Everyone loves a nice roaring fire to stave off the cold from time to time, but nobody likes it when the ceilings around their chimneys start dripping water. Here’s the lowdown on why such problems occur and some tips on how to correct them.
Chimneys, stovepipes and other protrusions usually exit the roof through holes in the underlayment and slope layers. Although these planes are cut to fit, there’s no such thing as a perfect match, and the gap can expand as the roof undergoes thermal contraction during colder weather. Any ice dams that form may also allow water to enter at a faster rate.
Due to this combination of factors, some Mount Pleasant roofing eventually begins to leak around chimneys, and because these fixtures go through the attic and ceiling as well, the water can travel all the way down into the interior of your home. If this occurs, your insulation may become wet, and your building’s energy efficiency could decrease as a result.
Many home designers hope to prevent these problems by placing chimneys in the center of the house so that they exit the roof at the highest point. Water naturally follows the path of least resistance, so using gravity to divert moisture away from gaps is an effective method of leak prevention. Combined with properly installed flashing and other materials, good chimney design can prevent a large majority of potential leaks.
Unfortunately, this concept won’t do you any good if your home already has a chimney at the low edge of a roof.