Re: Condo Building Collapse in Miami
 

Just a general observation about modern multi-storey buildings, not just this one, but all that have multiple levels of parking below ground and other below ground levels. Presumably, an inevitable result of how expensive land is in many of these places.

I’ve been reading about the history of the adjoining property, 8701 Collins. In 1951, a hotel was built on it, designed by a well known Miami architect, classic mid-century modernist, unfortunately it had no preservation order on it, it was demolished in 2014 to make way for the huge luxury condo block that is there now - the one that residents of the collapsed building complained about because of construction vibration & possible damage to their building.

Anyway, this 1951 hotel had plenty of parking onsite, but just ground level. No multiple parking levels beneath the building. I’m guessing that was not yet a thing in southern FL in 1951. It seems to me that parking levels beneath a building introduce all kinds of water penetration dangers - especially by the sea in Florida, where it can rain a LOT in a very short time, with inadequate storm drains and seawater seeping upwards, too.

Re: Condo Building Collapse in Miami
 

Here is a 1957 postcard of the Biltmore Terrace Hotel, 8701 Collins. On this site is the massive new condo block built in 2019. The site where the collapsed Champlain Tower will be built in 1984 (?) is hidden just behind the hotel. Note how all the buildings on the seafront in Surfside, at that time, were low rise, two or three floors at most. (The hotel being on the northern border of Miami Beach, the buildings in the background being in Surfside.) To tell the truth, I’d prefer a holiday there in 1957 to 2021 ..


https://cimg8.ibsrv.net/gimg/british...15a9bd4d2.jpeg

Re: Condo Building Collapse in Miami
 

I watched that video and several others cleverly provided by YouTube (it's nice to see YouTube's cleverness being used for good, and not just to promote conspiracy theories!). Did you notice the annoying music? At times, it was drowning out the dialog.

Regarding the planters ... I worry now when I see these new 'eco friendly rooftop gardens'. It has become fashionable to put 'greenery' on rooftops for both aesthetic and environmental reasons, but I worry that they are not going to deal with drainage properly and run into big issues down the road.

There are a few issues with any attempt to 'make use of' a roof (or pool deck, or whatever); first, once you cover the surface with plants, you run the risk of introducing damaging water ('vegetation' is a uniquely damaging beast, since most plants require soil to be in a permanent state of dampness); but secondly, any attempt to cover the 'utility' part of a roof (the waterproof membrane) means you can no longer visually inspect it. So any mistake during construction, or deterioration over time, is much more difficult to detect (as an aside, I note that many waterproofing systems are designed by smart people, but may ultimately get installed by a construction worker who is out there in 100F weather rushing through the job to get done as quickly as possible!)

I even worry about solar panels in this regard; mounting solar panels on a roof requires you to break through the waterproof membrane of the roof. Of course, the 'posts' used are designed for the purpose, but still - making dozens of penetrating holes in a roof to support panels is simply asking for trouble if any one of them is not installed correctly. With a typical sloped roof over an attic, you just have to keep an eye on the attic space but they also install solar panels on flat roofs, which are much more difficult to inspect. There's an article here specifically addressing concerns related to flat roof solar - https://www.everguardsolar.com/is-ba...our-flat-roof/ . Interestingly, they are advocating using weights to 'hold down' the panels, rather than drilling holes in the roof ... which sounds great until you get 100-year storms with super high winds! Solar panels look awfully similar to wings when it comes to wind!

Re: Condo Building Collapse in Miami
 

Me too. It would be a lot cheaper. :lol:

Re: Condo Building Collapse in Miami
 

I always fancied a trilby hat, and clutching a pipe between my teeth.

Re: Condo Building Collapse in Miami
 

https://cimg7.ibsrv.net/gimg/british...88b1670133.jpg


BTT soon :nod:

Re: Condo Building Collapse in Miami
 

From the last engineer's report, it seems that waterproofing on the pool deck - on which the planters were constructed - was completely absent despite being present on the plans. Plus the water intrusion through that deck into the garage was actually visible; it's just that the HOA ignored the problems for years. But if the columns were affected by water from the planters, then that would likely have been hidden given the way the planters abutted the columns.

I had also thought about the solar panel issue. The property abutting mine got solar panels installed last year so I was able to watch the installation. I've been up on my roof and it all seems rather slapdash to me.

