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March 30, 2010

Can I have a spiral stair as my main staircase?

The answer is yes you can, providing you have the space on both floors to accommodate a circle of approx 2000mm (6’7”) diameter. That is the sort of size that is needed in order to have a spiral staircase that is acceptable under the Building Regulations as a primary staircase in a domestic dwelling.

The actual diameter will vary depending on the stair construction. The requirement is for an 800mm. clear width, which is the distance between the centre pole and the handrail. So it all depends on the size of the handrail and the centre pole, but in practical terms you can reckon around 2000mm. to get a compliant spiral stair.

2000mm.x 2000mm. is a big area and very few houses have that sort of space available for a stair. This is one of the reasons that you rarely see spiral staircases as a primary house staircase. The situation is different for as secondary staircase serving say a bedroom in the loft. In that case you only need a 600mm clear width, so typically you can use a much smaller diameter of around 1500mm.

So you have the space (lucky you), should you use a spiral stair as your main house staircase? The answer really is all a question of function against style.

I would have to say that normally a flight style staircase wins in terms of ease of use over a spiral stair. It is close call, but the treads coming to point at one end and the helter skelter path of a spiral staircase makes it a little less functional to use. You also have to accept the fact that treads of spiral staircase are all cantilevered off a centre pole and will probably give you a little more movement under foot than a solidly built traditional staircase.

On the other hand when it comes to style even a bog standard spiral staircase adds a wow factor that is difficult to achieve with even a luxury traditional staircase.

So you pays your money and you takes your choice. From my experience here in staircase land it is the wife who chooses, so that will be the spiral staircase then!

The Stair Doctor

March 18, 2010

How do you adjust the height and length of a Genius modular kit stair?

In building industry parlance staircase height and length are referred to as the rise and the going.

The rise being the height that you have to step up between one stair tread and another.

The going being the amount of tread front-to-back that you have to stand on.

By making these adjustable you can alter the overall height and length of the entire stair.

Modular kit staircases including the Genius are designed to be adjustable in both rise and going in order to make the same kit suitable for different applications.

The method of adjustment varies depending on the manufacturer and the model.

The Genius luxury staircase kit is adjustable in height by having clear dense PVC shims that go between each metal tread support element. The number of shims varying depending on what your overall height is. You do not have to work this out for yourself; the fitting instructions include a table that tells you the number of shims required for every stair height within the kit range.

The cheaper version of the Genius staircase is called the Kompact stair. This model adjusts in a different way. The metal support element under each tread consists of a tube that is held in a clamp ring attached to the tread above. By sliding the tube up or down in the clamp ring you can adjust the height to suit before tightening the clamp.

This method has the advantage that it is infinitely adjustable within the limits of its range, where as the Genius system is only adjustable to accuracy of the thickness of a shim which is 5mm.

Most kit stair systems use one or the other of the above methods, and both make the kit capable of fitting a range of applications and allow for minor adjustments. The ability to adjust height or going is a major advantage over made-to-measure staircase that will be scrap if your order dimensions prove to have an error in them.

The adjustment of the going (horizontal adjustment) on modular flight stairs is possible because the holes for the nuts and bolts that clamp each metal tread support to the next one are slotted, thus allowing for horizontal adjustment before you tighten them up.

Kit spiral stairs such as the Genius T spiral stair or the Klan spiral staircase are also adjustable in rise but not going. With one or two exceptions all kit spiral stairs adjust height by means of the shim method. In practice this shim becomes a washer that goes between the staircase tread and the centre pole sleeve. As before the more washers that you insert the higher the tread rise will be. Also as before you do not have to calculate this, just read off the number of washers needed for you height from the table supplied.

A word of warning! For safety reasons the Building Regulations specify sizes for staircase rise and goings so be aware that just because you can adjust a kit staircase to a particular height and length is does not automatically mean it will comply with the Regulations. This requires a calculation that is balancing act between rise going and pitch, for this you need a man that knows like the poor old staircase doctor.

The Staircase Doctor

March 08, 2010

Are there different staircase regulations for different parts of the UK ?

The answer is yes, and if you add the Republic of Ireland the answer is yes again, although it has to be said there is a common theme.

The following will tell who has the power of building life or death over you.

  • England and Wales together (God bless them for using common sense)
  • Scotland on its own (all the fault of devolution over common sense)
  • Northern Ireland on its own (ditto)
  • Republic of Ireland on its own (who can blame them)

You would think that as E U are trying to get us all together under a common set of rules, that a couple of little islands off the coast of the mainland could at least get there act together for the good of building kind, but not a bit of it. ‘We have our own nice new parliament so we will have our own building rules, thank you very much’

When you see just how far apart these small islands that speak the same language are, it does not bode well for the European Union, not to mention the ‘mankind to save the planet brigade’.

OK already, I will get off my frustrated high horse and stick to the point.

So we now know who is in charge of our own little castle (and what I think of it) but what difference does it make?

Well as regards staircases it is confusing because all the rules seem to based on the English/Welsh regulations, but with a few little awkward differences that seem to be added just to say “we have not copied sir honestly”.

For instance the requirement of the amount of tread that you have to stand on (going) on a domestic stair is

  • England & Wales, minimum 220mm (I cannot imagine who came up with this)
  • Scotland, minimum 225mm (either a sad joke or a mistake surely)
  • N.I., minimum 220mm
  • Ireland, minimum 220mm but optimum 250mm (what are you on about?)

Now this difference may seem like nothing, but most kit stair manufacturers based their designs on a compromise to try to keep everybody happy in Europe, and as lots of places have far less of a going requirement they chose 220mm as their maximum. This was all fine and dandy until the Scottish law makers rocked the boat and added an extra 5mm. This at a stroke excluded their population from using the basic (best thing since sliced bread) kit stairs that everybody else uses.

