Staircase Problem.

iamlegend2008

Hi, I am just taking the measurements for the staircase in a new dormer house and have found an error on the plans.

The plans show 14 risers (13 treads) on the staircase with a gap of 950mm at the bottom of the stairs to the wall.

In reality, if we used the regulation limits of 250mm treads then there will only be 500mm which is not enough space.

My staircase guy recommends losing 2 treads which will increase the space at the bottom to about 950mm but this will mean that the vertical height will be 217.5mm which is outside the regulation 200mm per step.

There does not seem to be many other options available.

Any advice would be most welcome.

Thanks.

Poor Uncle Tom

Can you post a diagram of the stairs? The bottom landing area, is it possible to make that a quarter landing and turn at right angles for the last two steps down?

How did this error occur? Are they working drawings or are you working from planning drawings? What did the designer have to say?

Jennyr

Hi,

My Husband makes stairs for a living, just asked him quickly. He suggested the use of winder steps at the bottom or else a landing. It's hard to give sound advice I suppose without knowing the layout of the house.

Is that any help?

Poor Uncle Tom

Be careful with winders, the Building Regulations state they shouldn't be used.

muffler

Poor Uncle Tom wrote: »

Be careful with winders, the Building Regulations state they shouldn't be used.

I believe they are allowed but there is a specific detail for them. I got this from the DoE a few years ago but there is a possibility that the regs could have changed although Im not aware of that.

Still, you're better off without them if its possible.

Jennyr

Here is a quote from the building regs re winders:

The varying thread width of a tapered step can
cause people to misjudge distances and lead to
falls. For this reason, the use of tapered steps
should be avoided. If it is necessary to use them
they should preferably be situated at the bottom of

the stairs.

pacman.anto

Hi, the regulation states that the maximum rise on a private stairs is 220mm! The minimum going is 220mm! The maximum pitch of a stairs is 42 degrees! Many stairs that i make have problems like this and there is always a solution! stairs on the plans differ from what will be made the majority of times, mainly because of architects not leaving enough space! Can you post a plan and dimensions and hopefully i could give you a solution!

pacman.anto

yes of course they are allowed to be used! there is a regulation for them and it would be preferred if the set of winders were as near to the bottom of the stairs a possible! i have often made and fitted a stairs with 6 or 7 winder steps!

parka

pacman.anto wrote: »

stairs on the plans differ from what will be made the majority of times, mainly because of architects not leaving enough space!

That's where a section comes in handy

muffler

There's some good info here on winders and stairs in general.

The regs quoted are for the UK but the same applies here in Ireland.

iamlegend2008

Hi

I hope to scan in a copy of the plan this evening. In summary the staircase opening at the top is the dimensions of a door (approx) so the plan was to erect a simple stainless steel staircase consisting of a single beam with 11 steel plates attached to which we would attach oak treads. There was no plan for winders etc.

I dont really have anyone to discuss the planning error with as the plans were originally designed for another couple and the sale of the site fell through. I later purchased the site with this planning permisiion and then a year later the permission was about to lapse and I was told by the council that they would not renew it so I had to start with the house design that was there.

However if the maximum rise is 220mm (and not 200) then I would be within regulation fwith this approach.

Now where is the scanner

Cheers

muffler

Table 1 at the top of page 5 of TGD "K" here will give you both the optimum and maximum rise and goings.

iamlegend2008

Thanks Muffler, the table was very helpful.

After a bit of Excel work, I have found 3 combinations that may suit. In summary, increasing the number of steps decreases the rise height but increases the length of the staircase which means I need to trim the going size.

I have attached an image showing the figures.


From the table below, in order to get an optimal riser height, I need to use 220mm going size (or in order to use the optimal going size of 250mm I end up with a larger riser height).

Based on the above figures, do people think I should go with 12,13 or 14 risers.

Thanks

No6

iamlegend2008 wrote: »

Hi, I am just taking the measurements for the staircase in a new dormer house and have found an error on the plans.

The plans show 14 risers (13 treads) on the staircase with a gap of 950mm at the bottom of the stairs to the wall.

In reality, if we used the regulation limits of 250mm treads then there will only be 500mm which is not enough space.

My staircase guy recommends losing 2 treads which will increase the space at the bottom to about 950mm but this will mean that the vertical height will be 217.5mm which is outside the regulation 200mm per step.

There does not seem to be many other options available.

Any advice would be most welcome.

Thanks.

Hi I am legend as you can see from the regs 217m is within whats allowed for a domestic, it is a bit high alright but combined with a 250mm going may well be ok, what is your finished floor to floor height?, has there been any creep from the original plans ( ie has it got a bit higher!!) I often find people when building add a bit more here and there, thicker precast floors, an extra few inches here and there and as designers we too frequently design to the limit.

mickdw

2610 seems too low for floor to floor height, sounds more like floor to ceiling height.
The upper floor must be 225 - 250mm so that would leave the ground floor ceiling at about 2360mm which is too low.

