Roof on structure

Discussion in 'Builders' Talk' started by Ajaz, Jun 8, 2020.

  1. Ajaz

    Ajaz New Member

    I wood ;-) be nice if I had half the brain you have lol
  2. Jord86

    Jord86 Screwfix Select

    What, damaged? :confused:

    It's hard to visualise how things will go together, or end up, especially reading a random blokes ramblings on the internet, but honestly your roof is not a complicated one to cut on, you just need to set up a platform off a couple of trestles and planks in order to work safely, fix your wallplates down before you start and follow the method I detailed in the post above in order to get a rafter established, then we can progress from there.

    It's either that or look for a decent local carpenter in your area who should build the vast majority of it in a day but will cost you a few hundred quid.
  3. Ajaz

    Ajaz New Member

    Sorry if I'm asking redundant questions but.. I was wanting to great an over hang at the ridge end but the lower end flush inside with the timber. This is because if I create an over hang at the front the gutters won't line up and I don't want to put a bend in. Is this structurely OK. I've managed to put top plate on. No the rafters. Thanks
  4. Jord86

    Jord86 Screwfix Select

    Are you fitting a ceiling joist structure, or were you planning to leave the roof open and vaulted?
  5. Ajaz

    Ajaz New Member

    I was wanting to fit a ceiling joist structure yes.
  6. Ajaz

    Ajaz New Member

    Also what If I use hangers on the back too instead of overhang. So hangers on both ends. It will just be easier for me I guess in regards to but the cuts being made. Thanks again mate
  7. Jord86

    Jord86 Screwfix Select

    Then fit your ceiling joist structure first so it ties the opposing walls together, if needed you then have a platform to stand on once you throw a couple of boards down. Then fit your rafters, you don't have anything at the top to fit joist hangers to really, plus the rafters would want to push the wall out so you do need them to be notched and to sit tightly over the top wallplate. The bottom of the rafter can just be formed with no birdsmouth, just a seat cut and a plumb cut to suit your existing roof if you require no overhang, but you will need to bolt the rafter and joist together with a coach bolt, nut and dog tooth washer to stop the rafter pushing out under load.

    I don't mean offence by this, but it's pretty clear you've not involved Building Control with this build, and I'm not a Structural Engineer though I've built a fair number of roofs over the years, but you're quite limited by the design of your build as to what weight the roof can carry before the rafters start trying to push the walls out, so you really need to be careful, dont try to cut corners and research monopitch cut roof structures online.
  8. Ajaz

    Ajaz New Member

    Thanks mate. All your advise is being taken on board and I will do it as you've suggested. I will look at some monopitch structures online.. And 100% agree with what you're saying. It is a very big concern of mine to make sure it's solid. Thanks mate
  9. Ajaz

    Ajaz New Member

    I couldn't get a hold of 6x2 for rafters so instead bought 4x2. Will space them at 300mm for strength. Also will use noggins... So what I did was secure hangers to the top wall plate at the ridge end and cut the 4x2 to accordingly. At the bottom end made the seat cut and placed it on top of the bottom wall plate. What are your thoughts? Thanks
  10. Abrickie

    Abrickie Screwfix Select

    I think you’ve had some good advice from @Jord86 that you appear to be ignoring, joist hangers at the top of that pitch are daft and using 4x2 instead of putting the effort in to source 6x2 just awesome. FYI 300mm centres still makes the rafters undersized without a purlin
    Jord86 and PaulBlackpool like this.
  11. lukemart

    lukemart New Member

    The builder bought 600x300 man made slate tiles.. The slope was a lot less and I had to do a couple of courses at the back myself after he ghosted... The dimensions are 2.8m x 2.8m.. From back wall (starting point of slope/top end) to the lower part (door end) it measures 3.2m...
  12. PaulBlackpool

    PaulBlackpool Screwfix Select

    I am just DIY (over 50 years) built something similar using 4 x 2 roof spars but put a 6 x 2 purlin in half way.
  13. Jord86

    Jord86 Screwfix Select

    My thoughts are: you don't have a clue and are a danger to yourself.

    I've spent a fair amount of time and effort typing out details and a step by step guide for you to follow as I felt sorry for you having supposedly been let down by a builder but I can see now I've completely wasted my time and you really don't understand or can't be bothered to take on board the information I've told you. I've walked you through the process in order to prevent you possibly injuring yourself or using structurally unsound methods to build the roof, as you no doubt tried to save money by building it as a single skin structure but reading what you've wrote I may as well have just spent my time talking to the wall, and donate a few quid to the A&E department to treat you once a block falls on your head.

    Good luck.
    stevie22, Abrickie and ginger tuffs like this.
  14. ginger tuffs

    ginger tuffs Screwfix Select

    well said Jord some people dont want to listen to advise theirs a few on hear
    Abrickie likes this.
  15. stevie22

    stevie22 Screwfix Select

    You were given joist sizes way back at post 22. You can't just hope that timber so much smaller will do the job just because you put them a bit closer together. You don't even say if it's C16 or C24!

    For the record your proposal would have only around 25% of the stiffness of the 6x2s !

    You either need to change the timbers or as Paul suggests put in a purlin. An 8x3 C24 is required or you could go with a small steel.


    Jord did his last post while I was pecking away. I must say I agree with his sentiment!!
  16. Jord86

    Jord86 Screwfix Select

    It makes you wonder why on earth you bothered in the first place. I know they love a scrap, but you've got to empathize with the sparkies as to how many ninnies they have to deal with who blatantly ignore any advice they asked for in the first place.
  17. Ajaz

    Ajaz New Member

    @Jord86 hello mate. Sorry mate your advice was definitely not ignored and most definitely appreciated. Circumstances were not in my favour. Yes I would have much rather got it done but the builders did a shoddy job, left my house in a mess and ghosted.. I will make sure to get the 6x2 now. I'll make sure hangers aren't used and the notches are made. I'll use the 4x2 as joists unless they are too small for joists too.. I appreciate your time for the advice mate, even though you killed me in the last couple posts. I know you're advice is genuine and much appreciated. Thanks mate
    fff likes this.
  18. Ajaz

    Ajaz New Member

    ... And to be fair to myself, the builders that came in said single skin was fine. Also I definitely haven't tried to save money because I paid a handsome amount of money for the work they did before dissappearing, more than the work they did.. Also just to shed some light on it. The builder came in with 3x3s for the rafters with no joists and was going to use joist hangers on both ends.. Last thing the 4x2 is c24. (won't be used as rafters).
  19. Nev Hope

    Nev Hope Active Member

    Yes, your 4x2 is undersized for the joists too
  20. makaveli

    makaveli New Member

    Im pretty sure the joists won't be load bearing?
    If a seat cut is made at the bottom end of the roof rafters, the force will be going down the wall.
    I would have thought 4x2 C24 were more than adequate for the ceiling joists.
    6x2 C24 birdsmouthed at the top and and seat cut at the bottom on their own (vaulted ceiling) should be ok also. If it was me, I would add also add the joists.

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