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February 21, 2011

Will my floor take the weight of a spiral staircase.

Not really a question that the old Staircase Doctor is qualified to answer. There is not enough information supplied, in any case all house structures are different so the only way to be sure is to seek local professional advice from a structural engineer

The only thing I can offer is what I know from my own experiences of spiral staircases. Take this as you will, but do not rely on any of it being definitive for your specific project.

First bear in mind that the chances are that whatever spiral staircase you use it is likely that all of its own weight plus any people carrying say a piano will be carried by a base plate on the centre pole that is probably no more than 200mm in diameter. Therefore the questioner is being quite sensible to raise the query before they go to far into their spiral stair project.

In reality you are only likely to carry your grand piano up a large main house staircase, so if your spiral stair is to be your primary house stair then I would take the loading factor quite seriously into your project calculations.

More common is smaller secondary spiral staircase going up to a mezzanine or a single bedroom loft conversion. I personally know of hundreds of these that have been put into all sorts of houses with all sorts of floor constructions without a single thought to floor loading. I have yet to hear of one ending up on the floor below, but that does not mean that it cannot happen.

The best scenario is if the starting floor is a ground floor with a solid concrete slab there is very little likelihood of the spiral staircase baseplate punching a hole through this type of floor, but be wary of putting fixing bolts through underfloor heating. Also be wary of any compressible floor insulation, a solid area without insulation is to be recommended under the spiral stair baseplate.

Suspended timber ground floors are also less problematic as it is usually possible to prop this type of floor so that the joists under the spiral staircase are supported down to the oversite concrete. In practice I have probably recommended this solution to hundreds of customers but have never actually had any feedback that any of them have very gone to that much trouble.

Upper floors which in the UK are usually constructed of timber joisting probably pose a bigger risk. Sods law dictates the the centre point of your spiral staircase will fall between two joists and so the whole stair will sit on just the floorboards. At the very least I would personally put stub joists (noggins) between and at right angles to the existing joists under the base plate area. This will at least spread the load over two joists. You cannot however generalise There are different thickness's of joists and different spans not to mention different weights of spiral stairs, so the fail save is always to seek professional advice. Also be wary of modern chipboard flooring which in my opinion is more likely to have a spiral stair base plate punch a hole through it than traditional timber boarding

The same also applies to solid concrete suspended floors, these will have been designed in the UK to take a safe load but the chances are that a structural engineer could probably prove that the calculations show that a typical spiral staircase would require the load to be spread over a greater area than a typical spiral staircase baseplate.

Though it is way beyond the old Staircase Doctors field I am told that modern flats require sound insulation levels between floors that may require a damping effect under the baseplate to prevent transmitted noise from say horses walking up your spiral staircase. For this you need specialist advice both for the spiral staircase and about the rights and wrongs of keeping horses in your penthouse apartment.

The home on the range Spiral Staircase Doctor.

February 16, 2011

Can I get a spiral staircase without a centre pole for my circular tower access.

Yes you can but this is normally called a helical staircase rather than a spiral staircase.

A spiral staircase has a structural centre pole down the middle that holds up all of the treads. This style of stair usually only has a handrail on the outside although occasionally you will find a handrail also wrapped around the centre pole as well. Technically speaking a spiral staircase is also a helical staircase in that it forms a helix around the centre pole, but to make life easier to call it a spiral so lets not go there.

A helical staircase normally has no centre support and turns around a central hole i.e. it forms a helix. Structurally this is a very different animal altogether because removing the centre support requires something else to support the structure. This is normally done with helical strings (side supports) that go the full height of the staircase, usually both on the inside and outside edges of the helix. As you can imagine this is serious engineering and therefore a serious hole your pocket as well.

I suspect that the questioner is is talking about a large diameter tower (lucky lad) that requires a helical staircase around the outside wall. A smaller council house type tower would simply have a spiral staircase plonked in the middle. It is possible to form this type of staircase in several ways including using the circular wall as a structural support. Whatever type of stair is chosen it will need to be designed and installed by a specialist company who know what they are doing. This will include making sure that the elements of the stair can actually be physically got into the tower prior to assembly. It could look superb but needs careful design and a lot of money.

