Roof joists - Advice please

Discussion in 'Builders' Talk' started by Darrell Webster, Mar 14, 2019.

  1. Darrell Webster

    Darrell Webster New Member

    HI All,

    Im currently looking into using the space above the garage but the joists are way to small to accept any loading. There are 5 joists @ 600mm centres spanning 5215mm and they are 72mm x 34mm thick, without taking them out which would mean dismantling the garage ceiling what options do i have for strenghening these? any advice appreciated.

    Thanks
     
  2. gas monkey

    gas monkey Well-Known Member

    put the new joists along side the old rest on wall plate bolt to existing rafters
     
    AlvyChippy likes this.
  3. AlvyChippy

    AlvyChippy Active Member

    Had similar job while ago and it is remembered as hellish one.
    I had to fit slate tiles, instead of felt and preserve water tight ceiling underneath, 6", instead of existing 4" and double up (instead of ~600), had to fit them in between. Length was only just allowing to swing them in to the right length cuts to fit between ridge board and wall plate, but needing "bowing" to be upward had been using levers and club hammers to fit them in. Basically needed to chuck them in in pairs and reposition after wards.
    Depending if you get inspected and many other variables as for "residential dwelling" strength, I'd recommend 4"X2" and doubling the amount to reduce almost absolete these days spacing of 600.
     
  4. gas monkey

    gas monkey Well-Known Member

    what loads are we refering to
     
  5. AlvyChippy

    AlvyChippy Active Member

    Garage (shed) converted in to domicile structure has different load- strength requirements

    IE old coal storage outer building reasonable roof had to go, converting in to the kitchen and has been inspected no lesser than 3 times by local inspector, including requirement for RSJ beam etc, however appearance from outside hadn't changed at all.
     
  6. gas monkey

    gas monkey Well-Known Member

    well done not looking for a row just noisy and ment what loads was mr webster going to use
     
  7. AlvyChippy

    AlvyChippy Active Member

    Just to clarify, I used different jobs as examples.
    As for loads - need to have calculations done, in accordance to the change of structure designation... Although I have a feeling it is one of the "diy conversions" so having roof the same, ceiling the same strengthening threefold should be sufficient
     
  8. Darrell Webster

    Darrell Webster New Member

    The current rafters run length ways 17 1/2 ft long (from garage door to back wall) which seems weird, im planning on putting about 300-400 kilos of stuff up there spread out of the 17ft x 8 ft space. im asking for advice as it seems odd the way ceiling rafters are because i presumed normally they would run accross the shortest span?
     
  9. Darrell Webster

    Darrell Webster New Member

    Thanks, its just gonna be for storage above the existing garage nothing else, its the length of the current rafters that's puzzling me @ 17 1/2 long they seem to be in the wrong way round surely they should have spanned the 8 ft width?
     
  10. gas monkey

    gas monkey Well-Known Member

    pic be handy yes does seem odd
    if spread poss be ok you,ll be the first to know
    put a pic on may be able to shed more light cheers
     
  11. AlvyChippy

    AlvyChippy Active Member

    Indeed as discussion so far is in "swings and roundabouts"
     
  12. Darrell Webster

    Darrell Webster New Member

    Hes a pic looking to the garage door, its exactly the same behind me.
    20190314_194937.jpg
     
  13. AlvyChippy

    AlvyChippy Active Member

  14. gas monkey

    gas monkey Well-Known Member

  15. Darrell Webster

    Darrell Webster New Member

Share This Page