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July 28, 2010

What are the rules about maintaining 2000mm head clearance height on a staircase?

A good question and really quite simple to explain

The answer lies in Part K of the UK Building Regulations which actually applies to England and Wales , Scotland and Northern Ireland have there own similar rules, bless them. This regulation says that you must maintain a clear headroom of at least 2000mm on both a stair and the landing areas at the top and bottom of the stairway. On the stair this is measured vertically from an imaginary line (pitch line) that passes through nosings of each tread. There is a relaxation for loft conversions where there is not enough space to achieve this under a sloping roof. In this circumstance you are allowed to have 1900mm headroom in the middle of the tread reducing down to 1800mm on one side that would mean it being higher than 1900mm on the other side. You cannot have it 1900mm all the way across.

You may ask why they have this rule, the answer being all about safe access and particularly egress in the case of a fire. I do not think it is a silly rule, but try applying it in a cottage where the ceilings are less than 2000mm high never mind the stairways. One has to hope for common sense on the part of Big Brothers inspector when it comes to older properties. In general I have found that common sense does prevail in such cases, but you are on your own if you are trying to squeeze a room out of a loft space when it is clearly not high enough to house an Itura forest pygmy.

Time and time again I have been asked to work out how to squeeze a regulation compliant stair into a loft space where the only place that you can stand up in is under the ridgeline. It is OK if you are prepared to extend with dormers coming out of the roof, but many times people do not want to go to the expense or trouble of a full conversion, but just want to utilise the existing loft area for storage. This is usually a euphemism for I am broke have four kids and only three bedrooms.

I do not blame people for using what space they have available in their own little castle, but I add note of caution, house fires kill and in the admitted unlikely event of a fire, getting people out in a hurry can save lives and should be considered when you are extending your nest.

So we now know the rules and you are tight for space is there anything you can do? Unfortunately there is no magic potion for this problem unless you live in a tardis. There are however a few things that you can consider.

OK you cannot afford Dormers style windows to create space, but a Velux type roof window strategically placed over the stair can very often create the extra few millimetres of required headroom, plus it lets in light and ventilation

A spiral stair under the ridge line may work when a longer flight will not. See earlier blogs on the Regulations for spiral stairs.

A space saver stair is steeper and takes up less room so by the nature of the beast is likely to work where a longer wider full staircase will not. See earlier blogs on the Regulations for space saver staircases.

A final note of caution, if you are thinking of putting a stair over a existing staircase remember that you will also need to maintain head height on the existing stair as well. A lot of people cannot see how this can be a problem but believe me your new upper stair can easily encroach on the existing, so it needs thinking about

As always if you do not know ask a man who does

Pharoah stair Doctor

July 21, 2010

I do not know my floor-to floor height, can I still order a spiral staircase?

This question can often arise if your project is new build. You quite rightly want to organise the spiral staircase well in advance but yours floors are not yet constructed.

Logically you can take the floor-to floor height from your architects drawings but this would be a folly, take it from an old construction hand there has never been a building constructed that is an exact match to the design. "What about the great pyramid at Giza I hear you cry". Well I have sat on top of it and can assure you that like most things it was more cock up than design, they have not even finished it yet! Khufu is still in dispute with the contractors over the workmanship. The best excuse I have ever heard in the site cabin was from the foreman on the Taj Mahal who when it was nearly finished had it pointed out to him by the Shah Jahan that the external minarets were not vertical but actually leaning slightly away from the main structure. "Yes" he replied without a hint of surprise, "I have done it that way so that if there is an earthquake they will fall away from the building"! What a star, that man is my hero, he even got a bonus from the boss for his forward thinking.

So what can we do; as you realise the height of a spiral stair is critical, you need the top step to finish at the same height as the upper floor. In fact this applies to all stairs not just spiral staircases. So lets look more closely at the problem.

Usually you can get fairly close to know the finished floor-to-floor height, the unknowns are often the thicknesses of the as yet undecided floor finishes and probably the un-laid screed. Well if the floor finishes are the same on both floors they will cancel each other out so you can discount them in the calculation. Floor screeds by the nature of the beast are never perfect despite what Mr "I only accept perfection" will tell you. If your screed is supposed to be 75mm thick it may be a possibility to put a 75mm. thick pad at the centre point of the spiral stair and tell the screeder to use that as benchmark to work away from. You might well already have other benchmarks such as existing floors that you also need to work to and these may differ slightly, but every screeder worth his salt can usually run the difference out without you ever being aware of it.

So we now have our best shot at what we think will be the finished floor-to-floor height, what do we do now.

If you can, use a kit spiral stair, they are all adjustable in height, so adding or removing a height adjustment shim can accommodate any discrepancies.

If your spiral stair is made-to-measure, give it your best shot in floor-to-floor height then consider taking say 5-10 mm off the height of the bottom tread at the manufacturing stage. Get you supplier to supply four 5mm. base plate shims which will allow you to pack up the base plate by up to 20mm if need be. You will also need an extra deep base plate cover so that it will cover the extra shims. Technically this will mean the bottom tread will have a slightly higher or lower tread rise than the other treads which is a no no, but I doubt anyone will ever notice. If they do, say it is part of your earthquake survival strategy, it always works.

