How to measure and build a new staircase...

Discussion in 'Carpenters' Talk' started by Halfaudio, Sep 28, 2020.

  1. Halfaudio

    Halfaudio Active Member

    Hello i have a task on my hands but i fear i have overestimated my abilities... And i can't just admit to my wife that i feel defeated.
    I need help measuring and calculating the new staircase so i don't screw up.
    It starts with left winder then straight up to landing left turn and straight up. I need to understand how to measure it correctly.

    I have all the materials and tools that are needed for the job except the one that types this is a bit dull.. Have 3 books that explain a lot but not fully i have a lot of experience in diy and beyond it so far have done half the house on my own.
    I don't have the money for traders because of the covid as self employers had a bit of ruff time and my kids are starting to hate the ladders..
    Much appreciated...
    Donald Rhodes and Ed Ugarte like this.
  2. Bobby Dazzler

    Bobby Dazzler Active Member

    Sorry to be blunt, but if you've got three books and are still unsure of what, and how to measure up, a few pointers on here won't help.
    As you can appreciate, a whole book can be and is written on building staircases. So anyone who's brave enough to try and condense a guide into a few posts, well good luck to them.
    Don't forget it's not just the measuring and building, there are also rules to be aware of and follow.
  3. ginger tuffs

    ginger tuffs Screwfix Select

    go on tk stairs site it gives you clues
  4. Jord86

    Jord86 Screwfix Select

    Where's SMUN when you need him?

    Firstly you need to sort those joists out at the first floor landing and fix a trimmer joist to them, possibly cutting them further back first, you may need to alter your quarter landing to suit the correct height. Measure your total rise from finished floor to finish floor, so if you're planning on having thick laminate or solid oak floorboards this needs to be taken into account. Divide the total rise by 200 to start which is an ideal height for a step, and see what it divides into, the maximum rise allowed for risers are 220mm so you can't go over this as the pitch of the stairs will be too steep and not comply with building regs. Then measure your total going and divide by 220mm which is the minimum amount allowed, again work it out until the total measurement is divisible by a whole number, there will always be one less tread than riser. You can't use the maximum rise with the minimum going as it will take you over 42 degrees which is the maximum pitch allowed for a domestic flight. Decide on your staircase width, whether you are going to build it as a closed string (so you'll need a router and jig) or as a cut string, then I would suggest laying out and marking the strings and where the newel posts will go in order to form the tenons later on. Mark your strings as a pair if a closed string stairs, then offer them side by side and check you have a mirror image with the treads and risers, if you don't then you've dropped a knacker.
  5. b4xtr

    b4xtr Active Member

    As above, there's quite a few manufacturers with websites that will work it out for you - you put in the sizes it asks for and it produces a plan with dimensions
  6. Shytot

    Shytot Active Member

    Go on Stairbox website , they have a design your stair feature
  7. SoManyUserNames

    SoManyUserNames Active Member

    Here I am!

    Sorry found a bottle of wine that needed my attention.

    If you add the overall dims to your drawings, eg. wall to wall, trimmer to wall, ffl to ffl then I can draw up a quick plan view and elevation for you. However DIY and making staircases do not really go together, many experienced joiners still get staircases wrong.
    Some diyers are better than others and I will help anyone willing to learn, so if you want to have a go please add the dims and as Jord86 mentioned, the style of staircase - cut or closed string and I will draw it up for you and guide you through as much as I can.

    Once the wine has worn off or you may end up with a spiral staircase.
    WillyEckerslike, Halfaudio and Jord86 like this.
  8. Jord86

    Jord86 Screwfix Select

    Or a loft ladder.
    SoManyUserNames likes this.
  9. SoManyUserNames

    SoManyUserNames Active Member

    Nice one.
  10. Halfaudio

    Halfaudio Active Member

    I know that i have k code downloaded and written down. They explain a lot how to build them but not exactly how to measure them when it comes to a shorter space and two left turns.
  11. Halfaudio

    Halfaudio Active Member

    I will get it done in 20 min.
    I did my own calculations but not sure how correct they will be.
    Much appreciated looks like i might end up buying you a wine :D
  12. Halfaudio

    Halfaudio Active Member

    FFL to FFL - 2652 (Rise)
    Run - 3035
    Headroom is more than enough to please code 2400 being the lowest point measured from old stairs and new ones will match pretty close anyway. (2m minimum)
    Am i right to assume this if not i will need to add headroom calculations.

    This is what i came up with
    2652/220=12.05 (220 is maximum permitted rise)
    2652/12=221 (too big)
    2652/13=204 (good in limits)
    So 13 steps and rise 204mm
    13*204=2652mm (confirmed)

    Tangent of 42 - (bein max permitted pitch angle on Domestic staircases)
    204/42 tan =226.56
    Round to 227
    227*42 tan =204.39
    Rise = 204mm Going 227mm

    Formula (2R+G=550-700)
    2*204+227=635 (Dimensions between rise and going satisfies code 550-700)

    Next should be headroom calculations but in my case it is not an issue at all.
    Is this correct or am i not getting this right?
    Last edited: Sep 29, 2020
  13. Halfaudio

    Halfaudio Active Member

    Closed stringer staircase (forgot to mention it)
    How do i add the nosing in this? 20mm would be nice but i don't understand how this affects the whole thing?

