Insulation over pull down attic stairs

[z-man]

I have access to my attic via a pull down set of stairs in my upstairs hallway. All that insulates the opening is some plywood, probably 1/4"-3/16" thick.

Does anyone here insulate this opening? It does appear to be the largest hole I have in my home insulation, considering that my attic is well insulated otherwise and thus pretty close to the outdoor temp. I found 2 methods on-line, but did not find any threads on this board dealing with insulating the opening, only the attic itself. I like the draft cap idea since it is so easy to move in and out of place, but is an R value of 11 that good?

DraftCap:
http://www.draftcap.com/

Battic:
(broken link removed)

Thanks guys (and gals)

 

[tutu_sue]

Our attic access doesn't have stairs, but we did make a hatch door with the 2" pink rigid insulation from Home Depot. We used 4 (R-40?) layers that I glued togther with Weldbond glue and glued to a piece of hardboard we painted white. We put adhesive foam strips around the frame and used butterfly wings to hold it tightly shut. Made a BIG difference and wasn't expensive to make maybe around $30 in materials. Maybe you could make a box using the same board and use a piece of plywood on top to weigh it down. The 2" board has a value of R-10.

 

[MrGriz]

I did basically the same thing that Sue did with her attic access. Adding the insulation above the access panels made a big difference.

 

[CrazyAboutOrchids]

We have one as shown on the Battic website. It is styrofoam. It was here when we purchased the house. I do like the idea of the r-50 insulation cover on it; just may have to get that for ours.

 

[scfa99]

I actually purchased the battic door one, its cardboard and doesnt last. Wrapped in insulation it makes a huge difference. I am going to build my own out of rigid insulation and wrap bats around it. It has been written that not insulating above that opening is like having a hole in your ceiling.

 

[Rhone]

I have a program that calculates things like this. I'm assuming it's a standard attic hatch at 25" x 54" in Massachusetts. I don't know where you live, but most posters seem to live there. By creating an R10 rigid foam box over the top (it will insulate more like R11 because of dead air space) you will save you at a minimum (because I can't account for air leaks)

Heating/year
--------------------------
1,340 kW electricity ($264.78)
43.56 gallons oil ($117.18)
0.34 tons pellets ($98.92)
0.24 cords wood ($44.70)

Cooling/year
--------------------------
113.4 kW electricity ($22.40)

So R11 is absolutely worth it. The question is, is it worth doubling up the R10 foam and creating an R20 door! Actually, I'd say no unless you use electricity. The heat savings between R10 and R20 rigid foam using my rates would be

Heating/year
--------------------------
18.6  kW electricity ($3.67)
0.603 gallons oil   ($1.62)
0.005 tons pellets ($1.37)
0.003 cords wood ($0.62)

Cooling/year
--------------------------
1.6 kW electricity ($0.31)

Considering it'll probably cost you around $25-$30 extra to make it R20 instead of R10 at around $2 or less/year in savings you shouldn't up it to R20 unless perhaps you can do it for free, or maybe you purchased too much and will have waste anyway. Go buy some 2" R10 extruded polystyrene or double faced foil board (polyisocyanurate), make the cover yourself. What I recommend doing is putting some spongy foam around the opening, and using bungy cords attached to the cover, that lets you pull it down and hook on loops you added below. That forces the door to seal tight into the foam gasket making a good seal and compensates for wear & tear of said gasket. The specifics is pretty close to tutu_sue but with bungy cords & hooks to hold it down tight. BTW I purchased the battic chimney pillow way back before my insert. Dumbest thing ever, didn't work at all, battic never contacted me back when I complained it doesn't work like advertised so I'd skip the battic company. Plus, their R50 slip-on cover is a hoax. The insulation needs to be air tight and fit tight to be effective. That thing fits loose and air leaks all over it, I have doubt it's even adding R5 to it. If you want to purchase one pre-made the draft cap at R11 is the one I'd go with, you can see the savings above that even at its high cost it's a very good choice from what you're starting with and will save you a significant amount of money. You'll probably think you paid premium price for it, expanded polystyrene is white styrofoam same as the those cheap white styrofoam coolers you can get at the store and same as the styrofoam coffee cups so, you're basically buying a 3" thick piece of molded styrofoam for $150 and it probably weighs like 1 lb. I don't like how it doesn't have any fasteners to hold it in place, nor provides gaskets to stop air leaks. But, you are helping the local guy out if you buy it I'm sure the mold to create such isn't cheap. The best option is to build one yourself like tutu_sue recommended but, I'd add the bungy cords and gasket below so it pulls down tight and seals off air flow.

 

[Rhone]

Just want to say I edited my answer if you read it earlier after looking more at the draft cap.

 

[scfa99]

can you add in propane?

 

[tutu_sue]

Here is the worksheet I used to come up with my attic hatch cover: (broken link removed)

 

[Rhone]

can you add in propane?

I changed it around to use Newark, NJ as a reference place for your climate. The average price of propane in November 2006 in NJ was $2.379/gallon and I used the electricity rates from my area, yours I believe is close looking at a chart of electricity costs/state. Using an 85% efficient propane boiler/furnace the tables look like

Heating/year
--------------------------------------------
44.089 gallons saved of propane ($104.89)
256.7 Kilowatts of electricity in cooling savings ($50.71)
--------------------------------------------
Total savings/year: $155.60

If your question is, should you make your attic hatch R20 vs. R10 the difference is

Heating/year
--------------------------------------------
1.45 gallons propane savings/year ($3.45)
3.5 Kilowatts of electricity in cooling savings ($0.70)
--------------------------------------------
Total savings/year: $4.14

I'd personally make it R20.

 

[burntime]

I used r5 dow board, measured the opening then built a box with one side open. I used 2 layers of dow for the top (r10). I taped all together with aluminum duct tape. Last I pulled some r30 over the top when I crawled out. It is well worth doing, The comfort alone with Wisconsin winters makes it worthwhile. I also noticed that I could not hear the rain on the roof so it must have really been letting the warm air out Good luck and happy insulating.

 

[scfa99]

Rhonemas many thanks for computing that for me.

 

[z-man]

Thanks to everyone for their advice, and to Rhonemas for his calculations (and Yes, i also live in Mass)

I bought a Draftcap off Ebay yesterday (the mfg sells them there also), and should have it by the weekend. I plan to take Rhonemas' advice and will make sure I have it compressed down to form an air seal. My wife is quite content in our house, so it will easily pay for itself in our coming years.

The only downside is that I will burn less wood, and I have enjoyed burning so far!!