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--- layout: post title:What headroom do you require over a loft stair. path:What headroom do you require over a loft stair. categories: section: post ---
The Building Regulations require that you maintain a clear headroom of 2000mm on any access between levels, which includes staircases. That includes loft staircases, spiral stairs in fact any staircase. Headroom has to be maintained while ascending the stair and also on the landings at the top and bottom. People are always telling me that on a loft staircase you can reduce it to 1900mm but I disagree. If you look at what part K 1.10 of the English and Welsh Regulations actually says, you will see a nice diagram that really defines it quite clearly. It basically says that in a loft conversion where there is not enough space to achieve the 2000mm headroom you can reduce it to 1900mm in the centre of the width of the tread. But the diagram shows a sloping ceiling which has a minimum of 1800mm at one side of the stair and 1900mm in the middle, by implication you would then have 2000mm on the other side of the stair.
This relaxation of the normal 2000mm headroom therefore only applies to a sloping ceiling in a loft conversion,which is over the staircase. It does not allow you to reduce the headroom to 1900mm over the whole width of the stair, it has to be a minimum of 1800mm at one side and 1900mm in the middle.
The Loft Staircase Doctor
--- layout: post title: What does a Genius spiral stair fix to at the top. path: What does a Genius spiral stair fix to at the top. categories: section: post ---
I am amazed at how many times I get asked this question, I suppose it is not that obvious, a lot of people assume that the centre pole will go right up to the landing ceiling and fixed to the rafters above. The reality is that a spiral staircase like any other stair normally ends at floor level and all that projects above the floor is the balustrading, which is there to stop you falling back down the hole.
With Genius spiral staircases and in fact all other kit spiral staircases that I can think of there are really only two main fixing points to the structure of the building. The first is a circular base plate on the bottom of the centre pole that is bolted to the floor. Then the top of the pole is secured to the vertical face of the ceiling aperture via the top tread that normally being a landing triangle. The landing triangle is bolted to the centre pole at one point of the triangle, the the opposite side of the triangle is butted up to the edge of the floor and secured with angle brackets underneath to the timber trimming or trimmer joists surrounding the opening. If it is a concrete floor slab or even a wall you would use the same brackets but different fixings.
The two fixing positions described above are all that is needed to hold the centre pole rigid. All the treads are simply attached to the centre pole. If the spiral staircase has any walls surrounding it is also advisable to attach brackets between the wall and any tread that passes it. These are not a necessity but they do help prevent any slight lateral swaying movement that is always likely to occur on spiral stairs.
The Spiral Staircase Doctor
--- layout: post title:Do kit staircases need any adjustment after installation. path: Do kit staircases need any adjustment after installation. categories: section: post ---
Theoretically once installed modular kit spiral and flights stairs do not need any real maintenance or adjustment. However it is my belief that most will need a re-tightening of nuts and screws at some point in the first year of its life. The reason for this lies in the moisture content of the timber components. Timber is hygroscopic, it tends to absorb or lose moisture due to the temperature and humidity of its environment. Unfortunately it will also tend to change in shape if you add or reduce its moisture content. Joinery manufacturers have long been aware of this and will attempt only to fabricate with timbers of a known moisture content. Joining two pieces of wood together with different moisture contents will cause problems when they eventually stabilize in their permanent environment.
Reputable modular kit stair manufacturers will make sure that their timber elements leave the manufacturing plant at a nice stable moisture content of around 10%. The problems start when the staircase reaches site. If it is a new build the environment it will almost be certainly be unheated and damp due to the tonnes of water used in brick,plaster and concrete construction. So the timber elements of the stair will increase in moisture content and size. Once the building dries out the timber elements will lose moisture content and shrink a little. This will cause any screwed or bolted joints in the stair kit to ease a little and create a bit of unwanted movement in the stair structure. The solution is is tighten up the fixings.
Ah but what about the nice stable environment of an existing property I hear you say. True there will be less of a problem apart from when you have to turn up the heating in winter. This has the potential to loosen joints the same as a new build property. In my experience it is a good idea to consider re-tightening all fixing after the first heating season, this will pay dividends and will probably only need doing in the first year.