Also, best thing is to just draw a quick scaled section of the stairs. The rise and going measurements will give you the angle of the rise which needs to be below 42 degrees. It is also worth noting that while you might decide on for example 200 rise with 230 going, the actual size of the thread would be 250+mm due to the nosing on the step.

Mellor

mickdw wrote: »

2610 seems too low for floor to floor height, sounds more like floor to ceiling height.
The upper floor must be 225 - 250mm so that would leave the ground floor ceiling at about 2360mm which is too low.

I took it to be, floor to ceiling 2400, joist 175, 22mm flooring, 12.5mm (or 10mm w/3skim) plasterboard
2400+175+22+12.5= 2610

It is also worth noting that while you might decide on for example 200 rise with 230 going, the actual size of the thread would be 250+mm due to the nosing on the step.

Why exactly is that worth noting?



OP, Out of the options given, I'd prefer to go with 13 risers@20 and a 230 going

iamlegend2008

Hi

The 2610mm value is the the height from finished ground floor to finished upstairs floor in the dormer.

I have attached a pictured that the stair guy put together explaining the measurements.

Additiionally, I have had to add another going as the stairs will be made of stainless steel and the first going at the top of the landing (which will be level with the landing) will hide the steel beam which will be attached underneath it. This pushes the staircase out to 3000mm which is the absolute limit as is only leaves 800mm from the wall to the 1st tread.

I have seen some requests for a scale drawing but Im not sure what you are looking for. If you let me know exactly what you would like and can try and put one together.

Cheers

Mellor

I'm not being rude. But you need to have a competent person to look at it. You simply don't have the knowledge and are likely to make a mistake. The way you are quantify the goings is wrong for a start. You didn't add another going, it was always there level with the floor, and it should cause the stairs to move.

Without accurate drawings (ground floor plan, first floor plan, section). Nobody here can give accurate advice

muffler

iamlegend2008 wrote: »

I have seen some requests for a scale drawing but Im not sure what you are looking for. If you let me know exactly what you would like and can try and put one together.

Cheers

Mellor wrote: »

Without accurate drawings (ground floor plan, first floor plan, section).

Q & A together in one post

iamlegend2008

Hi

Firstly thank you to all of you for your help. This forum is a godsend.

I realise that I really should have phrased my question better as I dont want a staircase with turns etc. I was really trying to figure out whether to use 12, 13 or 14 goings (since these figures determine the overall horizontal length of my staircase).

I realise that Im not capable of managing this aspect myself which is why I brought in a staircase contractor who provided me with the list of options but in the end, its me who has to make the decision on the number of goings/riser height.

On that basis, I have gone for 12 risers and 12 goings with a 217.5mm riser height and 250mm tread and drawn the whole thing out which I have attached.

The riser height, going depth and 2G+R value are all within regs (just) for a private residence.

I hope the attached picture explains a bit better what I plan to do.

Cheers

muffler

iamlegend2008 wrote: »

On that basis, I have gone for 12 risers and 12 goings with a 217.5mm riser height and 250mm tread and drawn the whole thing out which I have attached.

for the purpose of measuring the horizontal length for the stairwell you would actually have 12 risers and 11 goings (treads). I still think you should reduce the tread to maybe 230 - 235mm which will then allow you to add an additional riser and thus reducing the pitch and riser/step height.

iamlegend2008 wrote: »

The riser height, going depth and 2G+R value are all within regs (just) for a private residence.

Not nick picking here but its actually 2R + G which can give a different reading. I know you got the dimensions right but just pointing out the right methodology.

Overall you are pushing the stairs to the limit and personally Id prefer to see a lower pitch for the sake of children and the elderly if nothing else.

iamlegend2008

Hi Muffler

Here is the alternate version with 13 risers with a riser height of 201mm and a going value of 231mm.

I am keen to make the stairs as family friendsly as possible so does this look better.

Cheers.

muffler

It would certainly be my preference. The pitch is lowered and would not appear to be as daunting for certain age groups as mentioned above.

Mellor

iamlegend2008 wrote: »

Hi Muffler

Here is the alternate version with 13 risers with a riser height of 201mm and a going value of 231mm.

I am keen to make the stairs as family friendsly as possible so does this look better.

Cheers.

I'd go for this option too.

Don't consider the stairs as made of multiple goings and risers. Its one piece, so just make that work.

The length of the going and the nuber of steps doesn't determine the overall length.
The overall length determines the going.
Imo, pitch is most important, then rise, then going

Supertech

With a rise of 217.5 and a tread thickness of 35mm, you don't meet regulations as a 100mm diameter sphere can pass through the open face of the riser. You need to put some sort of downstand on the underside of the treads to make this work.

