GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Dropped ceiling in bathroom for fan

joenorm | Posted in General Questions on

I have a vaulted ceiling in a small bathroom. I’d like to drop the ceiling above the tub/shower to house the exhaust fan as to not crowd insulation and to help maintain an air barrier in the lid.

That’s where I am a little confused. Is this actually a good idea? If so, how would I detail it?

It’s almost like I’d what the drywallers in first to do the sloped ceiling portion, then I’d do a dropped ceiling, then they’d either come back and do the draped ceiling or I could finish it in would or something I could manage(I’m not good with sheetrock)

Feels like I am missing something here?


GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Expert Member
    BILL WICHERS | | #1

    It sounds like you want to build small soffit to provide space for the fan. It’s not difficult to do, and is commonly done to hide ductwork in finished basements. You basically just frame out a box, then drywall over it.

    Another option you may want to consider is a wall mounted exhaust fan. This might be easier and/or less of a visual impact than building out a soffit to house a fan.


  2. joenorm | | #2

    Thanks Bill,

    There is room in the ceiling and it'd be easy to drop in a small portion. I just cannot see how I'd have the fan installed and still have the insulators and drywall guys be able to do their work around it to create an air barrier on the sloped portion of the ceiling, leaving the dropped portion without insulation.

  3. Expert Member
    Akos | | #3

    You don't need much room for a bathroom fan. You can even frame a small box around it, as long as it is high up in the ceiling it will do a good job of clearing humidity even if not directly above the shower. If you get one of the shallow ones, you can even mount it inside an interior stud bay.

    The way to do it is have the drywall folks hang all the drywall. You then tape the seams where the bulkhead will go (you can use drywall mud or 3M tape) then have the GC frame in the box and install drywall over it. The tapers then can come and finish the whole thing.

    This ensures your air barrier is continuous behind the bulkhead.

    I've attached a picture of how I did this, you can just see the box for the fan above the built in.

  4. joenorm | | #4

    I suppose I could insulate the sloped ceiling, then install a vapor barrier or smart membrane, then frame the dropped portion, then call the drywallers?

    1. Expert Member
      NICK KEENAN | | #5

      That would be my vote. I'd frame the dropped portion with metal studs, much easier working over your head since they weigh almost nothing.

      1. Expert Member
        BILL WICHERS | | #6

        They’re also trickier to connect at corners if you’re not used to working with them. Always a tradeoff :-)


  5. joenorm | | #7

    Could I use Tyvek for this? I have extra lying around. As opposed to buying a whole roll of something else?

    1. Expert Member
      MALCOLM TAYLOR | | #8


      You are trying to maintain the underside of the trusses as an air-barrier, and also hold up the insulation above. I'd be using taped plywood.

      Don't forget, you also have to provide fire-stops in the walls at the level of the lowered ceiling.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |