Suppose a tree about 80 feet tall falls and hits a modern office building about 15 stories tall. How much damage would it do?
It may take out some windows but I doubt it would do anything to the structural integrity of the building. If the exterior is concrete, or masonry, or steel a tree tipping over onto it won’t do much except maybe some cosmetic damage.
If it lands on the roof however it could easily damage the roofing material and cause leaks.
Agree with Hampshirein general. To dig a bit deeper.
How far does the tree fall before it hits the building? e.g. if the tree’s base is immediately adjacent to the building and tips over just a few degrees before the crown is leaning on the building that’s different from the situation where the tree’s base is 75 feet from the building and it tips over almost the full 90 degrees before the crown finally meets the building.
In the former case it might not even break glass if enough of the crown ends up leaning on support pillars between windows.
In the latter case the crown might enter the building at high speed just above the 2nd floor and bend or crush a short section of the second floor. It’d suck big time to be standing right there when t happened. Probably wouldn’t hurt for more than a second or so.
Either way, the damage will be trivial in the context of the whole building.
While there probably would not be any structural damage, the dollar amount of damage might be much higher than if the tree hit a house. Replacing windows and tall building exterior facing can be quite expensive - might need to be custom ordered/made.
If this happened in a hurricane, the wind-driven rain would probably cause much more damage than just the broken glass.
80 foot tree vs 15 story building. Building will be in the 150+ feet tall so no roof damage. Depending on the construction of the building damage from almost none to a lot of broken glass. If the angle was exact maybe a broken sprinkler or two so some water damage.
I’ve done a few restorations on houses damaged by tree fall. The big difference here is obviously height. A limb or trunk coming down on a roof from 60’ can bust a truss or two depending on how it lands, sheathing and roofing material will take a beating. Not going to be an issue with tall buildings.
The dramatic damage is from limbs perpendicular to the structure punching through to penetrate deeply. You would still get this a tall building. The envelope of many commercial tall buildings is not load bearing so there is unlikely to be any serious damage but a twenty foot limb punching through the walls is going to be pretty exciting.
Thanks, everyone.
Would it make a difference if the building were very narrow, like Baltimore’s Bromo-Seltzer Tower?
Bump
Maybe some broken glass or the clock damaged. Building would still be standing.