How to Insulate Attic Drop Down Access Stairs
Attics and Basements, Heating and Cooling, Insulation by Danny Lipford
Even if your attic is well insulated, the folding stairs that provides access can be a major source of heat loss. They often are poorly sealed and provide only a thin piece of plywood to keep the heated air from escaping.
Begin by checking to see if the attic stairs close tightly then apply self-adhesive foam weather stripping around the perimeter where the plywood door meets the frame, except on the hinge end.
Once the opening has been sealed, it can be further insulated by building a foam box in the attic to enclose the stairs.
Materials for the project cost around $30. Here’s what you’ll need:
Materials List:
- 1 – ¾” x 4’ x 8’ sheet rigid foam board
- 1 – 2” x 30’ roll foil duct tape
- 2 – ¾” x 17’ roll foam tape weather stripping
- 1 – tube caulking (optional)
Be sure to use foil tape since regular duct tape won’t hold up to the heat in the attic.
Start by measuring the dimensions of the opening.
And the height the stairs protrude above the attic floor.
Using a utility knife with a straight edge as a guide, cut strips from the sheet of foam to form the sides of the box. For best results use a new blade so it will cut the foam cleanly. Make the strips an inch or two wider than the stairs extend above the attic floor.
Finish the cuts by bending the piece and cutting from the other side.
Cut the strips to length to form the box using a framing square as a guide then join the corners with foil tape. A bead of caulking can be applied as well to form a better seal.
Attach foam tape weather stripping to the top edge of the box to form a tighter seal. Cut a piece of foam the size of the exterior dimensions of the box for the lid. Tape the lid to the top of the box along one of the long edges with foil tape.
Clean the floor around the attic stairs so the tape will adhere well. Position the box over the opening, making sure it is square.
Attach the box to the floor around the outside with strips of foil tape then run tape along the entire edge.
A bead of caulking can be applied around the inside of the opening to provide a better seal.
Finally, remember to close the lid when you leave the attic.
For those who would prefer to purchase a premade cover, the Attic Tent™ is available in several sizes to fit different openings.
17 Comments on “How to Insulate Attic Drop Down Access Stairs”
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February 8th, 2008 at 18:40
How To Reduce Your Heating Bills This Winter / Energy Conservation Begins at Home
Imagine leaving a window open all winter long — the heat loss, cold drafts and wasted energy! If your home has a folding attic stair, a whole house fan or AC Return, a fireplace or a clothes dryer, that may be just what is occurring in your home every day.
These often overlooked sources of heat loss and air leakage can cause heat to pour out and the cold outside air to rush in — costing you higher heating bills.
Air leaks are the largest source of heating and cooling loss in the home. Air leaks occur through the small cracks around doors, windows, pipes, etc. Most homeowners are well aware of the benefits caulk and weatherstripping provide to minimize heat loss and cold drafts.
But what can you do about the four largest “holes” in your home — the folding attic stair, the whole house fan or AC return, the fireplace, and the clothes dryer? Here are some tips and techniques that can easily, quickly and inexpensively seal and insulate these holes.
Attic Stairs
When attic stairs are installed, a large hole (approximately 10 square feet) is created in your ceiling. The ceiling and insulation that were there have to be removed, leaving only a thin, unsealed, sheet of plywood.
Your attic space is ventilated directly to the outdoors. In the winter, the attic space can be very cold, and in the summer it can be very hot. And what is separating your conditioned house from your unconditioned attic? That thin sheet of plywood.
Often a gap can be observed around the perimeter of the door. Try this yourself: at night, turn on the attic light and shut the attic stairway door — do you see any light coming through? These are gaps add up to a large opening where your heated/cooled air leaks out 24 hours a day. This is like leaving a window open all year round.
An easy, low-cost solution to this problem is to add an attic stair cover. An attic stair cover provides an air seal, reducing the air leaks. Add the desired amount of insulation over the cover to restore the insulation removed from the ceiling.
Whole House Fans and AC Returns
Much like attic stairs above, when whole house fans are installed, a large hole (up to 16 square feet or larger) is created in your ceiling. The ceiling and insulation that were there have to be removed, leaving only leaky ceiling shutter between the house and the outdoors.
An easy, low-cost solution to this problem is to add a whole house fan cover. Installed from the attic side, the whole house fan cover is invisible. Cover the fan to reduce heating and air-conditioning loss, remove it when use of the fan is desired.
If attic access is inconvenient, or for AC returns, a ceiling shutter cover is another option for reducing heat loss through the ceiling shutter and AC return. Made from R-8, textured, thin, white flexible insulation, and installed from the house side over the ceiling shutter with Velcro, a whole house fan shutter cover is easily installed and removed.
Fireplaces
Sixty-five percent, or approximately 100 million homes, in North America are constructed with wood or gas burning fireplaces. Unfortunately there are negative side effects that the fireplace brings to a home especially during the winter home-heating season. Fireplaces are energy losers.
Researchers have studied this to determine the amount of heat loss through a fireplace, and the results are amazing. One research study showed that an open damper on an unused fireplace in a well-insulated house can raise overall heating-energy consumption by 30 percent.
A recent study showed that for many consumers, their heating bills may be more than $500 higher per winter due to the air leakage and wasted energy caused by fireplaces.
