This part can just be open air
March 21, 2017 4:02 PM Subscribe
Why are windows added in a somewhat haphazard way on skyscraper construction? I've been watching this this as Salesforce Tower is going up in SF, but I've seen it on other skyscraper builds too.
As I was driving into San Francisco this morning, I was looking at Salesforce Tower going up. It is obviously mostly getting built bottom-up in several distinct steps - windows getting added after steps involving the steel frame & cement.
But randomly, there will be a window or two or more missing from a lower floor. On the side facing the Bay Bridge, I counted a randomly missing window on a floor 16 floors below the highest floor with windows (don't worry, I was a passenger, not counting windows while driving).
Here is a recent image from the build where you can see some of these missing windows in the 6 floors below the highest windowed floor, though I would say it's a little worse on the other side.
I've definitely noticed this on other skyscraper builds before, also. Why would they just be skipping some windows here and there?
As I was driving into San Francisco this morning, I was looking at Salesforce Tower going up. It is obviously mostly getting built bottom-up in several distinct steps - windows getting added after steps involving the steel frame & cement.
But randomly, there will be a window or two or more missing from a lower floor. On the side facing the Bay Bridge, I counted a randomly missing window on a floor 16 floors below the highest floor with windows (don't worry, I was a passenger, not counting windows while driving).
Here is a recent image from the build where you can see some of these missing windows in the 6 floors below the highest windowed floor, though I would say it's a little worse on the other side.
I've definitely noticed this on other skyscraper builds before, also. Why would they just be skipping some windows here and there?
Best answer: Another possibility is the glass had to be re-ordered for some reason. It's a pretty precise fit between a frame, which is usually built in place of stick components, and the glass, which has to have a certain amount of "edge bite" to stay in the frame during high winds, but not so much that the frame will break it through thermal expansion of the glass (it's insulating glass, two panes or "lights" separated by a thermal break, and yes it gets hot) or movement of the structure.
Typically on our jobs, the storefront or curtainwall installer builds the frames, then makes a template for each opening for cutting the glass. It's a real hold-up in the process, can take weeks to get glass, each sheet has to be made, be coated in some way, possibly be tempered or laminated with another sheet, etc.
If a piece of glass got mis-measured or broken before installation, well, there you are.
posted by rudd135 at 5:16 PM on March 21, 2017 [6 favorites]
Typically on our jobs, the storefront or curtainwall installer builds the frames, then makes a template for each opening for cutting the glass. It's a real hold-up in the process, can take weeks to get glass, each sheet has to be made, be coated in some way, possibly be tempered or laminated with another sheet, etc.
If a piece of glass got mis-measured or broken before installation, well, there you are.
posted by rudd135 at 5:16 PM on March 21, 2017 [6 favorites]
Response by poster: Those both make sense, though I would have thought for the loading thing the missing windows would be less haphazard (like all in a column), and that seems like a surprisingly large error rate for window mistakes. But I suppose it's probably a combination of those things.
If anyone has any other insights, I'd love to hear them!
posted by brainmouse at 7:58 PM on March 21, 2017
If anyone has any other insights, I'd love to hear them!
posted by brainmouse at 7:58 PM on March 21, 2017
Each floor may have pretty different layouts, which may lead to different windows being useful for loading on different floors.
posted by rockindata at 8:09 PM on March 21, 2017 [2 favorites]
posted by rockindata at 8:09 PM on March 21, 2017 [2 favorites]
"I would have thought for the loading thing the missing windows would be less haphazard (like all in a column)"
But what if you need to bring loads in through the 5th and the 15th floors at the same time? Can't have two cranes operating in the same vertical space.
posted by komara at 7:29 AM on March 22, 2017 [1 favorite]
But what if you need to bring loads in through the 5th and the 15th floors at the same time? Can't have two cranes operating in the same vertical space.
posted by komara at 7:29 AM on March 22, 2017 [1 favorite]
In some cases missing windows can be ventilation for AC units.
posted by Splunge at 4:27 PM on March 22, 2017
posted by Splunge at 4:27 PM on March 22, 2017
This thread is closed to new comments.
My office recently renovated and we had to remove windows on two occasions to bring in large kitchen equipment and construction materials.
posted by magnetsphere at 4:09 PM on March 21, 2017 [9 favorites]