See 1.1.8 here

http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,1651,en.pdf

Also, your bottom riser needs to be the same dimension as the rest of the stairs to comply ( same document - 1.1.4) At 198mm high there's a 19.5mm difference between the bottom riser and the next. That's too much IMO. Make them all equal - if it's a steel stair structure precise dimensions won't be a problem.

iamlegend2008

Hi Supertech

Thanks for the additional pointer about the 100mm sphere. I will work to incorporate this feature.

I did not understand your point about the 198mm bottom riser. By my reckoning, the height from the finished floor to the top of the first tread is 198mm and the riser height for the rest is only 201mm (3mm different). Have I missed something here ?

Cheers

Supertech

Sorry iamlegend 2008 .... crossed wires (had both pics open and read the wrong one !!)

rok

Sorry to hijack your thread iamlegend2008

Can ye please tell me if the stairs in the pic would comply with regulations?

I have confidence in my Architect but a Precast concrete stairs supplier
questioned if the 2 winders at the bottom of the stairs are compliant.

From reading this thread it seems that it would be but I would prefer a straight flight stairs without the 2 winder steps at the bottom.
I think the Architect designed them that way to make the stairs less steep.

The large X is to denote the double height area over the stairs/hallway. It is a 2 storey house.
The horizontal distance is 3.3m
The floor to ceiling height will be 2.6metres, with 100mm for plasterboard and battens, and then 150mm concrete slab on top
with 75mm screed so overall height from floor to top of finished first floor level would be approx 2.925m ?


I know we have to leave 400mm from the bottom step to the Front door, but I dont have a clue on how risers and goings etc work.

mickdw

Mellor wrote: »

I took it to be, floor to ceiling 2400, joist 175, 22mm flooring, 12.5mm (or 10mm w/3skim) plasterboard
2400+175+22+12.5= 2610


Why exactly is that worth noting?

Ive never used a 175mm joist in a floor. I guess Im just dealing with larger country houses. Would never have the ceiling height down at 2400mm either to be honest. My mistake though in assuming you would have had at least 225mm floor.

In relation to the query of why I thought it was worth noting that for example a stairs with a 200 rise and a 230 going would actual have a stair thread of 250mm due to the nosing, well I was tryng to make the point than sometimes when people work out the going, they look at the measurement and think its too small to stand confortably on whereas in reality, it step will have the extra length. Nothing to do with making the stairs fit etc though just an additional comment

sydthebeat

rok wrote: »

Sorry to hijack your thread iamlegend2008

Can ye please tell me if the stairs in the pic would comply with regulations?

I have confidence in my Architect but a Precast concrete stairs supplier
questioned if the 2 winders at the bottom of the stairs are compliant.

From reading this thread it seems that it would be but I would prefer a straight flight stairs without the 2 winder steps at the bottom.
I think the Architect designed them that way to make the stairs less steep.

The large X is to denote the double height area over the stairs/hallway. It is a 2 storey house.
The horizontal distance is 3.3m
The floor to ceiling height will be 2.6metres, with 100mm for plasterboard and battens, and then 150mm concrete slab on top
with 75mm screed so overall height from floor to top of finished first floor level would be approx 2.925m ?


I know we have to leave 400mm from the bottom step to the Front door, but I dont have a clue on how risers and goings etc work.

if floor to floor height is 2.925, and you have 13 steps... then thats 225mm risers....
so straight away the stairs does not comply as a maximum of 220mm risers is required for a private stair.....

see table 1 here:
http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,1651,en.pdf

one winder like you have on the drawings would be acceptable in most cases... its at the discretion of your certifier....

rok

sydthebeat wrote: »

if floor to floor height is 2.925, and you have 13 steps... then thats 225mm risers....
so straight away the stairs does not comply as a maximum of 220mm risers is required for a private stair.....

see table 1 here:
http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,1651,en.pdf

one winder like you have on the drawings would be acceptable in most cases... its at the discretion of your certifier....

Thanks Syd, I'll take a look at that pdf tonight.

If floor to floor height is 2.925 and we went for 14 steps then our risers would be approx 201mm (below the maximum of 220mm).
Do you think we can we fit in the extra step? sorry for lazy question, I'm brutal at sums

Quazzie

rok wrote: »

Thanks Syd, I'll take a look at that pdf tonight.

If floor to floor height is 2.925 and we went for 14 steps then our risers would be approx 201mm (below the maximum of 220mm).
Do you think we can we fit in the extra step? sorry for lazy question, I'm brutal at sums

Am i mistaken or is there a 14th step at the top that you haven't marked in. i.e the 14th step is the landing, making it 13 steps but 14 risers.

