Chimney cracked because of tornado?

[Bobby Jim]

I have a house that I’ve inspected on a pier and beam foundation. A tornado was close but the building was not damaged (there was no shifting of the foundation, no shingle creasing/tearing, all soffit/fascia is tight and the building columns and walls are plumb) the chimney brick above the roof line is not cracked, the chimney brick in the attic is not cracked. The chimney brick in the interior of the building is cracked in several places. Is there ANY WAY that the wind forces from the tornado could have caused the chimney to crack in the interior of the home? I can’t think of how but homeowner insists the tornado was the cause of the cracking.

[Les]

yes the tornado could have been culprit.  the house envelope can and will rack with the storm forces and it can crack a chimney like that.  because it is interior only the racking would only impact interior brick.  tornadoes are much like explosions - you can believe anything. 

[Bobby Jim]

Thanks Les, should I then expect to see the building racked? Is there any other corroborating evidence I should have looked for?

[Les]

any interior indicators of racking:  interior doors, wall corners at ceiling, and window openings.  location of cracks below the roof line on the chimney.  

[Jim Katen]

The building frame might also have distorted and then sprung back to its original position. Just because it racked doesn't mean that it stayed racked. 

[Les]

31 minutes ago, Jim Katen said:

The building frame might also have distorted and then sprung back to its original position. Just because it racked doesn't mean that it stayed racked. 

True.  If it was racked enough to crack chimney it is pretty likely there would be other clues.  I have seen that phenomena when there was an explosion on the first level of a house with a basement.  I have no experience with a house on crawl or slab.  

Extreme event(s) require a little more investigation and experience than a typical home inspection.  

Could be a simple masonry issue and nothing exotic at all.

[Marc]

I doubt the crack is a result of direct impact on the chimney by the wind, since a large portion of the chimney is indoors.  As others have said, the house can tolerate some movement but the brick is unforgiving and will crack should the house move and generate enough force against the chimney at the roof level.

I think the most important question here is whether the flue liner is also cracked.

Just my two-bits.

[Les]

is the first photo the lower left of the last photo on the hearth?

[Bobby Jim]

On 3/5/2020 at 6:29 AM, Les said:

 

On 3/6/2020 at 9:25 AM, Les said:

is the first photo the lower left of the last photo on the hearth?

Yes it is. Another note...all the cracking is in the bottom few courses of brick

[John Ghent]

"I have a house that I’ve inspected on a pier and beam foundation."

That's probably something to consider as a possible cause.  I have a fireplace that has settled, (cracks in the lower courses but not higher up) because it was built on a garage slab without a correct foundation.