Ceiling joists - where are they?

Discussion in 'Carpenters' Talk' started by ennaress, Dec 21, 2005.

  1. ennaress

    ennaress New Member

    I'm trying to find a smart way of locating the joists above a bedroom ceiling so I can attach bolts to them. Access from the floor above is not practical. The ceiling is board and plaster only. It's a Victorian House so I guess joists run at 400 intervals? But how do I track them without possibly hitting pipes / wires which I know run around there? Any trade hints / tips please? Thanks. Nick
  2. Jim

    Jim Guest

  3. nigel

    nigel Guest

    Push a skinny screwdriver thru at the edge of the room and locate first timber , measure of 400mm and try again till located move across untill all are located. If the driver is short it cannot reach any pipework or wiring and will not pierce anyway.The type of locator suggested are easily fooled by debri and lathe and plaster ceilings.
  4. dewaltdisney

    dewaltdisney New Member

    I have the detector shown and used it this week and it was c* at finding joists in a lathe and plaster ceiling. (I only paid £5 for mine in Aldi a few months back)

    It is really hard finding the joists and a slight deviance in the centres, common in older properties, puts your measurements all out. I went up in the loft area and drilled through next to the joists and even then wandered off when screwing the PB doing overboarding.

  5. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Tap, tap, tap, tap, thud, thud, tap, tap, tap, tap, thud, thud................

    One way!

    Mr. Handyandy - really
    Samsenna likes this.
  6. ennaress

    ennaress New Member

    Thanks Mate - very helpful, I'll try that. Ennaress
  7. ennaress

    ennaress New Member

    I like the tap tap idea! Let's hope I get more taps than thuds! Thanks all
  8. ennaress

    ennaress New Member

    Thanks - but do they work for wood?
  9. Trip-Lock

    Trip-Lock New Member

    no, just polystyrene joists
  10. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Thanks - but do they work for wood?

    Yes, they do work for wood.

    You have to spend a bit of time calibrating it first.

    Use the tap, tap method to find what you are sure is just plasterboard, place you sensor up to it, and adjust the thumbscrew so that it beeps, then turn it back so that it JUST stops beeping.

    You are set. Then, everything you pass over that is more dense than just plasterboard, it will beep. Pass it across a couple of times, and you will not only find the joists, but should be able to find the width and the centre of it.

    Make sure you are on the 'stud' setting, as the cable and pipe setting searches in a different way, and won't help at all.

    Just as quick to use the tap method with a knuckle sometimes, but you can get tap tap if a nail isn't holding the plasterboard tight to the joists.

    Also look for slight cracks in the ceiling. These might run all the way along the edge of a sheet of plasterboard, and all along that edge MAY be a joist. Good place to start.

    Mr. Handyandy - really
  11. Jimbo

    Jimbo Screwfix Select

    love to comment about polystyrene joists
  12. ­

    ­ New Member

    At the Hirex show a couple of years back there was a display for a company selling top of the range studfinders.

    They had a special stud wall built for the display and in this wall were the timber studs (obviously) plus copper pipes, live cables, dead cables and anglebead. The idea was that you could slide this sensor along the wall and it could detect what was where.

    Well I had a go and even knowing where the pipes and cables were (there was a perspex section to the wall to show you) it could not detect jack ****!

    This thing just beeped at random, pass it over the beep area again and...... nothing! What a waste of time and money. No way could you rely on the beeps to tell you anything other than you had just wasted a few quid.

    Now there is an even 'better' one made by Bosch. My tool supplier had them on demo and once again it was useless. This was about £450 too!

    It's incredible that nobody can make a RELIABLE detector.
  13. dirtydeeds

    dirtydeeds New Member

    ive a detector, not much good although i spent £60 on it. it detects lots of stuff all at once so its useless to me

    i just wish i could switch it to detect one thing at a time. ie timber, pipes and cables
  14. Bitty

    Bitty New Member

    Hello ennaress.

    If you have access to a cheap detector which also has a 'metal' option on it, then use this option. You should be able to detect the plasterboard nails - I've found this more reliable in the past than trying to detect the studs themselves.
  15. fishthechippy

    fishthechippy New Member

    Rip the whole bl**dy ceiling down and start from there, slightly more work but good fun all the same!
  16. fannyboz

    fannyboz New Member

    Chances are it's a lath and plaster ceiling in which case they should be at 13 inch centres. I would suggest a light tap with your hammer and listen for the different sounds. I've been doing this for years and usually find them this way. Remember that the joists as a general rule will run from the front of the house to the back.
  17. fannyboz

    fannyboz New Member

    Sorry make that 18 inch centres. It would be 13 inches on a lath and plaster wall.
  18. dirtydeeds

    dirtydeeds New Member

    fanny boz, why was 13inches used for lath and plaster, the old boys generally had a reason for doing stuff

    for instance we use 400 or 16inches on studding, depending on the sheet size that will be used

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