I hope that makes sense to you.

2925 / 14 = 209 Approx which would be within regulations making the stairs in the drawing compliant. Maybe Syd or one of the others can clarify on this.

muffler

Quazzie wrote: »

Am i mistaken or is there a 14th step at the top that you haven't marked in. i.e the 14th step is the landing, making it 13 steps but 14 risers.

I hope that makes sense to you.

2925 / 14 = 209 Approx which would be within regulations making the stairs in the drawing compliant. Maybe Syd or one of the others can clarify on this.

That would be it. Its the treads that were numbered so there would be 14 risers which is fine.

rok

ah, see what you mean about the 14th step (landing), thanks for the help.
Think we will try to increase the hall way depth to > 3.3metres to "push" the stairs back a bit more and make angle less steep.
thanks again!

sydthebeat

ok, i didnt realise there was a 14th step....

so, now another problem....

if your hall is 3.3 long, assuming the stair is 900mm wide.. that gives you 2.4m for the current stair design...
2.4 m divided into 11 goings = 218mm....

minimum going for public stair = 220mm...

so if you stairs has 14 steps at 209 riser and even say 220mm going, that in itself does not comply within the maximum pitch (42 deg) because yours will be 44 deg.....

either way the hall is too small... perhaps another winder at the base may sort it....
thats what id do anyway....

rok

Thanks Syd, Quazzie, Muffler - you've been a great help.

Looks like the hall is too small, not sure if we will be able to add another winder at the base, as we may need to leave 400mm for the swing from the Front door. To make it more awkward the precast stairs company say they prefer to make "straight across" steps as opposed to tapered/diagonal steps as in the current plans.

If we flipped the way the front door opens (hinges) we might be able to add another winder at the base,
but I do not like having the stairs right in front of you as you enter the hall (what do ye think about this?)
and not sure if we still need to leave the 400mm for doorswing.
If we did flip the Front door swing it would occasionally block the door going into Study - is there anything in the Building Standards against this?

We think we will try to push the kitchen wall back 0.3metres , (unfortunately this eats up a bit on the landing space upstairs).
so then 2.7 m divided into 11 goings = 245mm

I need to go and figure out the pitch and rise properly like IamLegend2008 did earlier in thread


from Building Regulations 1997
Technical Guidance Document K Stairways, Ladders, Ramps and Guards
Landings
1.1.13 A level landing should be provided at the top and bottom of every flight except that a landing may not be necessary between a flight and a door if the total rise of the flight is not more than 600 mm and the door slides or opens away from the steps. The landing may include part of a floor. The width and going of the landing should be at least as great as the smallest width of the flight.
1.1.14 Landings should be clear of permanent obstruction. A door opening on to a landing should be so positioned that there will be a clear space of at least the full width of the flight between the door swing and the flight. In the case of private stairs, the landing at the bottom of a flight may be reduced in
length provided a clear space of at least 400 mm is maintained between the flight and the door swing

sydthebeat

1. move the study door closer to the kitchen door
2. select a front door that has the door on the left hand side and a single glazed panel to the right hand side... not a door with 2 glazed panels as you have shown. open this door back against the study wall.
3. add winders to the bottom landing, what you've added in your sketch is a full step, not a winder.
4. if the precast stair crowd cannot do winders, then dont use them.

doing the above affords you the most stair length from step 1 to step 14., without playing with moving walls.....

perhaps the attachment may be of some use to you...

how to do it without winders.... and have 250mm goings...

Quazzie

sydthebeat wrote: »

1. move the study door closer to the kitchen door
2. select a from door that has the door on the left hand side and a single glazed panel to the right hand side... not a door with 2 glazed panels as you have shown. open this door back against the study wall.
3. add winders to the bottom landing, what you've added in your sketch is a full step, not a winder.
4. if the precast stair crowd cannot do winders, then dont use them.

doing the above affords you the most stair length from step 1 to step 14., without playing with moving walls.....

Is there a need for step 2 if he does step 3?

Its understandable that a central door might be crucial to the overall appearance fo the front elevation, and moving walls might seem more appealing than change that (especially if the house is symmetrical or such)

Precast Stairs manufacturers can definitely do winders, and if they say they can't I'd be wary about what else they are not proficient at

sydthebeat

Quazzie wrote: »

Is there a need for step 2 if he does step 3?

Its understandable that a central door might be crucial to the overall appearance fo the front elevation, and moving walls might seem more appealing than change that (especially if the house is symmetrical or such)

Precast Stairs manufacturers can definitely do winders, and if they say they can't I'd be wary about what else they are not proficient at

a cleverly selected door will allow the illusion of symmetry, if that is such an issue... id move walls as the last option, if you're happy enough with the room sizes...