Does this chimney shape serve a purpose?

Esteemed colleagues,

I recently came across this chimney in a home that was built in 1911 in Eastern PA. When the chase entered the attic, it turned, as seen in the photos, and straightened before it exited through the roof.

The man who bought the house to flip, said he has seen several similar chimneys in this particular town, but nowhere else. Does this structure have a purpose, or did someone miscalculate in the plans?

Thanks for the help. Sorry the photos are not better, but there is a window next to the chimney. It was an unusually bright day when I took the photos. I tried to keep the window out of the photos.

The tank in the photo is an expansion tank from an old steam boiler that at one time heated the home.

Dean Conrad

One of the main reasons why chimneys are offset is so that they exit on the exterior in a more aestheticlly location. The location of the fireplace on the interior is likely off center to the length of the side of the home.

Thanks, Scott.

Have you seen similar chimneys in Philadelphia? There was no fireplace involved here. It was a straight run from the basement, where a steam boiler was originally installed. The home now has oil heat.

The current owner, who has flipped a number of houses, and has been through many more, thought the chimeny was a great curiosity. I tokd him I’d post some photos and try to get an explanation.

Thanks again.

Often chimneys back then were constructed deliberately in an offset fashion because the mason wanted it to exit the roof at the ridge so no snow would built up behind it or to the backside of the house for appearance reasons.

However, those type of chimneys had no liner and often were built with an inferior mortar creating additional problems.

An N.F.P.A. Level 2 chimney inspection is recommended.

Does anyone know how much of an offset is safe? How is the load transferred, other than straight down? There were some 1X boards on the belly side of the offset that appeared to have been installed when the chimeny was built, but seemed to add nothing to the structural integrity of the chimney.

This is the first chimney I have seen with such an offset, even though I see many older homes.



When my mother had her roof redone they knocked off the chimney tops as they are no longer used and she did not want them anymore. While in the attic I noticed the chimney comming from the kitchen to the roof was offset like this. At first I thought that it was leaning from when it got taken apart up top and was worried that it may fall into her kitchen. When I got closer I realized that it was actually built that way.

I would definitely recommend an inspection. At that age, it is likely unlined, with loose mortar, possibly needs a metal liner to make it safe.
John Kogel