Why does a home with a fireplace have higher heating bills? Hot air rises. Your heated air leaks out any exit it can find, and when warm heated air is drawn out of your home, cold outside air is drawn in to make up for it. The fireplace is like a giant straw sucking the heated air from your house.
An easy, low-cost solution to this problem is to add a fireplace draftstopper. Available from Battic Door, a company known for their energy conservation products, a fireplace draftstopper is an inflatable pillow that seals the damper, eliminating any air leaks. The pillow is removed whenever the fireplace is used, then reinserted after.
Clothes Dryer Exhaust Ducts
In many homes, the room with the clothes dryer is the coldest room in the house. Your clothes dryer is connected to an exhaust duct that is open to the outdoors. In the winter, cold air leaks in through the duct, through your dryer and into your house.
Dryer vents use a sheet-metal flapper to try to reduce this air leakage. This is very primitive technology that does not provide a positive seal to stop the air leakage. Compounding the problem is that over time, lint clogs the flapper valve causing it to stay open.
An easy, low-cost solution to this problem is to add a dryer vent seal. This will reduce unwanted air infiltration, and keep out pests, bees and rodents as well. The vent will remain closed unless the dryer is in use. When the dryer is in use, a floating shuttle rises to allow warm air, lint and moisture to escape.
If your home has a folding attic stair, a whole house fan, an AC return, a fireplace, and/or a clothes dryer, you can easily, quickly and inexpensively seal and insulate these holes.
Mark D. Tyrol is a Professional Engineer specializing in cause and origin of construction defects. He developed several residential energy conservation products including an attic stair cover, an attic access door, and is the U.S. distributor of the fireplace draftstopper. To learn more visit http://www.batticdoor.com
February 13th, 2008 at 23:02
I have a visual of heating and or cooling loss through thermal infrared. The dramatic temperature change is incredible when you can see what the above article is refering to.
John Cannamela
http://www.infraredsurvey.com
Charlotte, NC
September 4th, 2008 at 22:08
I purchased the attic tent from AtticFoil.com. I searched everywhere and they had the lowest price. Only $138.95 http://atticfoil.com/attic-tent.htm It made a huge difference in my home since the thermostat was right under the attic door.
October 29th, 2008 at 07:49
I rather spend $20-$30 for the foam
November 9th, 2008 at 21:00
Nice fix. I was just wondering if this is a code violation.
January 23rd, 2009 at 13:47
I made a box out of the rigid foam board and just slide it over when going into attic. less prone to damage carrying things up and down stairs.
January 26th, 2009 at 13:13
I built a lightweight door out of .25 inch plywood and 1×3 pine. Then I added r-19 insulation to upper side and sealed it with radiant barrier insulation. I built up the opening with 2×4’s and used corner braces to hold them in place. The final piece was caulking the 2×4’s to the plywood floor and adding radiant foil to the inside of the door and sides.
All in all, the door probably cost me $50 but I got R-19(+) instead of r-7 or whatever.
February 10th, 2009 at 13:08
Whichever way you decide to insulate the attic hatch/stairs, do not forget to insulate the gap between the rough opening and finish opening with the “blue-can” foam. Otherwise, huge air leaks still occur around the hatch/stairs.
July 2nd, 2009 at 15:32
Hay Frank, i wonder if you can post a picture of what you made. sounds like a great idea. Thanks
July 12th, 2009 at 16:57
I’m w/ Simon, Frank can you send us a photo.
I’ve been thinking of this for some time and don’t want to spend $130 on this project. The materials for the “Attic Tent” look like they should cost about $30.
July 27th, 2009 at 14:43
[...] I’m thinking about building one of these. I have a 1/8-1/4 gap where the attic stairs are at in the hallway and I’m sure that is letting some hot attic air into the house. Hopefully this will work….its a fairly cheap project. DIY: How to Insulate Attic Drop Down Access Stairs – Danny Lipford [...]
August 20th, 2009 at 08:19
We offer all our stairs with the option of a thermo panel attached to the door, as well as weatherstripped. Ask you local supplier for Memphis Folding Stairs
November 19th, 2009 at 14:10
What if your attic stairs are not flush with the floor of your attic? Our attic stairs are surrounded by a frame of 2×6s on edge, and other 2×6s meet this “box” (without top or bottom) from the outside. The floor of the attic is almost like a grid of 2×6s, narrow edges up. How would you fit something over that?
January 11th, 2010 at 17:27
Last night I bought an Owens Corning insulator for $42.00. Just open it up in the attic & place over the opening. All drafts were gone. The temperature last night was 12 degrees, this morning I pulled down the stairs and they werent even cold. Great buy and less of a hassle.
March 21st, 2010 at 14:43
For your problem with the thermostat, manufacturers make them where the temperature sensor can be placed in a different location than the operational unit. This can alleviate any spots in a home that are not ideal for an accurate temperature reading.
August 25th, 2010 at 15:13
I mounted a two by four to one end of the access, just outside the molding. Attached a 3/4″ insulated foam board to a piece of 1/2″ plywood, which I cut to match the outside dimensions of the molding around the access, and screwed the plywood with the foam so it covered the opening, and attacted hinges to the two by four and plywood, so when I want to go up, I just unscrew it and the plywood hangs down, then I pull the ladder down.I provides a much better seal, and I can add some trim around the edge of the plywood to cover the foam.
Ben Erickson Says:August 26th, 2010 at 10:08
Hi Joe,
Sounds like a great solution, thanks for sharing it!