View Full Version : Help: how to insulate an attic door

Ian Gills
03-02-2009, 01:43 PM
OK. Let's see how good you guys are.

I have been stuck for years on how to insulate my attic door. It is big (57x26) but the biggest problem is the big weights on either side that stop me using an attic tent, without cutting some serious holes in it.

Any advice on what to do?


03-02-2009, 03:05 PM
One that I saw had enough room for about 1" of insulation under where the stairs folded up. Basically against the plywood that shows downstairs. That & weatherstripping around the opening worked

The only other way would be to build a big enclosure & insulate it with another door

Ian Gills
03-02-2009, 03:27 PM
Thanks Dave. I'll give that a try and also investigate a custom solution as well.

03-03-2009, 11:13 AM
Thanks for posting that picture: the unit is the same as mine! And I have been wondering the same thing, and even considering taking out the unit because of the insulation problems, even though it actually words extremely well.

Please report back what solution you put in place and how you think it works. Photos are great.

03-03-2009, 07:18 PM
I'll throw in my .02. Build a box out of 1x and screw foam board insulation to the 1x. use hinges to make one said a door.

Not that easy but I hope it gives you some ideas.


03-04-2009, 04:14 AM
I am going to guess that the seal at the edges when it is closed is poor at best...weatherstripping placed all around the edges would help seal against drafts...

03-04-2009, 07:08 AM
If it was mine, I would take the unit out. I wouldn't use the attic for storage and would try not to disturb the area at all once it is well insulated. One of the most important things with insulation is continuity. If you miss 1% of the surface area, you don't loss 1% of the insulating value, you loose 10% or more from the hole (for the whole wall). The same goes for the attic access, the whole attic can be R-50, but if the door in poorly insulated, the R value of the whole attic decreases alot. I would make the access equal to the insulation value of the rest of the attic and essentially seal it off except for emergencies. If you try to use if for semi routine storage, small acts of laziness can ruin all your work trying to improve the insulation.

good luck

03-04-2009, 03:23 PM
Chris, I appreciate what you are saying, but some of us really do need the storage space that the attic provides. If you were going to keep using it, what would you do?

03-04-2009, 04:23 PM
I would put a new stair scuttle in. You're never going to get that properly insulated without serious effort. New stair sets are not that expensive and are more efficient in terms of operation and energy also. While I was at it, I'd use a fire rated door as well. One of the last things you want is fire getting in your attic and if you can slow it down with a new door, by all means its worth it.

03-05-2009, 06:48 AM
Chris, I appreciate what you are saying, but some of us really do need the storage space that the attic provides. If you were going to keep using it, what would you do?

I would replace the stairs with a door that is easier to insulate. I would build an elevated platform that didn't impair the attic insulation for storage. Neither of these would be easy, the DOE recommends R-49 for Durham, NC. That is ~20" of insulation. You would need a chute 20" tall around the hole opening and a door at least a foot thick.

The attic is not a good storage area, you can have 150 degree temperature swings. You would be better off investing in a small storage system that is outside your house (like one of those big rubbermaid things)

03-06-2009, 07:58 AM
I like all your recommendations. I agree with them. I am daunted by them.

Daunting to think of removing everything in the attic into the house, ripping out all the flooring in the attic (3" strip subflooring, probably there since 1948), putting in new stairs, sealing all the boundaries and interfaces, putting in another 12-15 inches of insulation, and creating some dry out of the house storage. Now I know why people pray to win the lottery.

But I really do agree with you.

03-06-2009, 10:27 AM
As long as your joist structure is adequate (ie not truss construction or 2x4's, there is nothing wrong with storing things in the attic. You just have to provide adequate insulation first and a way to store items without disturbing the insulation. Your first layer of insulation (assuming fiberglass batts) should be within the joist bay. Then the second should be perpendicular in order to seal any gaps between the joists and the first layer batts. Simply build a platform with 2x10's 16" on center just like a floor joist system, put it perpendicular to the joists, put your second layer of batts around and in it, then cover it with plywood. This creates an insulated storage space.

As for the door, a new attic scuttle stair will be as I said more efficient both in terms of energy and operation. You can build a box out of rigid foam insulation and tape very easily that can be set over the stair scuttle.

The idea that you need the insulation on every square inch of space is a good one, but not practical. Providing more is always better, but you don't NEED 24" everywhere.

03-06-2009, 07:54 PM
That sounds practical and do-able. I think I have my new plan. We might actually pare down all the stuff up there, too, due to moving it out to put in the new layer of 2 x 10s.

Ian Gills
03-16-2009, 11:47 AM
Jesus Christ. There's been a lot of talk about this since I have been away.

Anyway, Scuba Dave was right. Check out my interpretation of his proposed solution. Note the weatherstripping around the outside and the 3/4" foam board squeezed between the hatch and the ladder. The foam board is held in by friction which is just so nice if it ever somes to replacing it. I bought some glue but did not need it.


I am very happy with it. It swooshes shut now. And the foam board is giving me R5.0 which ain't that bad, compared to the disintegrating fluffy stuff I had to pull out to clear the space.


It's called the Suba Dave door from now on. I am not sure about his politics but gosh this guy knows how to keep a door warm.


Foil side up since there is not an air space in this case and it looks better than the blue on the otherside.

I can't believe some of you were proposing to rip this thing of beauty out. They're ain't many ladder doors out there that can support my 260 pounds!

Some people save the whales, others save the planet. But Scuba Dave saves attic doors!

03-16-2009, 07:13 PM
Glad it worked, pretty sure it would do the trick
I actually love those older attic doors & weights
Built to last & the weights properly adjusted will really hold the door tightly closed
My last house I had a newer door & ended up having to screw the door shut - way to light weight
I'm sure there are better new doors out there, but most builders install the light duty ones
Ripping out an attic door that old should be a crime :)