A final thought on floor-to-floor heights for any staircase. If your upper floor is being carpeted consider finishing the top tread at the height of the top of the carpet. This will make a better detail without the need of a visible carpet edge gripper.

The Pharaoh Stair Doctor

July 09, 2010

I want to replace my existing my existing ugly spiral staircase, what do you recommend?

a fairly unusual question, but a similar thought has often occurred to me about my other half.

Spiral stairs have always been desirable but never that popular because of the expense and the room layout required to accommodate them. There has always been a small trend to include a spiral staircase in one off architect designed houses, but anything over twenty years old is probably now looking dated. Just like kitchens or bathrooms, what was once desirable becomes ugly as fashion changes. When people come to me to change an existing spiral stair I have a rough idea what the existing looks like. Usually it will be a mock fancy wrought iron antique animal,definitely no longer in vogue, or a crude metal and timber thing from the seventies that never looked good even when it was new.

Whatever the reason the spiral stair has to go, and these days there are wonderful options on the market for spiral staircases made in arrange of styles.

I cannot really offer suggestions as to type of spiral stair, that all depends on personal taste and depth of pocket. However I think the best I can offer are a few pitfalls to avoid before you go too far down the road of replacement.

First in order to replace you have to rip out the old spiral and this may be a bigger job than you imagine. A lot of older spiral stairs tended to be built in, sometimes even fabricated on site with the top step being formed out of the house landing area rather than part of the stair. Most modern spiral staircases have this landing included with the stair as a top tread, so it may mean some serious alteration to your landing floor in order to accommodate a new spiral stair.

When you take out the old spiral staircase will the base plate leave a hole in the floor finish that needs making good? This also applies to the upper floor finish and any other points of contact with the house structure.

Have you thought about landing balustrade? This will need to be replaced to match the new spiral stair, and this again may need lots of remedial work to the upper floor and wall finishes.

Modern spiral stairs tend to have a bigger centre pole than older welded up all metal models. This means that you get less tread width for the same diameter, which in turn may mean that it dose not comply with the Building Regulations if the new spiral stair uses the same diameter as the old. Mind you in all probability your old spiral staircase does not comply either.

The angle of tread rotation of a new spiral stair may not match the old, this will affect the position of the first tread at the bottom, it may no longer be where you want it to be. You can of course get a spiral stair made to match the rotation of the existing, but it will cost more and may not be available in the economic kit spiral stairs that are now available.

Other than the above I cannot think of any reason why you should not go for it, a new spiral stair will enhance your property value and add a real Grand Designs factor.

The Stair Doctor.

July 05, 2010

Are there fitting services available for modular kit straight or spiral staircases?

Yes there are some retailers who offer a fitting service and some who don't mainly because most of these products are sold as a DIY/ local builder installed product with a complete set of fitting instructions and an installation DVD. There are also a few independent fitters around who will travel to fit staircases.

I think you have to be realistic about costs when it comes fitting a kit staircase. Do not fool yourself that it will be a carpenters wages for a day. Offering a nationwide fitting service is an expensive business and attempting to only fit locally is not likely to produce enough work to make it a worthwhile occupation. You also have to consider that in most cases actually fitting your spiral staircase is only half the story. In lots of cases new floor openings have to be formed and old staircases or walls may need moving. These are long and expensive jobs for a travelling stair fitter. If you are not fitting yourself, do you also want the fitter to visit and survey it as well? This is possible, but not done for nothing if he is not local.

It is very difficult to guess peoples prices on such matters but I would expect a straight forward fitting of say a 1600mm diameter Genius spiral stair kit in an opening that is already prepared and waiting to be around £500- £600 at 2010 prices, maybe even more if you have to take travelling time and even overnight accommodation into the equation. More like £2000 plus if there is much extra work to the surrounding structure or stair well to be done. Spiral staircase kits are not so complicated to fit but it would be a brave man and his mate who could guarantee doing one in day every time.

If fitting costs are an issue there is strong argument for using a local tradesman or a local jobbing building company, you may even drop on a local experienced stair fitter but that would be a stroke of luck. Local tradesmen are more likely to be available to visit prior to fitting to assess the situation, and they are certainly in a better position if any unexpected problems arise that need extra material etc. They also have a local home to go to if the game runs into extra time.

You could adopt the attitude that if you are given a fixed price then none of the above problems matter to you. Contractually that is true,but I have lost count of the projects that have ended in tears because of an unrealistic customer, or more likely an unrealistic tradesman, rushing trying to solve unforeseen problems in a fixed time and price frame.

So to sum up, if you want the stair fitted by an existing expert with no hassle what so ever be prepared to pay. If you are prepared to look for a good local carpenter or other tradesman with a brain you may save a lot of money. Who knows after fitting your stair your tradesman may even become the local expert fitter for your neighbours when they try to go one better than your stair project.

The Stair Doctor