It all sounds very expensive but very nice, as a staircase enthusiast I cannot imagine anything nicer than an evening in my tower sipping brandy while admiring my open plan minimalist helical staircase to heaven (with apologies to Led Zeppelin).

The Heavy Metal Staircase Doctor

February 07, 2011

Do you recommend the Klan spiral staircase kit.

The simple answer is yes I do, I believe that the Klan spiral staircase ticks more boxes than any other budget kit spiral stair on the market. For a start it has been around longer than any of the rivals and is for sure the world brand leader in the kit spiral staircase market. These two facts are important, the longevity of the Klan and the vast numbers sold are proof that it works and that by now it is tried and tested with any design faults ironed out long ago. The Klan spiral stair is also excellent value for money, though not the cheapest on the market it still heads the leader board because of its manufacturing quality.

I think it is worth taking a look at the history of the kit spiral staircase market to show why I still recommend the Klan. In the early days when kit staircases were still a novel concept the Klan had no real rivals so sold in increasing numbers without a problem. As the market developed more and more manufacturers got in on the act and produced alternative spiral stair kits based on the Klan theme. The excellent design of the Klan left very little room for producing alternatives that could improve on the original. This left only price as a way of grabbing some of the market. These days attempting to produce ever cheaper prices is the norm in this web driven society. In my opinion this had led to kit spiral staircase manufacturers producing stairs with ever cheaper parts in an attempt to beat the opposition on price. Even the manufacturer of the all conquering Klan spiral stair range has now produced a cheaper alternative to get in on the act. The Devil is however is in the detail, you only have to look at the handrail and the fixing details to see why it is sold for less money.

Personally I have always thought that what you get in a kit spiral staircase offers outstanding value for money when compared to the alternative of having a spiral stair made-to-measure for you. Considering that you are probably going to look at and walk up your spiral staircase everyday, I think there becomes a point where the little extra expenditure on quality and reliability is worth every penny. For me anyone looking for a small diameter spiral stair in the budget price ranges need look no further than the Klan.

The Staircase Doctor

February 02, 2011

Where can I get an external spiral staircase in a coloured finish.

Before I answer this question we all need to remind ourselves that in the contest between painted surfaces and the world's climate, The climate wins every time. We may be able to put a man on the moon but old mother nature rules us with a rod of iron

The result of this uneven contest between man and planet is that when it comes to protecting external metalwork including spiral staircases there are not many options that work satisfactorily. The tried and tested method is galvanising a catch all name for a plating process usually using zinc. This works and depending on how well it is done will give a long lasting surface, although even it will not last forever. The down side is that weathered finish is the ubiquitous dull grey colour that we see everywhere.

From an external spiral staircase manufacturers point of view a galvanised finish offers the best and probably the cheapest solution to a reasonably weatherproof product. To offer an alternative external paint type finish is likely to be more expensive and less reliable. Sure there are new space age products around now a days, but they are expensive and in my experience still not as good as zinc plating. If we are talking about kit external spiral stair manufacturers then from my knowledge they all agree with me with one exception that uses a cathaphoresis painting process. I will not go into this details of this process which I think is used successfully in the Automotive industry, but the only external spiral staircase that I have been involved using this process lasted less than six months before the internal rust signs became visible.

So you want a external spiral staircase in a colour to match your geraniums, what can I suggest. Personally I would accept that galvanised is best and purchase a standard kit galvanised external spiral staircase from a reputable supplier.The cost saving over a made-to-measure will probably pay for your colour finish. I would then have it painted to the colour I wanted. I would accept that whatever I do it will need re-coating at some time in the future, but hey. it gives you an opportunity to swop from geraniums to daffodils.

A word of warning, the painting of galvanised metal requires a different approach to other surfaces. Many paints will not adhere to the galvanised surface and processes such as etching the surface first are required. It is rocket science so check what you are doing before you proceed, ask the Painted Galvanised Metal Doctor not me.

The Staircase Doctor