Exit Strategy: The Case for Single-Stair Egress • Hacker News Board

Re: Exit Strategy: The Case for Single-Stair Egress

#91

Post by jeegsy » Sat, May 18, 2024, 3:32 AM UTC

stuaxo wrote: post #55

TylerE wrote: post #31

Earlier quoted context omitted.

Europe is also where Grenfell Towers happened.

The tower itself is concrete, so the building itself wasn't the problem. Lack of maintenance or fitting of sprinklers and firedoors was: the residents had been asking for a while, but Kensington council cares more for its richer residents, so instead what happened was plastic cladding was fitted to make the richer residents not have to have an old tower block spoil their view.

> the richer residents not have to have an old tower block spoil their view.

I've seen this particular point made a couple of times. Can someone explain how the cladding used affects the view from other buildings?

Re: Exit Strategy: The Case for Single-Stair Egress

#92

Post by tommoor » Sat, May 18, 2024, 7:41 PM UTC

card_zero wrote: post #48

twelvechairs wrote: post #36

Earlier quoted context omitted.

These ('scissor stairs') are an important part of the discussion here. They are allowed (or counted as two separate means of exit) in New York, Australia, Vancouver, etc. but not permitted (or counted as one means of exit) in most of the rest of the USA, the UK, etc. For a high rise building they don't take up much more space than a single stair and can play an important role in the structure of the building also.

Also you can feasibly climb over the rail at certain places to reach the other stair, which could be useful in the event of multiple blockages, and adds interest to action movies.

There is a concrete well, they are completely fire isolated in this case

Re: Exit Strategy: The Case for Single-Stair Egress

#93

Post by tommoor » Sat, May 18, 2024, 7:42 PM UTC

9991 wrote: post #18

tommoor wrote: post #12

My 30+ story building has two concrete stairwells wrapped around each other, which seems like a super efficient way to achieve the current legislation

Sounds like a death trap.

There is a concrete well, they are completely isolated from one another

Re: Exit Strategy: The Case for Single-Stair Egress

#94

Post by tommoor » Sat, May 18, 2024, 7:42 PM UTC

colinbartlett wrote: post #24

tommoor wrote: post #12

My 30+ story building has two concrete stairwells wrapped around each other, which seems like a super efficient way to achieve the current legislation

They are called scissor stairs and it's very common here in newer buildings in NYC as well. Though I believe it's only permitted in buildings 12 stories are less? It always seemed very space efficient -- separated by concrete fireproof walls and taking up the same vertical space.

Yes, this is a new building in NYC ;-)

Re: Exit Strategy: The Case for Single-Stair Egress

#95

Post by dredmorbius » Wed, May 22, 2024, 1:30 AM UTC

rtpg wrote: post #90

pjc50 wrote: post #64

Earlier quoted context omitted.

It's much easier to pour concrete than do all that welding, and steel is not as fire resistant as you might expect.

I was just thinking of bolts. I mean we're talking about the staircase right, not the part of the building that actually holds up the entire structure. But I might be vastly overestimating this. My previous appartment was in a 3-story building, and my impression was that the entire staircase was bolted together (and it was on the outside of the building).

It's less that stairwells need to support the structure than that stairwells need to survive the destruction of the structure, something concrete does remarkably well.

Not turning into an oven is another feature. Heat conductivity of concrete is far lower than that of steel.