See what experts say is the probable sequence of collapse at the FL condo tower | Hacker News Reader

See what experts say is the probable sequence of collapse at the FL condo tower

miamiherald.com

18 pointsZeljkoS10 comments

This exemplifies how housing is a depreciating consumer good, not an "investment" like owning land. But the time-scale of depreciation is on the order of human lifetimes, and since humans are generally only exposed to renovated surface layers (floors and kitchen cabinets), it is rare to get an intuitive understanding that the buildings and foundations are depreciating.

Pools have huge mass. If that much mass shifts, the effects on surrounding ground are extreme. Here in OZ people often say empting a pool is a suicide move: the concrete pops out of the ground as the resistance built up in the surrounding ground pops.

A big condo complex pool draining rapidly would be a hell of a trigger.

Don't pools get emptied and refilled on occasion? How is the water cycled otherwise? Or does the same water just get cleaned and kept in there?

> Don't pools get emptied and refilled on occasion?

It is sometimes (normally, at several-year intervals) necessary to drain pools due to chemical conditions, but even them the advice is to only partially drain certain pools in any conditions, and any pools where there is high groundwater, because of the risk of popping and other structural damage.

> How is the water cycled otherwise?

Continuously.

> Or does the same water just get cleaned and kept in there?

Yes, it is filtered and chemically treated in place.

It's a slow moving problem. Even in the swampiest part of the bayou you can drain a pool and spend a few months doing maintenance. In-ground objects lifting out requires certain soil conditions to happen at all depending on the properties of the object. Internet comments are likely not representative of your local conditions.

I've never emptied my pool -- in general you only need to empty a pool for certain types of repairs. The water is cleaned by the pool filter.

Images from an inspection show rusty water leaking out of the parking garage roof. They mention "standing water". So the reinforcement steel was in various stages of decay.

Yep, pools are more like boats when they are empty. Here are some pictures https://sandiegoapprovedhomepros.com/pools-popping-out-of-th...

Reddit has a better sequence -

https://www.reddit.com/r/CatastrophicFailure/comments/o7s500...

Looks like people are focusing on the current timeframe and looking backward toward the recent past for clues.

When these were being built it was with quite an unexpected boom too.

To complete the other half of the equation you need to start with the construction financing before the condo project was built, and follow the money from there forward.

It was widely circulated that not every hi-rise was really being constructed the way it was supposed to be.

I guess it would be kind of similar to how during a software boom the engineering and grunt work are subject to more frequent pivots because of boom conditions, everything is rushed, and not everything is as robust as it could be before it ships. When anybody can, and is, leaving at any time to go to alternative employers against deadlines for any little reason you end up with some projects having all the good people and others having none. Plus money can run short and more capital may need to be injected on an emergency basis, introducing financial incentives that may not perfectly align with those in the original deal.

Only the top upscale projects were designed to best survive in the face of a direct hit from a monster hurricane.

None of the local construction workers at the time would have ever let their grandparents move to one of the ones designed to be affordable to owners on a fixed income.

If lots of fixed-income retirees buying these newly-built units had good financial advisors they probably wouldn't have wanted them to move there either.

Expenses always go up so these buyers needed to be sold to very persuasively, directing focus completely away from that type of math. Salespeople who could accomplish this against the raging inflation of the 1970's were like gold to the developers.

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