The Staircase Doctor
The answer is yes you can, but with great care. In an ideal world you would have made provision for the Klan spiral staircase baseplate at the installation stage of the underfloor heating. By that I mean that you would have left an area at the centre point of the stair approx 500mm x 500mm with no heating pipes or electrical cables in it. However it is not a perfect world so a different approach is needed if the floor is already complete..
There are two basic problems to overcome if you are trying to fit a spiral staircase over an existing solid floor with underfloor heating in it. First you must not at all costs drill a fixing hole into a water pipe or electricity cable. Secondly you have to make sure that the baseplate of the spiral staircase is not sitting on anything compressible which will cause the stair to move. Bear in mind that the 200mm diameter base plate of your 200 kgs. Klan spiral stair has to take not only its self load but also your 150kgs granny as she wanders drunkenly up the new spiral staircase. Modern construction requires an insulation layer somewhere in the floor construction, this normally will have something like a 75mm concrete screed over it; this being adequate to take all normal loads without compression. However a point load like a spiral stair may need considering.
Solutions to both of these problems is really a matter of common sense. First you need to know the details of the floor construction so that you are aware just how just how deep you can drill, and the amount of compression that is likely. If there is no floor finish on top of the screed I personally would consider carefully breaking up the screed around the area of the base plate and shoving any pipes or cables out of the way if possible or at least marking their position if not. I would also remove any under screed insulation for a small area directly under that baseplate. The floor would then be re-screeded including the area of removed insulation. Once this has cured you can mark the runs of pipes or cables on it, so that you know where you can drill. Assuming that this is not on, then alternately you will need to replace any supplied expansion bolts with shorter alternatives that you can be sure will not penetrate the screed. This will of course not help the compression of insulation problem, which may not be a problem anyway. Should you decide it is, then your options are limited to digging it out as above or spreading the load over a greater area by forming some form of plinth under the spiral stair. Bearing in mind that this will affect the overall height of the Klan spiral stair. A customer once suggested that rather than sit the stair on his wood block flooring he would sit the base plate down on the screed and carefully cut the wood block around it. This would prevent any lateral movement of the baseplate without any further fixing needed. I am not sure I could totally recommend this action but preventing lateral movement is for sure half the battle of fixing the baseplate.
In conclusion do not be put off, a Klan spiral staircase will look good and function well, and in my time I come across a great many spiral stairs that have been fitted on top of underfloor heating systems without any problems.
The Spiral Staircase Doctor
The luxury Berlin space saver stair is by a mile the nicest looking alternate tread space saving staircase on the market. Unfortunately the wrap around stainless steel balustrade system can have problems meeting the Building Regulations. It is not alone in this, most wrap around wire or rod balustrade systems struggle to meet the 100mm sphere rule and can be considered too easy for children to climb. This is a pity because the wrap a round systems on staircases such as space savers or spirals look good and are very much in vogue.
You must also bear in mind that no alternate tread space saving staircase automatically complies with the Regulations, it all depends on what they are used for. In England Wales Northern Ireland and the Republic you can basically use them to serve one bedroom and an associated bathroom, although there are other conditions as well. In Scotland you can not use them at all, sorry.
Another point with the Berlin space saver stair is that the superb curved treads which give far better access for the feet than other paddle shaped treads actually fall foul of the Regulations because the tread nosing are not parallel. This really is a shame because believe me they are better than anything I have come across in space saver stair treads.
With the use of all space saver stairs I would recommend that you seek advice from your specific Local Authority before you proceed too far. Different Authorities have different opinions on their use.
The space saver stair Doctor
You will find the answer in BS 5395 part 2 but it will not tell you the actual diameter required for a spiral staircase. The standard specifies the clear width required for different applications. For instance spiral staircases serving as the main house staircase would come under category B which requires a clear width of 800mm.
