The chimney shown at right is a classic example of a problem chimney which is too short. How short? Consider that a stove located on the first floor of this ranch house enters the chimney at about the height of the window air conditioner that you can see next to the chimney. The total height of the chimney from that point to the termination is less than 8 feet. In addition, the chimney is built at the low side of the roof and does not meet the standard of “two feet higher than anything within 10 feet”.
An Extend-a-Flue™ Cast Classic™  chimney extension would certainly help a chimney like this by adding over 30% to it’s height. It would also bring the chimney up to the height required by code. However, this chimney may need even more help than that.

Experts Opinion: This chimney should be built at least two feet higher with masonry and then be fitted with an Extend-a-Flue chimney extension for a total height of 13+ feet.

This chimney on the right has two problems – it is too short and it is too close to the taller part of the home. Wind induced downdrafts are almost surely a problem for this chimney.

Experts Opinion: This chimney may have a reasonable height, but is too close to the other roof line and most likely doesn’t meet the “two feet higher than anything within ten feet” rule. Adding an Extend-a-Flue chimney extension would increase the height, help it clear the other roof line and allow it to meet code requirements.



Each of these two chimneys shown on the right have two flues that are so close together, standard chimney caps won’t fit. Surely the right hand chimney cap in the top photo won’t last long. This creates a hazard for anyone in close proximity on a windy day!

Since the flues are the same height and so close together, smoke crossover is almost certainly a problem for these chimneys.

Experts Opinion: A Boost-a-Cap by Extend-a-Flue will allow for the proper installation of the two chimney caps and prevent smoke from crossing over from one flue to the other.