Support for Exterior Masonry Chimney

[Bill J. Hubbell]

-Yesterday's inspection: A masonry chimney has been added to an approximately 100 year old home. It is plumb, straight, solid, with no signs of movement or cracking. I would guess it to be about ten years old. I always recommend a chimney inspection by a qualified Chimney Specialist before using a chimney.
But- my concern is the structural aspect of the chimney. Even though it otherwise appears solid, there is no visible means of securing it to the home. There are no visible straps, guy-wires, ties, etc. It projects about 10-12 feet above the eaves.

I don't have to meet with my client 'til tomrorrow, but am having a hard time finding the codes for this. Can anyone direct me to those, or offer input?

-Hope this picture works- I'm a little green at posting, resolution, etc.- bear with me. If it doesn't, could someone send me the link to the tutorial for pictures?

Thanks,
Bill

[phinsperger]

Bill, Below is what we require here in Ontario. Probably doesn't help you much but maybe its a start.

9.21.4.5. Lateral Stability
(1) Except as provided in Sentence (2), chimneys shall be braced in accordance with Subsection 4.3.2. to provide stability under wind loads.
(2) A chimney need not be laterally braced provided,
(a) no horizontal outside dimension is less than 400 mm (1’3”), and
(b) the chimney extends not more than 3.6 m above a roof or the masonry wall of which it forms a part.

[Marcel R. Cyr]

Some information in Chapter 10 of the IRC might help you out a bit.

And also here in this link might be some usefull information for you.

http://www.bia.org/BIA/technotes/t19b.htm

And here is a very good reference if you have not seen it.

Verifying for anchorage of a chimney is a little difficult and if your concern is how it is anchored, well , mention it or note it to be a reccomended evaluation.

Hope this helps a little.

Marcel

[Bill J. Hubbell]

Thanks Guys-

From Paul's reply (according to Ontario standards), it looks like the chimney could extend as much as 11.8 ft above the highest point anchoring it to the home, without requiring bracing. Also, the chimney would have to be at least 15 inches thick(which it is).
Regarding the presence of wall-ties- (and since our U.S. codes might differ) I think I'll go with Marcel's advice and recommend further evaluation.

But, Thanks Again, Guys ! for the speedy and valuable feedback

Bill Hubbell
Integrity Home Inspection