masonry chimney used for bearing support
1mancrew
| Posted in Construction Techniques on
Could anyone tell me when (if ever) it is appropriate to take advantage of some part of a masonry chimney for use as support. This would include creating a pocket for insertion of one end of a header, or attaching a stud wall directly to the brick or block for increased stability. My chimney has two ceramic flues, both with stainless liners for use of a woodstove and furnace/hot water tank. There appears to be plenty of brick surrounding these flues. The chimney is in the interior of the house, so the footing cannot be disturbed by frost heave. I don’t really expect that the chimney will drift and thus move framing with it, but perhaps my thinking is incorrect. Thanks
Replies
It is specifically not appropriate to use a chimney to carry other loads unless it was engineered for such (and most likely it wasn't).
It's pretty common in Northern New England to have an old house with a chimney that supports (sometimes even houses) a few beams.
Sometimes you see char marks on the beam, or it seems heat damaged. Usually a 100+ year old house has had a few chimney fires. With a good intact flue liner that shouldn't be a problem, but it is a concern.
Basically, it's a judgement call -- was the chimney designed to carry the load? The old ones were, more or less, though perhaps no one calculated the engineering loads.
More to the point, the code enforcement officer *really* likes you to replace this setup with other support. I think beams supported by the chimney is grandfathered, but the design is not smiled upon. So check the engineering, and check with your code officer, who will ultimately be the one to let you do it or not.
Edited 5/27/2002 8:08:31 PM ET by Chaos Dweller
Likely the inspector will do as mine has and refer to CABO (or similar) "1001.4 Additional Load. Chimneys shall not support loads other than their own weight unless they are designed and constructed to support the additional load."
From the esthetic point of view - - the central beam in our house in embedded in this stupin 3 foot by 6foot concrete block with brick veneer chimeny set in the wall between the living room and the kitchen. IF the stupid beam had have been set where it should have been, i conceivably could have convinced my husband to remove the huge ornamental chimney completely, as there is now only a gas fireplace hoooked in, which could have discharged through a small chimney. As it is, this monstrosity takes up 18square feet of space in a house which is only 900sqft to begin with. Given that the ceiling is only 7'10" to begin, and this beam sticks out of the ceiling by 3", guess why i hate this house.
Thanks for your responses. To be honest, I was not that keen on using the chimney for support, but it would have made things somewhat easier for me, for my particular situation. I don't doubt that the chimney could handle the load I would be transferring to it, but the last thing I need right now is to have to re-do the work if it does not meet code. Alas, I wish that I could go back to when I started this remodel, and yank the whole fireplace/chimney...it is huge...so I understand the comment about the small house being dominated by the fireplace.