I've got a basement room that is not connected to the rest of the basement, is not heated and has poor insulation. Our living room is right above that basement room. The ceiling/floor between the two rooms is concrete and the only insulation between the two is a drywall ceiling in the basement room that is dropped about 4cm (~1.6in) + plaster.

The two rooms are well enough connected so you can smell solvents in the living room from paint drying in the basement.

The basement room is pretty low already, so the amount of insulation will be limited.

My question is:

What's the best way to insulate the basement from the living room?

Options I've been considering:

  1. Tear down the drywall ceiling, replace with styrophoam/rock wool panels.
    Pros: good insulation, DYI.
    Cons: a lot of work to destroy something that's already there, styrophoam and rock wool potentially release toxic/carcinogenic material. Relatively expensive. Styrophoam adds to the fire load in a basement storage room.
  2. Blow-in insulation.
    Pros: I can use what's there; it's probably a matter of minutes to get installed. Good, cheap, non-toxic, eco-friendly, flame retardant insulation material.
    Cons: I don't think that's something I can do myself without expensive equipment and without the experience, can I? It may be hard to get a professional for such a small job.
  3. Spray foam.
    Pros: Cheap, easy DYI(?), good insulation, non-toxic once dry, flame retardant when using the right foam.
    Cons: I haven't read much about using spray foam for drop ceiling insulation, so I don't know if this is practical and what the potential pitfalls are.

What other options am I missing? What other Pros/Cons am I missing with the options I've listed?

  • I think, photos and/ or a plan may help. Commented Apr 21 at 10:34
  • Are there openings between the basement room and the living room? A concrete ceiling/floor should stop most smells from passing though, much better than adding insulation. Insulation should help in keeping the living room warmer, but smells can go though some insulation.
    – crip659
    Commented Apr 21 at 11:21
  • If smells are the issue , then venting is needed rather than insulation.
    – RMDman
    Commented Apr 21 at 11:32
  • 1
    Blown-in the machines are easily available for rent from tool rental places and/or the same places that sell insulation. Spray foam the trick is not to blow out the plaster ceiling as the foam expands, while having enough foam to expand and fill the space; but it's the only one that might seal the gaps between the rooms allowing airflow now, unless you address those with caulking from above and below as a separate operation.
    – Ecnerwal
    Commented Apr 21 at 15:13
  • @RMDman No, the smell isn't the issue; I just mentioned it to describe the situation and to explain why I'm sensitive about toxic materials. Commented Apr 21 at 16:35

1 Answer 1


The only really good reason to insulate basement ceilings is if the floor above them is unpleasantly cold and you don't want to throw down rugs or wear skippers. Hot air rises, and the basement is usually cooler than the ground floor so there isn't a lot of downward heat loss.

If you do want to save energy, air-sealing the foundation and walls and insulating the attic are the best bang for the buck. After that, insulating the basement/foundation walls will usually do more to reduce net heat loss than insulating the basement ceiling, and will make the basement more comfortable too.

But if your local utility company will subsidize insulating the basement ceiling, it certainly doesn't hurt.

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