Insulating Floor above Crawlspace
skyhigh82
| Posted in Energy, Heating & Insulation on
Want to insulate the floor above a crawlspace with fiberglass kraft faced batts. Area above crawlspace has oak flooring installed with nails showing through sheathing. If I use Kraft faced insulation and stuff it next to the floor sheathing and the nails puncture the vapor barrier, will this cause any issues, or is there a better way?
Replies
Insulating a cold floor
Keeping in mind that heat always moves to cold and that the floor is attached to the foundations, walls and indirectly the roof, there is a constant movement of heat by conduction from the warm air in the room to the outside via the floorboards.
A better way is to lay closed cell insulation on the existing floor, closely butted polystyrene sheets or similar and to lay a new glued t&g OSB floating floor over. This will ensure there are no drafts or heat bridges and you will save money and have warm feet.
The nails will not be a problem (other than poking you in the hand as you install the insulation).
Unfortunately, fiberglass insulation installed "open" like that loses a lot of effectiveness, but it's cheap and relatively easy to do.
There are plenty of other schemes, though most involve foam, which is going to cost more. A simple thing you can do is install the fiberglass, then cover it below with Tyvek. This will at least double the effectiveness of the insulation.