Trapdoor for spiral staircase

[Theo Markettos]

Bit of a long shot this one, but...

I'm looking at designing a spiral staircase (for a new-build). For various reasons it needs to be possible to separate the floors the staircase links, so I'm thinking of having a trapdoor that fits into the gap in the ceiling formed by the staircase. The door would be hinged and counterweighted, on a pulley controlled by a handle somewhere, tight fitting and fairly heavy (for sound and thermal insulation), with a bolt to lock it. It wouldn't be moved very often (once a week maybe), otherwise staying fixed open or fixed closed.

Obviously such a thing could be built from scratch, but does anything like this already exist? Is there anyone who specialises in the building of trapdoors or similar, who'd be able to give me advice on whether this is a silly idea or not, or suppliers of components?

Thanks Theo

[dom]

Often spiral stairs have a near full circle handrail on the upper floor, with a gap where you step onto the top landing on the spiral.

How would the trapdoor work around the handrail?

[Theo Markettos]

I'm not sure I quite follow you... this circle is to prevent people falling down the stairs which aren't enclosed?

Do you mean the door is likely to obstruct the handrail when open? I suppose something could be fitted to the bottom of the door to function as a handrail when the door is open, assuming it didn't conflict with anything in the closed position. The door might have to lock open so that it's strong enough to support someone pulling on this rail.

You raise a good question though... how big does the door need to be to get enough headroom when ascending? That could make things tricky.

Theo

[Frank Erskine]

Any sort of a door near the bottom of a staircase could spell a real disaster (cf Victoria Hall 1883). Seriously.

[Cicero]

=============================== Since you're open to the idea of using ropes and pulleys it might be easier to have a detached trap door something like a manhole cover. Such a trap door would only need a single centrally placed hook / rope to lift it vertically and so would not interfere with a surrounding handrail. It could be operated by an off-the-shelf electric hoist. Look here for hoists:

similar arrangement is sometimes used (I think) on blast furnaces but you may not need a 6" thick steel plate for your trap door.

Cic.

[dom]

Would this spiral staircase be the sole means of escape from an upper floor?

[Bill]

In message , Theo Markettos writes

How about a sliding door? As it is a new build could you design in something to slide across the gap from under the upstairs floor?

[Jason]

I staying in a B&B last year that had something similar. Instead of a spiral staircase, the stairs were straight, but they hinged at the top end. When up, the underside of the staircase formed the part of the trapdoor you could see from the ceiling below. When down, there was an entire staircase.

The family slept upstairs during the summer when guests were around, but during the off-season months, the staircase was left up, with half the house effectively sealed off until it was needed.

I know that is not exactly what you are looking for, but if this kind of system is common enough, it may be worthwhile looking into, in case it gives you any ideas.

-- JJ

[Lobster]

As more than one other poster has hinted, there are big implications for building regs here.... what are the "various reasons" the floors need to be separated - can you give more information about the project as a whole? What accomodation is on these two floors, what access arrangements and means of escapes etc are there, etc etc?

David

[Cicero]

================================ It's probably a cannabis factory. They're very fashionable at the moment. Or more mundanely, a stellar observatory.

Cic.

[Jeff]

The company I work for design, supplies and fits custom spirals and I've never heard of anyone doing something like this. In a new build I can see you having major troubles with BC getting it approved. If you waited until you had your completion cert etc and then installed it I suppose no-one would be the wiser but can't see you getting it through on a new build.

I personally hink it's an avoidable accident waiting to happen. Apart from the risk of your mechanism failing and the door braining the operator, you have the risk of trapping some poor sod up there in the event of a fire (other exit or no). It is different to having a door in that at least a door might be broken down or easily swung open, a heavy trapdoor which might have debris fallen on it is another matter entirely. Please think again.

[Owain]

I agree.

I wonder if curved door(s) sliding round the circumference of the spiral staircase would be an alternative. However, I think Building Regs would still require a landing area at the top/bottom of the stairs, for operating the door.

Some new trains have a rather nifty powered curved door on the toilet compartments.

Owain

[Theo Markettos]

The idea is there are two small 'flats' on top of each other and a basement, each which is capable of being used separately. They have separate external entrances, which would be used in the case of fire. But if a larger space is required it's possible to connect them together to form one unit. As space is tight this means a spiral staircase, so I'm trying to come up with ways that the staircase can be opened or closed off depending on need. Such a closure isn't going to be used frequently: I'd envisage once a week at the maximum, more like once a month. Betweentimes it'd be either be locked open or locked shut. As the two flats would be occupied by different people, when closed there needs to be soundproofing between them.

An enclosed staircase with doors is an obvious possibility but it feels like a lift shaft or belltower: claustrophobic. It also doesn't connect the two living spaces very well when in use. I'm trying to come up with something better.

As regards building regs go... it's in Greece so UK regs technically don't apply. However anything that's a silly idea here is probably a silly idea there so it'd be sensible to pay attention to them. (And I get annoyed with how slack their regs are, so Doing Things Properly is definitely an objective).

You're right, though, that careful thought is required regarding the safety implications... even if something is intended not to be used in emergency it quite possibly will be.

Theo

[Theo Markettos]

Those are good points... am thinking a bit more :)

That's an interesting idea. A landing area isn't a problem. From what I hear the train doors have difficulty with maintenance, given the beating they take from passengers. However a flat sliding door, or a pair of double-leaf doors might work...

Thanks Theo

[dom]

Have you considered an "alternating tread stair" :

are very compact and can be made by any decent joiner - and perhaps more suited to a trap door.

[Owain]

More crucially, there would have to be fire compartment separation.

Glass, glass brick or glazed walls, and even glass stair treads, can be constructed to meet UK building regs.

Owain

[dom]

A "yacht hatch" type design might be suitable:

use an overhead sliding hatch and and a smaller lift-out vertical section.

The advantage is that the hatchway stands a foot or two above the floor (deck) it opens onto, so less danger than of a gaping hole - and it provides containment for the top of the handrails - without interfering with the operation of the hatch.

[JohnW]

Since you are looking for compact solutions, I've seen these sold and used in France, with a closing floor hatch:

[Clint Sharp]

In message , Theo Markettos writes

Think Bond, sharpen the edges of the staircase, attach multi-horsepower motor to the top and turn on, staircase augers down into ground opening up a very attractive 'rustic' well, the addition of a few strategically placed sharks with lasers and you've achieved not only your objective of separating the floors, you've also got a nice focal point.

All silliness aside, I *have* seen this sort of thing before with the trapdoor, I'm sure you'd find similar arrangements in old Windmills and lighthouses but I think you'd have to build some sort of separate guard around the top to stop people falling into your shark filled pit^H^H^H^H^H^H down the stairs. If it's only moved every now and then, what's up with a removable floor section that can be stored somewhere?

[Ren]

replying to Clint Sharp, Ren wrote: I also have this problem but it is an old house. It has the spiral staircase leading from the kitchen to the basement. Code required we move the oil furnace to a spot in the basement , so now all you hear is the oil furnace. I was thinking about a trap door to cover the stairs for the purpose of keeping some of the furnace noise out.