Smoke Testing

To perform a smoke test a large smoke pellet is placed into a warmed fireplace or woodburner. The smoke should begin to rise up the chimney and not leak into the room. Once the pellet is half way through the burn it is important to go outside and observe the smoke exiting the chimney pot and examine the full length of the chimney. If the pointing on the chimney stack is damaged, smoke could be observed seeping through the gaps in the mortar. Another vulnerable spot is the flaunching at the base of the chimney pot. Gaps may appear and the smoke should be seen exiting the base of the chimney pot as well as the pot. Smoke can sometimes leak from the fireplace if the opening is too large or the room has inadequate venting. Cold air can drop down a chimney and cause a downdraft or a reverse draw. This can usually be remedied by heating the chimney before a smoke test. The smoke test is a good guide to assess the draw on a chimney and pick out flaws in the flue.