Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

Using plywood as ceiling

  • 11-10-2024 11:22am
    #1
    choppermutt
    Registered Users, Registered Users 2 Posts: 96 ✭✭


    Renovating interior of old shed. Thinking of using 1/4" plywood as ceiling rather than plasterboard. Purely for aesthetic reasons

    I am wondering is plywood permeable to water vapour and if I stain/varnish the plywood - will that effect its permeability?

    I have EPS board to use as attic insulation and a breathable membrane under the roof



Answers

  • #2
    Esel
    Registered Users, Registered Users 2 Posts: 23,091 ✭✭✭✭Esel
    Not Your Ornery Onager


    Woul it not be a fire hazard?

    Not your ornery onager



  • #3
    Lumen
    Registered Users, Registered Users 2 Posts: 31,222 ✭✭✭✭Lumen


    https://www.boards.ie/discussion/2058373810/using-plywood-as-ceiling

    I am wondering is plywood permeable to water vapour

    Yes, and more so the higher the humidity.

    and if I stain/varnish the plywood - will that effect its permeability?

    Varnish will reduce it. Stain probably won't have much effect.

    What are you trying to achieve? If you want a air/vapour barrier put one between the ply and the insulation.



  • #4
    blackbox
    Registered Users, Registered Users 2 Posts: 4,709 ✭✭✭blackbox


    Definitely a fire hazard. If you want a wooden ceiling for aesthetic reasons it should only be a facing on fire resistant plasterboard.



  • #5
    Lumen
    Registered Users, Registered Users 2 Posts: 31,222 ✭✭✭✭Lumen


    https://www.boards.ie/discussion/comment/122709320#Comment_122709320

    Yeah, but it's a shed. The point of fire resistance is to give occupants time to escape without the structure falling on their heads or killing them with smoke inhalation, but there are no occupants in a shed.

    It's not like the ply is going to spontaneously combust.



  • #6
    choppermutt
    Registered Users, Registered Users 2 Posts: 96 ✭✭choppermutt


    I have EPS board insulation which I believe does not need the vapour control layer......is that correct??



  • Advertisement
  • #7
    blackbox
    Registered Users, Registered Users 2 Posts: 4,709 ✭✭✭blackbox


    https://www.boards.ie/discussion/comment/122709411#Comment_122709411

    It may have been presumptuous of me, but when the OP said the ceiling was for aesthetic reasons, I thought it might have a high level of occupancy.



  • #8
    Lumen
    Registered Users, Registered Users 2 Posts: 31,222 ✭✭✭✭Lumen


    https://www.boards.ie/discussion/comment/122709791#Comment_122709791

    Depends really. What is the shed used for? Is it heated? If so, occasionally or continuously? Is it well ventilated? Does it have any sink or toilet?

    EPS is open cell, semi-permeable. In a heated building the vapour drive will mostly be from inside to outside, so without vapour control the vapour can condense in the insulation, which is bad.



  • #9
    Rows Grower
    Registered Users, Registered Users 2 Posts: 8,576 ✭✭✭Rows Grower


    https://www.boards.ie/discussion/2058373810/using-plywood-as-ceiling

    !/4 inch ply is not really thick enough I'd imagine.

    "Very soon we are going to Mars. You wouldn't have been going to Mars if my opponent won, that I can tell you. You wouldn't even be thinking about it."

    Donald Trump, March 13th 2018.



Advertisement