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Insulating between ceiling and second level floor.


I have an old 2 story 115 year old home that is somewhat insulated. I have blown in insulation in the walls 3X5 stud, and approximately 7-9 inches of blown in the attic. But there is one location that has none, and that location is in between the first floor ceiling and second level floor. When there is a cold snap - 12C and below, or if there is any type of cold with a wind, it makes the upstairs floor very cold, plus you can feel a chill coming from the ceiling if you are on the main floor. I know that there is no insulation, because I removed a wall last year and noticed when the ceiling was open that there was no insulation in that area (up against the outside wall). Just wondering if anyone has any tips on how to alleviate this? Any suggestions would be appreciated.


MLB Construction
Re: Insulating between ceiling and second level floor.

that is normally not a space that is insulated unless it's done for sound. however, the exterior walls should be insulated in the joist bays as well as in the walls. it sounds like you have air infiltration into the joist bays from the exterior. this is one of the many reasons that people now use tyvek (or a similar product) house wrap. and or, there might be no insulation in the ends of the joist bays where they meet the exterior of the house. a little investigation would be a smart thing to do. either cut a small hole in the ceiling near the exterior wall or drill a 1" hole in the ceiling and stick a snake camera up there if you or a friend have one.

Re: Insulating between ceiling and second level floor.

Insulating older homes is tricky as older homes were usually not built the way modern homes are. Many times they have open wall cavities that travel the entire height of the building. Add ons, changes, and moved doors / windows make for interesting framing.

That being said, the overall concept you should be thinking about first is to reduce the "chimney effect" In the Chimney effect, warm air is heated, then rises. This is one reason heavy curtains touch the floor in front of a window. By sealing off the outflow of cold air at the bottom, heated room air has less movement downward from the cold windows. The same principle can be applied all over the home. Tyvek is one way to achieve this. Fiberglass insulation is another. Decent windows, foam outlet covers....

Re: Insulating between ceiling and second level floor.

I think the first issue is whether your house is a "balloon frame" or not. The way you describe the situation, I tend to think that it isn't, otherwise when you had the walls insulated, the insulation should have taken care of this area.

The belt area is usually not insulated, but it should be. The problem is that it is the most difficult area to insulate and the payback just isn't all that great. You usually have to do a lot of tear out to get at it to install batts.

If you really want to do this, I think that a foam would be the best. It will be kind of blind work, but you could put the 2" diameter hales all around the perimeter of your ceiling every 16" and have a contractor stick a wand into the hole and spray the rim joists and hope you get it all. You could check with a thermal camera to see if any areas got missed and re-spray those before you go back and plug all the holes.

You could also work from the floor of the second floor, which ever you think will be easiest to patch when the spray contractor is done.

Re: Insulating between ceiling and second level floor.

Thanks for the information, I will have to root around to see the easiet way to help fix this issue..

Old homes are a work of art!

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