The definition of the clear width is the distance between the outside of the spiral stair centre pole and the inside of the handrail, this in practical terms is the width that you have available to walk up or down the stair. This is a good way of specifying the required size because if you have to escape down it in the event of a fire this width could be critical. Specifying the outside diameter of a spiral staircase does not really define the clear width because different designs and different styles have different sized centre poles and handrails which will in turn have change the amount of clear width.
None of the above really helps the questioner, what he really wants to know is how much area he needs to leave to accommodate a compliant primary spiral staircase in his new house design. The answer is about 2000 mm diameter, I say about because as you now know, without knowing the constructional details of a the specific spiral stair I cannot say for certain. Personally for design purposes I would leave if possible an area 2100mm square this would just about cover most models of spiral staircase that you are likely to buy. In my experience I have not found any modern designs of Category B compliant spiral stairs that are smaller than around 1900mm.
The only real safe way of answering this question is for you to choose your spiral stair model and ask the manufacturer what diameter will comply under BS 5395 part 2 as a main staircase in a dwelling.
The spiral staircase Doctor.
It is difficult to generalise on all manufacturers of kit spiral staircases, although what can be said is that they are all continental and almost all do their own load testing etc. aimed at their own national standards but not specifically for the British Standard. The chances are that there will be something within the British Standard that will not be covered in the Continental equivalent and visa versa. That is not to say that either is wrong just different. Theoretically all us EU communities are attempting to eventually bat on the same wicket, but in the current state of the union that looks less like a priority.
So the questioner has his eye on a nice kit staircase and he knows that if someone claims that it complies with the British Standard then it will be acceptable under the Building Regulations. That is perfectly true but a very difficult claim to make with any adjustable spiral stair kit. The ability to adjust means that the end user can in all probability adjust say the tread rise outside of the British Standard maximum therefore it would not meet the standard. So, why not make the adjustments so that they can only remain within the standards. Yes a good solution, but whose standards, the Italians or the Brits! When you make a kit product to sell on the world markets it has to have built in compromises in an attempt to keep everybody happy as much as possible. If you were to go to a reputable bespoke spiral staircase manufacturer you should be able have a staircase made that will meet all the nuances of the British Standard but you will of course pay for the privilege. Reputable kit spiral stair companies should also be able to advise you on which spiral staircases you can use and how you can use them for specific project to meet the main conditions of the British Standard. It would however be a reckless company who boldly stated that it totally complies with everything in the British Standard, unless the manufacturer has had it independently tested and approved by a qualified body. The heavy costs of this procedure means that no continental manufacturer is ever likely to go through this process just for their British market. The only kit spiral stairs that I know of that have been specifically tested to BS 5395 part 2 are the Klan and Civik ranges. The report runs to 50 pages and even then they can only approve the specific sample submitted which means one specific diameter and one specific floor-to-floor height. The document does however lend credence to a Local Authority approving these particular spiral stair models providing that you check that your specific height and diameter can meet the requirements.
None of the above proves that any other make or model of spiral staircase is not suitable under the conditions of the British Standard, it is just difficult to prove it. As I understand it equivalent European standards should be acceptable in the UK but getting a document from the continental manufacturer that is in a language that is understandable and acceptable to your Building Control department may prove to be another matter.
As always I recommend that you talk to someone 'who knows' who can advise you on your specific project before you go too far. Judging by the number of kit spiral staircases that get approved each year by various Authorities all over the UK you may have less trouble than you think.
The spiral staircase Doctor.
A highly technical question from a deep thinking gentleman.
This gentleman has spotted what the mathematicians amongst can see is a flaw in the geometry of making a helical wooden handrail for variable height kit spiral staircases out of short wooden sections. This is exactly what happens on spiral stairs kits such as the up market Genius range. However the manufacturer is on the case and has an answer for this problem.
