Mounting 20kg screen to ceiling joists help

Discussion in 'Projectors, Screens & Video Processors' started by Jules Tohpipi, Oct 1, 2017.

  1. Jules Tohpipi

    Jules Tohpipi
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    Hi some advice needed please,

    I need to mount a 20kg Optoma screen to the wooden joists in the ceiling. Fortunately the joists are perpendicular to the screen, and the supplied pair of L-shaped brackets can be positioned anywhere along the length of the casing. Original plan was to screw straight into the wooden joists.

    The Optoma instructions suggest it will stay up by using four upwards-facing screws per L-shaped bracket (40mm number 5.0). There's two brackets in total.

    My best-friend builder mate is nervous. He's suggesting running some ply between the joists to spread the load, and then screw the brackets into the ply.

    I'm more than happy to follow his advice but is it necessary?
     
  2. sim12

    sim12
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    He's pretty spot on with his suggestion, there are various ways of doing this but ultimately they all involve the same method, floor boards taken up from the room above and something between the joists as already mentioned.
     
  3. jfinnie

    jfinnie
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    I would have thought the biggest concern here is that 40mm screws are much too short really. By the time you get through the plasterboard and plaster skim there is probably only the final 20mm of the screw going through, the very tip which shouldn't really bear the load.

    Get some nice long screws and make sure you get them all into the joist and not either side of it and I would think you'll be fine.
     
  4. dfdd

    dfdd
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    cavity wall rawl plug anchors will do the job without batons-have a look at ?fischer in screwfix. easier job rather than messing with taking floor up etc.
    you will be surprised how much load plasterboard can take with these fittings-have a look at this link

    Metal cavity fixing HM
     
  5. stevelup

    stevelup
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    jfinnie's advice is spot on. Long screws directly into the centre of the joist and you'll be absolutely fine. No need for anything more.
     
  6. rosco123

    rosco123
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    Hi Jules,
    I have the optoma 120" screen mounted to my ceiling now for 6yrs.
    Suitably long screws x4 e.g. 3" x 10 screws into the joist. Be aware that you might need to angle the screws slightly to get a good bite into the joist as the brackets are quite wide. I needed to do that with 2 of the screws. (1 at each side)
    Make sure to take the time needed to mount it square to the projector too.

    Regards
    Scott
     
  7. jfinnie

    jfinnie
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    I guess there is some info missing - what are the quality of your joists. I'm judging by the standards of my house which is only 30 years old and has some substantial woodwork which is in good condition. If your house were old I guess then much more attention would be merited to what you're screwing into.

    I've used these "Screw Tite" screws for several applications and they are excellent:
    Screw-Tite Pozi Countersunk Screw 5 x 80mm - Toolstation

    Even though they cut their own hole you're better off pre-drilling a small pilot first.
     
  8. rosco123

    rosco123
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    Good point jfinnie.
    Also the screen is heavy so measure and mark it all out first. Then have 2 mates to hold it in position and preferably pilot holes first then use drill/driver to screw in.
     
  9. Jules Tohpipi

    Jules Tohpipi
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    I really appreciate all the replies so far, thank you. Especially big thanks to Scott's input as he has a similar screen from the same company.

    The house is about 20 years old and the joists are in good condition. But the joist area to screw into is only about 35mm wide.

    As Scott says, the distance between the screw holes on the Optoma bracket is relatively wide, so thanks for the great tip of angling the screws (I had been worried about being near the joist edge). As for the slots themselves, 6mm thread seems the most they'll pass, though.

    When we finally go for it, I'll be meticulous lining everything up because already I see the brackets don't leave much wiggle room.

    I'll see what my builder friend says. BTW, due to access difficulties, he was suggesting having the ply on the underside of the ceiling.
     
    Last edited: Oct 1, 2017
  10. rosco123

    rosco123
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    Hi Jules,
    Your builder could mount 25mm ply in the correct position and securely screw all along into the joist (same dimensions as the screen and bracket). Then screw the screen directly onto the ply with 1.5" wood screws x 4. It will never come down. If you want further security, take two of the the screws in line with the joist out and replace with 4" screws and screw all the way through the ply and into the joist.
    Added a pic to help.

    Regards
    Scott
     

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  11. rosco123

    rosco123
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    Hi Jules,
    Another thought. I used washers with the screws. Also perhaps use pan headed screws (flat headed).

    Regards
    Scott
     
  12. ChuckMountain

    ChuckMountain
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    I am another one for centre of the joist with the right size hardware.

    I have just fitted a pj screen today and my ceiling brackets. Unfortunately my joists are parallel to the screen so I can only get one main screw in per bracket.

    I used m6 50mm self tapping bolts with a pilot hole drilled into the centre of the joist.

    Using bolts means no issue with rounded heads and they are generally more substantial.

    I then used a slightly smaller bit longer screw to go in at angle to secure out further.

    The main single bolt will take the full load anyway.

    I had previously used the same bolts with rawl plugs on the wall

    My screen weighs about 22 kg from memory.
     

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