Attic doors can be problematic, because they allow the temperature from the attic flow through to your conditioned space.
On a home inspection this weekend, I came across a energy efficiency problem that is more common than many people think: uninsulated attic doors. We want an energy efficient home, but when thinking about ways to improve our homes, we forget about access points, like doors, which can be a big drain on our utilities.
In the case of these attic doors, I found that the builder had installed an interior door leading to a lower attic area, and then a pull down attic door/ladder to an upper attic. Interior doors are not solid; they are referred to as hollow-core doors. The air space inside the door helps transmit the heat through the door.The pull down door is a board with the ladder attached. It is solid, but the board is a quarter of an inch thick. Not really the solid mass which will slow down heat transfer.These doors radiate their heat out into the cool rooms during our hot summers, and they draw the heat out of the room during the winters.
The pull down attic door/ladder has a simple solution for insulation. A foam insulating board with a foil covering is the best solution. If you can take off the ladder to attach this insulating board, you will obtain better energy efficiency, but you could cut out portions to fit into the spaces of the ladder. Glue these boards into place. A mechanical fastener (nail or screw) will possibly go through the door. Not a good look when seeing it on the other side. It is also a conduit for heat. To really improve the insulating factor, I would add another insulating board on top of the first one that was installed.
The attic door which is an interior door presents a more difficult challenge (maybe). Interior and exterior doors are a bit different, so you may not be able to find a door to replace the interior one. I decided to consider what I would do if I was going to keep the door. First solution: add the foam board to the side facing into the attic. I would glue this on as well, but if your glue is not working well, you could use the mechanical fastener along the edges of the door (this is where the framing/solid part of the door is located).I might tape over these fastener heads with an HVAC tape. Second solution: I would use a high density closed cell spray foam (sold at building centers and hardware stores) to fill the space inside the door. The door will have two spaces. Drill three holes along the top of the door three inches below the top. Drill three holes along the middle of the door and inch below the knob. The foam can will have a plastic tube nozzle, which you will want to fit into the holes. I imagine two to three cans would fill the doors. After this procedure, you would have a solid door.
For both types of doors, I would attach the weather stripping along the edges to assist with the energy efficiency. This stripping has a glue backing that can be pushed into place. Do not buy the thickest that you can find though. It may be too thick, so the door will not close.
Those are my ideas to help with energy efficiency of these doors. Do you have any other ideas?