Re: Condo Building Collapse in Miami
 

I've been wondering about these roof top gardens for a few years, some even have trees, just seems like an unnecessary risk having plants that need watering on roofs, relying on waterproofing materials, that have failed in the past causing leaky buildings, but they are built differently.

Things like this pool make me nervous too.

https://cimg3.ibsrv.net/gimg/british...f08cd6cd71.jpg

Re: Condo Building Collapse in Miami
 

My earlier concern - that actual installation of all this stuff is done by construction workers who may cut corners and have no idea what the 'design intent' of the work was - is compounded by, as you say, dishonest contractors and building managers who will simply omit materials altogether if they think it won't get noticed. For this reason I'm very supportive of the notion of 'city inspectors' and the associated permit process. They made my life hell when I was doing a condo conversion in San Francisco, so I never thought I'd say a kind word towards them, but they are one of the few people who have the power to catch this stuff. Ideally, there should be an inspection and sign-off at every 'demonstrable' stage in the process; nothing should ever be covered up before it has been inspected.

The house I referred to earlier - the one where the deck had to be replaced for $40k thanks to our ill-advised over-watering of planters - also had a private roadway that was cracking up soon after we moved in. Turns out, there was absolutely no re-bar in the concrete, and we had to have the whole thing re-done at considerable expense. The story goes that our builder originally planned to put 5 homes on the land, but two of the permits got pulled and he was only allowed to build 3. So he ended up cutting a whole lot of corners to try to lower his costs, especially on 'shared elements' like the road.

Re: Condo Building Collapse in Miami
 

You just need a competent engineering firm, like Bechtel, but they almost surely won't waste their time on such little projects.

Re: Condo Building Collapse in Miami
 

I can remember all the jokes about turning up on the Costs to find your hotel still under construction.

I know where I am the building department is only about 50 years old and apparently back in the day a Bottle of Whiskey would get most things past.

I wonder what the perceived life expectancy of these buildings was and is.

Similar to bridges and the like, they have been standing there for decades and there is a presumption to think of them as an asset, coming to the end of their life they are more likely a liability.

Presumably the land here is valuable so the site will be cleared and rebuilt.

Re: Condo Building Collapse in Miami
 

It's 40 minutes long, but he goes into pretty good depth going back to the original drawings and design back in 1979/1980.

Re: Condo Building Collapse in Miami
 

I finally got through the entire 40 minutes! Very interesting. And no annoying background muzak!

Basically, a lot of the video focuses on - of all things - the giant planter boxes that were placed on the pool deck, and the addition of some palm trees and sand years later (which were removed not long ago). Looks like the structural design of the building did not allow for the weight of these very heavy items.

For anyone who really understands these things, there's a fair amount of discussion about a 12" 'step down' in the pool deck slab that was in the original design in 1979 and then removed in a revision to the design in 1980. I don't see the purpose or significance of such a drop. Video discusses this starting at 25:45 mark.

Re: Condo Building Collapse in Miami
 

The significance is that the original design - in order to incorporate a 12" step down to the pool area - had a number of beams between posts where the step down was. When the design was revised to remove the step down, the beams were removed. This architect's contention is that that removal caused a structural weakness in the building as those beams were in the original design not only to achieve the step down, but also to support the weight of the planter boxes and to deal with the fact that columns in that area were only 12" x 16" as opposed to 24" x 24" elsewhere at the lower levels. He actually contends that he is somewhat surprised that the collapse didn't occur until 40 years after the building was built. He also mentions that the design as sailing close to the wind in other respects, such as that the loading of the pool deck was at 100%, which doesn't seem sensible when taking into consideration weathering of concrete over time.

Re: Condo Building Collapse in Miami
 

I got all that, but what I was wondering was, why would you a) want a 12" step down to begin with, and then b) why would you want to eliminate it? Perhaps the step-down was an unintended consequence of two different 'sub-parts' of the design coming together, and some bright spark later decided, "hey, we could simply eliminate that if we ... ". That is - maybe the senior team designed the building structure, while the junior team designed the pool deck/parking, and the two designs came together with a 12" difference that required a step-down; someone then reviewed the whole thing as a whole and decided it would be a whole lot easier/cheaper to equalize the two areas, without realizing the structural impacts. Very scary.

It certainly highlights the risk of 'minor' changes made to established plans. The video creator makes the point that revisions often don't get the review/scrutiny that the original design gets.