) allows the measures to be specified uniformly in a work procedure. For work at heights of 2 metres or more, Section 5(8) requires a protection zone beneath the welding location, covering at least a circle with a radius of 10 metres—when working on the roof of a hall, this therefore includes the floor within 10 metres of the work location.

Under Section 5(1), a permanent workplace is only one designated for welding in the building design documentation. A welding bay in the corner of a vehicle repair shop is a temporary workplace and, under Section 5(5), must have at least two portable extinguishers in addition to the standard fire extinguishers, including one powder extinguisher with a charge of at least 5 kg. A permanent workplace, on the other hand, benefits from an exemption concerning the fire watch after work is completed (Section 4(3)).

What the written document must contain

The regulation does not prescribe a form; Annex 1 refers to an “order”, while in practice the document is known as a hot work permit. Its required contents can be treated as a checklist:

1. the precise location, definition of the task, and technology used;
2. identification by name of the welders, together with evidence of their competence; the date and time work begins and ends;
3. specification of the measures, the method for checking and documenting compliance, and the names of the responsible persons and those carrying out the measures;
4. the form of the fire watch, the number of people, their duties, and their names—during the work, during interruptions, and after completion;
5. confirmation, including names and signatures, that the individuals concerned have been familiarised with the measures; the firefighting equipment provided; and the person to whom completion of the welding must be reported;
6. the name, position, and signature of the person issuing the permit, together with the date; both parties confirm completion of the required actions and handover of the fire watch by signing and recording the time.

The regulation does not specify who issues the permit. This must be defined in the organisation’s fire safety arrangements under Section 30(2) of vyhláška č. 246/2001 Sb., which include company orders and instructions as well as competence requirements for people entrusted with work that could cause a fire—the footnote specifically refers to vyhláška č. 87/2000 Sb. This is typically the operations or maintenance manager; for work at a customer’s premises, it is a representative of the customer who knows the building. For more details, see our article on fire safety documentation.

Two people and a fire watch: who, for how long, and when it is not required

For welding that requires special measures, Section 3(9) requires at least two people to be present, including the welder. One person is sufficient only if the welder can personally perform both the welding and all fire safety measures. Under Section 4(2), the fire watch is carried out by a person designated in advance whose rights and duties have been specified in writing: continuously during welding; continuously for a specified period after completion or during an interruption; or at intervals defined by the special measures. Under Section 4(1), the minimum period after completion is eight hours. When thermally cutting metals or working in complex spaces, account must be taken of the possibility that a fire may start even later. Eight hours therefore does not necessarily mean standing beside the weld for eight hours—the inspection intervals and the names of the responsible people must be stated in the document. Section 4(3) lists the exemptions: EPS together with a fixed fire suppression system; EPS alone, provided that a person capable of initial firefighting intervention is present; and permanent workplaces where hot particles cannot come into contact with combustible materials.

Workplace and electrical equipment: welders, power leads, and cylinders in a van

Section 7 of the regulation covers electric welding: conductor connectors must be placed on a non-combustible surface; conductors and clamps must not be replaced with metal objects, structures, chains, or ropes; the workpiece must be secured so that current cannot flow along unintended paths; and the equipment must be disconnected from its power source after the work is completed. Under Section 5(11), damaged equipment must not be used for welding. This creates a direct link to electrical safety: a welding machine is an electrical appliance, and both its power lead and any extension leads used during installation work are subject to inspections and testing under ČSN 33 1600 ed. 2 and ČSN EN 50699—a cut extension lead or a cable with insulation repaired using tape is exactly the type of defect that electrical appliance and power tool inspections can detect before a fire occurs. Section 6(27) allows installers with gas welding equipment to leave cylinders in a mobile workshop only under certain conditions: no more than two cylinders in use and two spare cylinders, secured near the entrance, with ventilation and a powder extinguisher containing at least 5 kg of extinguishing agent accessible from outside.

