Ask a safety officer: Gas fitter qualifications, venting material & mobile camp requirements

Mobile Trailers

From permit questions to inspection inquiries our gas safety officers are asked hundreds of questions each month. Most are fairly generic but sometimes they hear very specific questions repeated again and again. We have rounded up three questions posted by gas fitters working in BC.


I am a Class B gas fitter, am I permitted to work on a direct-fired make up air unit?

A Class B gas fitter qualification issued after April 1, 2009 permits the individual to perform the installation or alteration of the following gas systems under an appropriate permit:

  • (i) an appliance with an input of 120 kW or less that displays a label or mark as follows:

(a) a certification mark;

(b) an approval mark issued under section 10 of the Act;

A class B gas fitter qualification issued prior to April 1, 2009 permits the individual to perform in addition to the above;

  • the installation or alteration, under an appropriate permit, of:

(i) a fan assisted appliance or a natural draft appliance, and

(ii) an appliance, other than an appliance referred to in paragraph (a), with an input of 220 kW or less,

This means that provided the individual can demonstrate training and has the appropriate tools and equipment to do so, they can perform the commissioning or servicing of a direct fired make up air unit up to 409,000 btuh (120 kW) for certifications issued after April 1, 2009, and up to 750,000 btuh (220 kW) for certifications issued prior to April 1, 2009.

Due to the safety concerns involving direct-fired make up air units, a commissioning approval is required as per section 26 of the Gas Safety Regulation. At the time of the commissioning, the individual must demonstrate knowledge of the equipment and its operation to the gas safety officer.


Can System 636 PVC or CPVC venting material be directly buried?

No. At this time manufacturers of System S636 PVC and CPVC venting material do not provide guidance in their installation instructions for direct burial of this venting material. Venting material must be installed in such a manner as to allow for free movement of the piping system so that for expansion and contraction due to temperature fluctuations can occur. Direct burial would directly conflict with this requirement. The installation instructions also require that exhaust piping systems be protected from freezing.

For more information see our gas plastic venting directive.


What are the on-site permitting requirements for a relocatable camp structure?

Mobile camp buildings (i.e. physical structures made up of multiple certified relocatable structures) are considered an appliance under the Commercial Installation Fee on the current gas fee schedule.

The permit to be obtained will be a permit for the total BTU (British thermal unit) per mobile camp building. Each separate building will be treated as an appliance (total BTU’s under shared roof, or per riser, etc.) as indicated under the commercial installation fee section of the current gas fee schedule.

If the relocatable structure is not certified, a commercial installation permit is required and a fee per appliance will be charged.


Do you have questions related to gas appliances, permits, certification or compliance/enforcement? Comment below and get your question featured in our next post!

Share article on