    Here is a look on my old one
    Last edited: Sep 29, 2020
  14. stevie22

    stevie22 Screwfix Select

    Are you going to see the underside? I did one in my daughters place a few years ago with a total of 7 kites but as it was all enclosed I could use very simple robust methods. I used good quality 18mm ply and drew the thing on CAD. The stringers were odd shapes so put every dimension I could, triangulating each point back to a base line then transfered this to the ply. Stringers then screwed to walls and newell posts, 2x1 battens screwed and glued to stringers and treads cut to suit, risers also 18 ply also battened screwed and glued. Nosings routed softwood batten glued and screwed. It ain't pretty underneath but I suspect the odd elephant could wander up it safely. Have a go!
    Halfaudio likes this.
  15. SoManyUserNames

    SoManyUserNames Active Member

    Hi Half,
    Just made it back into the office, I will look at this in a couple of hours.
    Halfaudio likes this.
  16. Halfaudio

    Halfaudio Active Member

    This is how the old staircase was put together except the materials were solid pine (not even engineered pine) But most of them were split the stringers were split in half and only the nails in the wall held them together. The staircase was in awful condition as soon i started to dismantle it everything literally fell in to pieces.

    I will be using couple of screws in the stringer on the wall side but nothing drastic just to hold it in place and it will be enclosed partially just where you can see the ceiling missing in picture.
    materials -
    Solid pine stringers 44mm
    Solid pine risers 20mm
    Engineered pine treads 27mm
    Newels 90mm/90mm
    Square pine balusters
  17. SoManyUserNames

    SoManyUserNames Active Member

    I have had a look at the pitches etc, your calcs are good for the rise and going, just that the space does not permit these calculations to work nicely. From the dims you have given me I think your original flight was built to the old pitch of 44º something like the image here.

    Original 44.jpg

    Depending on your district surveyor you can replace with like for like and work to the original dims, you may need to have confirmed this before removing the original flight or they may be able to confirm from neighbours houses.
    The only way I can see to stay within the new max pitch of 42º is to add winders into the quarter space landing area. as below.


    This will need a bit of extra work in making the stairs but keeps the entrance at the bottom of the flight a comfortable width and a softer pitch throughout the flight.
    The top trimmer position may move a bit from its original position but it looks as though you have already removed that.
    If you are happy with the proposed plans I will draw up the elevations.
    Last edited: Sep 29, 2020
    Halfaudio likes this.
  18. Halfaudio

    Halfaudio Active Member

    My book didn't mention how to calculate if it fits in the given space... The old stairs had 3 step winder at bottom and they were a bit steep so most likely you are right about the angle.
    I have a concern about FFL to FFL measurement.
    Do i need to add in the measurement - In first floor - underlay,carpet and on the ground level - underlay and laminate flooring?

    In that case the FFL to FFL is - 2678
    Run - 3035

    I do apologize if i had to include it.
    Yes i am more than happy with the proposed plans.
    Top trimmer position can still move forwards or backwards if needed i will add joist to the correct length when the measurements will be done.
    How will i add doors under the staircase for the little storage?
  19. SoManyUserNames

    SoManyUserNames Active Member

    No problem, all part of the learning process, there will lots more of these along the way.

    Firstly ffl to ffl is the dimension between finished floor levels to include any fixed material eg. top of floorboards or tiles etc to the same finished surface on the next floor. Any soft finishes such as underlay and carpet are not included.
    So from what you are saying you will measure from top of laminate to underside of carpet underlay.

    When measuring FFL to FFL you will need to measure from the floor area at the bottom of the flight to the floor area at the top of the flight, if the floors are out of level you will need to get a level across from the bottom of the flight to under the top of the flight and take as near verticle distance between the two as possible, I will add about 5mm for the bottom riser to allow for scribing and a bit of levelling during fitting the staircase.

    I will try to be as clear with my descriptions as possible, sorry if I come over a bit rude or demeaning but until I picked up on your knowledge I would rather explain fully than have misinterpretation.
    Halfaudio likes this.
  20. SoManyUserNames

    SoManyUserNames Active Member

    So here we go with one of my demeaning bits, The distance you are refering to total run is just a wall measurement, the "run" U.S.A. or "total going" the length of the flight through the centre line of the treads, marked in blue on the diagram.
    The reason the line comes out 1 going in front of the stair is due to the first going being part of the floor on which the stairs sit, this does not happen at the topof the flight as the landing is the first tread for the flight above when required.

    I will add these little snippets in for anyone that is thinking of building a staircase and may read this at some point.

    Going length.jpg
    Halfaudio likes this.

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