How this fits into fire safety documentation and training

Section 4(2)(f) of Zákon č. 133/1985 Sb. classifies activities involving an open flame or other ignition sources in the immediate presence of combustible materials as activities with an increased fire hazard; regular welding in a hall containing combustible materials may therefore move a company into a higher fire-hazard category. Under Section 6(1), such a company must demonstrably establish and comply with fire safety conditions and may entrust work that could cause a fire only to qualified people. Even a workshop without an increased fire hazard must, under Section 5(1)(c), comply with the technical conditions and instructions governing the fire safety of its activities—vyhláška č. 87/2000 Sb. is precisely such a regulation (Section 24(2) of the Act).

Under Section 38(2) of vyhláška č. 246/2001 Sb., written welding documentation constitutes evidence of compliance with the conditions imposed by specific regulations—the fire inspection authority will request it during an inspection just as it requests inspection reports. Under Section 23, fire safety training must cover the fire hazards associated with workplace activities and the documentation defining the applicable conditions. It must be repeated at least once every two years, or every three years for managerial employees, while an external welder carrying out an activity with an increased fire hazard must receive training equivalent in scope to employee training. We explain how to structure it in our article on employee fire safety training, and who trains whom when work is performed at another company in our article on external contractors.

What not to do

• Do not treat a welding certificate as proof of fire safety — it covers only one of the four conditions for starting work.
• Do not consider a corner of the workshop a permanent workplace unless it is designated as such in the building design documentation.
• Do not issue a general permit “for today” — the document must specify the location, task, names, times, and signatures.
• Do not leave after completing the final weld — the fire watch must continue for at least 8 hours, and the responsible person must be named in the document.

Frequently asked questions

We have a welder with a valid certificate. Do we need anything else?

It depends on the location. The certificate covers one of the four conditions in Section 3(10) of the regulation; in an area containing combustible materials or a combustible structure, written special measures, a second person, and a fire watch are also required.

Who signs the hot work permit?

The regulation does not specify a particular position; Annex 1 requires the name, position, and signature of the person who issued the permit, while the organisation’s fire safety arrangements determine who that person is. At a customer’s premises, the permit is usually signed by the customer’s representative who knows the building.

Does an eight-hour fire watch mean standing beside the weld for eight hours?

Not necessarily. Under Section 4(2), the post-work fire watch must be carried out continuously or at intervals specified by the special measures; the intervals and names of the responsible people must be included in the document. However, the requirement is not waived unless EPS, a fixed fire suppression system, or the exemption for a permanent workplace applies.

I am self-employed and weld at customers’ premises. Does this apply to me?

Yes. Under Section 1(2), the regulation also applies to self-employed individuals. Recurring jobs of the same type may be covered by a standard work procedure; the location, names, and times must be completed separately in each document.

Sources for this article

• Fire safety – a service provided by SOHE.
• Fire safety documentation – where hot work permits belong.
• Employee fire safety training – content and required intervals.
• External contractors and self-employed individuals in the workplace – who is responsible for training whom.
• Vyhláška č. 87/2000 Sb. – fire safety conditions for welding; Sections 1–7 and 13, Annexes 1 and 2.
• Zákon č. 133/1985 Sb. – fire safety; Section 4(2), Sections 5 and 6, and Section 24(2).
• Vyhláška č. 246/2001 Sb. – fire prevention; Sections 23, 30, and 38.
• ČSN 05 0705 (training and basic courses for welders); ČSN 33 1600 ed. 2 and ČSN EN 50699 (inspection and testing of electrical appliances).
• HZS ČR: Podmínky požární bezpečnosti při svařování – guidance from HZS.
• Požáry ze svařování (HZS hl. m. Prahy, 2003) – a case from 2001.

The legal position was verified as of 28 August 2026: according to e-Sbírka, vyhláška č. 87/2000 Sb. has been in force since 1 July 2000 without amendment; Zákon č. 133/1985 Sb. in the version effective from 30 August 2025, and vyhláška č. 246/2001 Sb. from 1 January 2026.

This text is for informational purposes and does not constitute legal advice. The specific welding arrangements must be established according to the actual operation, the manufacturer’s documentation, the operating environment, and the risk assessment.

Do you weld in a workshop, on installation jobs, or during maintenance, yet your fire safety documentation does not mention it at all? As part of our fire safety documentation service, we will prepare instructions and a hot work permit template, add the topic to your employee training, and inspect welding machines and power leads during electrical appliance and power tool inspections. Send us a no-obligation enquiry or email info@sohe.cz.