The Canadian Standards Association is a non-profit association that develops safety, health and environmental standards for Canada. The standards it has developed for wood stoves can be found in CSA-B415.1, and include emissions, minimum installation clearances, floor protection and standards for flue pipes. Although it doesn’t recommend installing uncertified stoves, CSA has also developed standards for them, which can be found in the CSA solid fuel installation code, CSA B365. Rules for installing uncertified stoves are very complicated.
In Canada, emission levels for wood stoves must equal or exceed standards set by the US Environmental Protection Agency (EPA). Stoves certified by the EPA burn pollutants found in wood smoke before they leave the firebox, and can reduce emissions by as much as 90 percent. Non-catalytic stoves manufactured on or after July 1, 1990 can’t emit more than 7.5 grams of smoke per hour (g/h), and catalytic stoves are limited to no more than 4.1 g/h. Look for a lower g/h rating on the white EPA label when shopping for stoves.
Certified stoves are labeled with information showing how much clearance they need from combustible materials. Uncertified stoves don’t carry this label so larger clearances are required for them because nothing is known about how they’ll perform. Allow 48 inches of clearance for an uncertified radiant stove and 36 inches for stoves with sheet metal jackets. Clearances can be reduced on certified and uncertified stoves by permanently mounting a sheet-metal, brick, stone or ceramic tile shield to the wall behind the stove.
Even though certified wood stoves won’t overheat your wooden floor, you still need to install a floor pad to protect the stove from live embers that might fall out of the stove. Construct floor pads from sheet metal, mortared brick or grouted ceramic tile. The floor pad should extend at least 18 inches in front of the stove and 8 inches on the sides and back. Requirements for uncertified stoves vary depending on the height of the legs.
The CSA installation code specifies that the flue pipe should be as short and direct as possible and can’t exceed 10 feet in length. Supports are required every three feet of the horizontal length, and a minimum of three screws is needed for each joint. No more than two 90-degree elbows are allowed, and 5-, 6-, 7- and 8-inch diameter pipes must have a 24 gauge thickness. Pipes can’t run through combustible floors or ceilings and there must be a minimum 18-inch clearance between the flue pipe and any combustible materials unless you install shielding. Galvanized pipes aren’t allowed because they can release dangerous gases when the coatings vaporize.