helping working out my pitch 15 degrees

Discussion in 'Carpenters' Talk' started by tiler7777, Jan 26, 2016.

  1. tiler7777

    tiler7777 Member

    Ok so the roof joists are 3.3 meters so how much higher does the front wall need to be to the back wall to achieve a 15 degree pitch roof?
     
  2. Phil the Paver

    Phil the Paver Screwfix Select

    around 850mm.
     
  3. tiler7777

    tiler7777 Member

    That would mess up planning regulations as the eves need to be less than 2.5meters high. Do you think I could still use 15pitch roof tiles if the height difference is 500ml? or might this cause issues I cant see?
     
  4. chippie244

    chippie244 Super Member

    If you've got tiles that need 15 degs of pitch and you only plan to give 8 degs then you are asking for trouble.
     
  5. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Surely the pitch height at 3.3m length at 15º would be 550mm?

    Mr. HandyAndy - Really
     
  6. chippie244

    chippie244 Super Member

    Not according to Pythagorous or I am really misunderstanding this which after my day I wouldn't rule out.
     
  7. Mr. Handyandy

    Mr. Handyandy Screwfix Select


    I don't know if you are or I am, but I'm thinking pent roof, not ridged.

    Mr. HandyAndy - Really
     
  8. chippie244

    chippie244 Super Member

    I'm going off a right angled triangle with a hypotenuse of 3.3M and an acute angle of 15 degs.
     
  9. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Ah, I think I been mistaking isoceles and changing the 90 at the same time.. Fk.

    Mr. HandyAndy - Really
     
  10. chippie244

    chippie244 Super Member

    I have made so many cock ups today I don't have the energy to dog you :)
     
  11. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    'Dog me' ? Urrrgh!
     
  12. Phil the Paver

    Phil the Paver Screwfix Select


    Would that matter??? 15° is 15° what ever the roof construction/design, is it not.
     
  13. Mr. Handyandy

    Mr. Handyandy Screwfix Select


    Well yeah, if the roof joists are 3.3 and a pitch roof, the pitch(at ridge) will be at 1.65 centre so completely different height.

    Mr. HandyAndy - Really
     
  14. Phil the Paver

    Phil the Paver Screwfix Select


    ????, if that was the case the joists wouldn't be 3.3 would they, as there would be two of them making up 3.3.
     
  15. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    You're probably right. I guess there would be just a minor difference for overlaps(or no overlaps) at eaves.

    Mr. HandyAndy - Really
     
  16. dwlondon

    dwlondon Active Member

    Seems like most of the tile makers don't go below 15degrees. So you would effectivey be making a flat roof, using firrings.
     
  17. tiler7777

    tiler7777 Member

    yes the roof will be pent does this affect it, e.g sloping from one end to the other
     
  18. CraigMcK

    CraigMcK Screwfix Select

    Forticrete do one at 10, but you would be lower than that too and I believe they have a vast amount of rules about using them at 10. You may need to consider sheet material
     
  19. Jitender

    Jitender Screwfix Select

    You'd have to use the inverse tan function, which is about 860mm. As you only have one length of the triangle.
     
  20. chippie244

    chippie244 Super Member

    I know how to do trigonometry, I use it most days.
     

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