Does the ceiling need to be insulated BEFORE the attic?

Question

Does the ceiling need to be insulated BEFORE the attic?

We are currently renovating a 1970 house with a terrace. The ceilings in the interior were originally insulated with thatch. We removed that. Now the ceilings are completely "bare," so to speak. Only the concrete blocks are visible. We want to cover the ceilings with sheetrock and consider insulating the cavity between the ceiling and the sheetrock. But we have been told that ceilings in interior spaces are no longer insulated. That annoys us. Heat does go up and then escapes through the ceiling and attic (which isn't insulated at all), doesn't it?

We also read that at least the last ceiling under the attic should be insulated. In short:

(a) Do interior ceilings need to be insulated? If so, what insulation material should be used?

b) Should the ceiling under an unheated and uninsulated attic be insulated? If yes, what kind of insulation should be used?

c) Should only the attic itself be insulated? If so, what kind of material?

Noémie Chatelain

Answers

score 2 · Answer 1 · 2022-09-15 01:15:18

You have to remember that insulation installed in the wrong place can lead to mold. That's why in an older building the walls and windows have to be considered together.

You are currently insulating on the outside. On the ceiling, then, you will get a cold roof(

score 1 · Answer 2 · 2022-09-13 06:03:51

The reed mats on the ceiling were actually only used as supports for the plaster, not as insulation.

score 1 · Answer 3 · 2022-09-16 19:27:54

I suspect it's probably a precast pumice concrete ceiling (with what beams does it rest on?); it should be easy to nail a batten there for drywall cladding; it would be more difficult in classic concrete. Consider using this substructure as a mounting level and install spotlights (or kitchen speakers, for example) there, if necessary.

Overall, I recommend enlivening the discussion with pictures of what you're talking about.

score 1 · Answer 4 · 2022-09-20 13:27:14

It doesn't change anything. Just put down insulation and that's it. Any moisture can escape through the rock wool.

– Noémie Chatelain · Answer 5 · 2022-09-11 03:27:53

Naturally, the top should be insulated (common sense). But not the ceiling from below, but the ceiling from above.

Lynda Hartstein

And is it enough to insulate just the attic floor? Is there no need to insulate the ceilings of the interior rooms? There used to be thatch there. Or did that reed serve another purpose in the past?

– Noémie Chatelain · Answer 6 · 2022-09-11 18:06:06

So I'm assuming the ceiling is wood? If you don't need an attic, I would roll 2x10cm stone wool crosswise over the attic floor.

score 0 · Answer 7 · 2022-09-29 21:52:53

Thanks for all the answers. This has definitely helped us. We will be insulating the attic, not the ceilings. We didn't know that thatch was only used to hold the stucco in place