The Technical Standards and Safety Authority (TSSA) has issued an advisory clarifying the requirements for the foundations of residential or small commercial standby generators with a capacity of up to 26 kW and fueled by natural gas or propane.
According to CSA B149.1-20 Natural Gas and Propane Installation Code, these generators must be installed on a firm, level foundation and in accordance with the manufacturer's instructions.
Manufacturers often require, recommend or permit installation on a poured concrete pad, a prefabricated concrete slab, compacted soil, gravel, patio stones or other similar materials. TSSA will consider an installation compliant with clause 7.2.1.6 if the foundation meets the requirements or recommendations outlined in the manufacturer's instructions.
If the manufacturer’s instructions are unclear, do not specify foundation requirements or provide recommendations only, TSSA will deem the installation to be compliant with clause 7.2.1.6 if the foundation meets the following requirements:
- It is composed of compacted crushed gravel or limestone base and a non-combustible platform (such as patio stones or a concrete slab); and
- The top surface of the foundation is at least 2 inches above the surrounding ground surface.
Please refer to the advisory for full details.