Let me first explain the problem. A spiral staircase handrail forms a helix just like the spring on your pogo stick. To form this out of real wood is an expensive process requiring curves in two directions. It goes round in a circle on plan, the circle being the same diameter as the spiral stair. It also has to climb from the bottom to the top stair tread which is the second curve. OK all of this is possible but the helix will vary with every diameter and with every height. Therefore you have to make purpose designed helix for every stair. All kit spiral stairs like the Genius range require you to be able to change the height of spiral stair. Without this variability you would no longer have off the shelf kits, but would have to pay a lot more for a spiral staircase made specifically for your floor-to-floor height and diameter.
There is a further problem with kit spiral stair helical handrails, they are not only difficult and expensive to make, they are also big, awkward and very expensive to transport in one piece. So having made a helical spiral stair handrail the manufacturer cuts it into shorter lengths so that it can be packed in crate and transported. This process also requires the design of a method of rejoining the pieces together.
So the problem is how to make spiral staircase handrails that go round in a circle of a certain diameter but also curve in another direction to allow for various heights. The first curve is easy you just make a set handrails to suit the various diameters that you supply the stairs in, lets say four diameters. So each diameter spiral stair has its own handrail. The second curve is much more difficult. The only real solution is to also make a handrail not only for each diameter but for each millimetre of height of the stair height range. This is practically impossible as it would require the manufacture of thousands of variables. Failure to do this however means that the handrails will climb the spiral stair at a different angle of pitch to the stair treads, so it will get higher or lower in relation to the treads.
So the solution to this problem lies in the way that the handrail sections are joined. Instead of making the join between two handrail sections butt up hard against each other which would fix the angle of the second curve, the clever manufacturer supplies a clear tapered washer that fits between the two sections. By rotating the washer you can vary the angle of pitch a little on each join. This solves the problem, it is not a perfect solution but it works, and if you take your time with the washer adjustment you will achieve as near a perfect result as makes no difference. Unfortunately it does require you to align it by eye and tape measure as it would be nigh on impossible to produce any kind of tables that would help with this. Trust me it does work, I have seen Genius spiral stair handrails that have been assembled by people who were totally oblivious to the function of the tapered washer and just inserted them any which way. The result looked fine even to my highly critical eye. So worry ye not my mathematical friend the circle can be squared, or near enough anyway.
The Spiral Staircase Doctor
This is a Doctor Who Tardis problem, how to get a quart into a pint pot. There are many types of Victorian terraces but the one I am regularly asked about consists of front and back rooms with two bedrooms above and possibly a single storey scullery extension out the back.The staircase goes across the width of the building between the front and back rooms, access to the back sitting room being under the stair landing. In my opinion this design shows just how good the old folk were at getting the best out of a small space. Fortunately they were not hampered by the modern requirement for unnecessary things like bathrooms or kitchens with dishwashers and microwaves.
So a great design for your great grandparents but a nightmare for access to that nice big unused loft space. Unfortunately I have never found a simple answer in providing a loft staircase to this type of property. If there was a simple answer it would have long ago been fashionable and would almost certainly have been adopted by the original Victorian designer. I am always amazed at the number of young people who come to me with the revolutionary idea that they have discovered of buying in a two bedroom terrace and simply making it a three bedroom by using the loft space. Believe me if it were that simple the whole street would already have three bedrooms.
The basic problem is that a loft staircase will require floorspace on the first floor and the only floorspace usually available is found by reducing one of the already small bedrooms. What about putting one stair over the other I hear you cry. That is a good solution but unfortunately access to the loft stair will still require a corridor making in one of the bedrooms to access the foot of the loft stair, so there is nothing to be gained in floor area.
So there is no easy solution and somewhere along the line it is going to cost you space in the existing bedrooms. You may be able to reduce that space by using a space saver stair like the Karina but it will still take up some space and will of course require approval by the Local Authority. A fairly common but expensive solution is to rip the entire room layout apart and end up with a through lounge and a new stair running front to back. You may also be able to convert that stair to a two storey spiral staircase to get access to your new loft room as well. However been warned that You will probably find that the diameter of spiral staircase required by the Regulation people may make this option too large to be workable in the narrow width of your terrace.
I am sorry that I cannot come up with a magic answer, believe me if I could I would be a very rich and happy old man.
The Staircase Doctor