The Irish having introduced an optimum 250mm means that no building inspector would look happily at a measly 220mm again, although in my experience the farther West that you get the less this applies.

OK I have insulted just about everybody now but you get my point. Trying to design and work with staircases that have to have different geometry for different locations is an unnecessary nightmare.

The following is one example of that amuses me in the rules governing spiral staircases.

By the nature of the beast spiral stairs have great difficulty following the geometry of straight staircases.

You cannot for instance have a going of 220mm on a 1500mm diameter spiral staircase without causing head clearance problems as you ascend the stair. Take my word for it, or read the blogs relating to spiral staircases for an explanation).

The clever people at the British Standards institute realised this and produced a nice clear set of rules covering spiral staircases. The going requirement for a 1500mm spiral stair being a mere 145mm min.

So when the Building Regulation people came to write their rules, thinking about the geometry of spiral stairs made their head hurt, so they all plumped for “if you build it to BS 5395 it will be acceptable to us, end of story”. It is OK having to make rules but you do not want to work to hard thinking about it, “lets just shove an extra 5mm on some where and go and have a drink.”

There are other small differences between the various Regulations governing staircases, these can become important, so do not assume that if it is OK in Scunthorpe it will be OK in Coleraine. Always check with your specific Local Authority

The Staircase Doctor.

(On his way to the asylum the staircase doctor denied all knowledge of writing this epistle, please forgive him poor old chap, it has been a bad day)

March 02, 2010

Space saver stairs and the Building Regulations

In England and Wales Part K of the Building Regulations specifies what you can and cannot do with staircases, in Scotland it is part 4 of the technical handbook, in Ireland it is part K of their Regulations and in Northern Ireland it is part H.

They are all different, and when it comes to space saving stairs I believe that only England & Wales have a separate set of rules covering the use of space saver stairs. I have to be honest and say that I have never been totally sure of who allows what when it comes to space saving stairs, the rules such as they are, can be open to interpretation, and in my experience different Local Authorities have different attitudes to space saver stairs. Over the years I have had discussions with Building Control people all over the shop and the feed-back I have been given is

England and Wales: Space saver stairs are OK as long as the meet part K 1.22-1.24 but a few Authorities will find any reason to object.

Scotland: They will not have them at any price

Ireland: Seem to be more easy going, I do not remember an objection to a sensibly used space saver stair.

Northern Ireland: Generally the same as England and Wales

So that is what I think is the case for all of our small group of islands, but let us face it, if in doubt you have to ask your own specific Local Building Authority, I have never ceased to be amazed at the different responses that I have heard on this subject. To be fair it is probably not the most common or the most important question that the average Building Control inspector will have to give a decision on, so I would expect a variation in response.

OK now that it is as clear as mud as to who allows what, let us now look at what exactly a space saver stair is as defined in Part K of the Welsh/English Regs.

The terms space saver stair or space saving stair are both nice and self-explanatory but strictly speaking the only way to save space over a standard staircase is to make it steeper. The only way to make it steeper and still have enough tread to stand on is to have a special paddle shaped tread which alternate left and right. So the Regulations refer to a space saver staircase as an alternating tread staircase.

The mind set of the Building Regulations as regards stairs is to make rules that make stairs safe to use in a normal situation, and adequate for evacuation in the case of an emergency. From this you can see that alternate tread stairs which are steep and require a bit of thought to walk up and down, are not suitable for evacuation for a large number of people who are in a hurry.

To that end Part K of the Regulations allow the use of space saver stairs in a domestic property providing the are used as follows.

  1. They must only be used in one or more straight flights for a loft conversion and only then when there is not enough space to accommodate a full staircase.
  2. They can give access to one habitable room with an associated ensuite bathroom.
  3. The steps must have parallel nosing
  4. There should be a handrail on both sides
  5. The rise and going and non-slip treads should comply with the rules the same as full staircases.

These points are my brief interpretation of Part K but you can see the drift, and you can also see that they are open to discussion on what is allowed, the following are some of the different and odd views that I come across in my time in the staircase world.

"It says loft conversion so you cannot use it to access your single room cellar"

Thankfully a one off view that was over ruled by a more enlightened boss. Although you have to accept that a cellar with no windows is probably not the best place to have to evacuate from in the case of a house fire.

"The treads have to be parallel so you cannot have a turn at the bottom"

Again rarely enforced, the truth is that a turn at the bottom of a kit space saver is actually very useful and jumpable if you are in a hurry to evacuate. In my opinion two small straight flights with a quarter landing in between will comply, but is no more safer than winding treads.

"A study is not bedroom so you cannot use a space saver stair"

Actually wrong because the Regs say a habitable room, but the point is valid in the case of say, a kitchen (more risk of fire), or a lounge (potential for lots of people at a party)

"You can put a full stair in one of your bedrooms so you cannot use a space saver stair on the landing"

Sheer badness brought on by a falling out over other differences of opinion between inspector and client. A staircase is always an easy target, a bit like telling a policeman at a random vehicle check that he should be out catching criminals. I guarantee he will find a fault with your brand new Merc.

In this age no one should be put off using space saving staircases, in my opinion they are more safe to use than you think, and they provide access in places where you just could not reasonably get a full staircase. I have been involved with hundreds of them and know for a fact that they work without problems. ‘Touch wood’ I have yet to hear of an accident that could be said to have occurred due to the use of a space saving staircase in lieu of a full staircase.

Having been around for a long time I can also say that modern Building Control Departments are far more helpful and user friendly than they ever were in days of yore. In most cases if you ask first, you will get good practical advice and a common sense attitude from you local guy or gal. "It pays to talk"

The staircase doctor