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Author
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Topic: Folding Attic Stairways
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battic door
Posts: 6
Registered: Feb 2003
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posted 02-10-2003 12:49 PM
   
Any thoughts on energy code requirements when these devices are installed in the house? Specifically insulation value and air leakage?As I understand it, tradeoffs can be used to offset the loss of approx. 10 sq. ft of insulation in the attic floor to accomodate these devices, but what about air leakage around the door opening? The 2000 IECC requires that "all penetrations in the building envelope between conditioned and unconditioned space or outside the building must be sealed with durable caulking materials or closed with gasketing materials" (IECC Sections 502.1.4.2 and 602.1.10). How do these devices meet this requirement? Is this something typically looked at? We manufacture a folding attic stairway insulated cover - and would like your expert feedback, please. Check us out at www.batticdoor.com. thanks, mark tyrol IP: Logged |
Lou Marks
Posts: 370
Registered: Feb 2000
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posted 02-11-2003 03:27 PM
Insulate them per code. After all, if a door is used it must be insulated. Poor choice of products on design is not my problem, energy is.IP: Logged |
battic door
Posts: 6
Registered: Feb 2003
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posted 02-11-2003 04:57 PM
Insulation won't help reduce air leakage - and air leakage is what takes the conditioned air right out of the house. Fiberglass batts just filter the air as it passes right through, carrying moisture with it. Air leaks right past the attic stairway door, into the attic and outside. The key is controlling air leakage. IP: Logged |
Lou Marks
Posts: 370
Registered: Feb 2000
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posted 02-11-2003 05:10 PM
Energy codes have provisions for both issues.IP: Logged |
ba109
Posts: 588
Registered: Jan 2003
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posted 02-12-2003 07:03 AM
The drop down stair is an opening in the thermal envelope and needs to be addressed. I would place it in the same category as a skylight with regards to heat loss. It needs to be weather stripped or gasketed in the same manner as a door. By the way, I did not look at your link but I assume it's a plug for your product web site. I won't speak for everyone here but I certainly don't appreciate advertising on this web site. jmho IP: Logged |
James Zimmerman
Posts: 554
Registered: Feb 2000
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posted 02-12-2003 08:05 AM
I have a pull down attic ladder and it is located in my closet which is unconditoned space so enegry requirements are not required. Yes I know some of you might say that the closet door should be insulated but it isn't. Have you ever wondered why energy requirements are the same for a home as small as 1000 sq ft and say one of 10,000 sq ft? Which one is going to use more energy? Duh! Just a thought for all the energy gurus.[This message has been edited by James Zimmerman (edited 02-12-2003).] IP: Logged |
constructionarbitrator
Posts: 264
Registered: Aug 2003
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posted 02-12-2003 08:25 AM
BA:While I agree with you that advertising on this forum is wrong, I, for one, am glad to know that their is a sealed unit available. IP: Logged |
battic door
Posts: 6
Registered: Feb 2003
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posted 02-12-2003 01:18 PM
Dear all,My intention is not to plug the product but to discuss and learn more from the experts. I thought it relevant to indicate my reason for asking. Webmaster - please delete/edit out any objectionable references. IP: Logged |
mattw
Posts: 15
Registered: Mar 2001
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posted 02-14-2003 09:00 AM
I don't know about closets being not insulated as it is part of the heat space and as such would be required to be insulated and being in compliance with federal,state or local codes as adopted by your jurisidiction. On the drop down stairs I would agree with one person that it is an opening and as such should be gasketed and insulated as best possible, keeping in mind with the manufacturer's specification and working mechanism. IP: Logged |
twoshot
Posts: 155
Registered: Mar 2001
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posted 02-14-2003 09:10 AM
THANK YOU JAMES for a sometimes too rare voice of reason and guess what we allow pulldown stairs in res garages too IP: Logged |
constructionarbitrator
Posts: 264
Registered: Aug 2003
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posted 02-14-2003 10:08 AM
Don’t laugh, the whole concept of an energy efficient structure depends upon an airtight structure (whether that's a good idea or not is a whole other subject). During heating cycles the house is pressurized forcing the heat out (through the pull-down stairway?) and during cooling cycles the house is depressurized sucking hot exterior air in (through the pull-down stairway?). Air tightness is the primary factor in energy conservation, overwhelming any insulation R-Values or window reflective coating U-Factors (as an aside, the NFRC claims that air leakage is taken into consideration in U-Factor definition; however, I have been informed by at least one testing lab certifying windows, that they tape them up during testing to take air leakage out of the equation and that’s how you can see nearly identical U-Factors on a cheapo slider and a quality. air tight, casement). A leaking attic door could nullify nearly all of the other energy conservation efforts put into the design and construction of the structure. One leak in the bucket and all the water runs out, or more appropriately, one pinhole in the tire and the air leaks out.IP: Logged |
Gary Wheeler
Posts: 89
Registered: Dec 2002
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posted 02-16-2003 12:52 AM
"Everything is relative".What you say is good, but there are some oversimplifications in your comments that may lead some people astray. The analogy of infiltration to a pinhole in a tire, leading to failure, is poor IMHO. A better analogy may be that of a leaky bucket being kept at a constant level by a faucet. There will always be some losses by infiltration/ventilation in any building, the trick is to keep them to a reasonable percentage. One person's air leak is another person's air for breathing etc. The trick is to patch holes in the bucket (through weatherstripping, insulation) to the extent reasonable, so that you don't have to have the faucet (energy source) on too high. Keeping in mind that the bucket will always leak to some extent. It is the nature of this bucket to leak to some extent. The mention of a house being pressurized and depressurized at different times of the year is only true when looking at the house from the point of view of the attic stairway seal. The opposite condition is happening at the bottom crawlspace hatch if there is one. The effect is caused by the tendancy of warm air to rise (stack effect) and cold air to fall (reverse stack effect). For instance, in the summer, hot air from the attic will be pulled down into the dwelling (to some extent) to replace cold air that leaks out at the bottom of doors etc. Despite the common misconception that hot air always rises.
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constructionarbitrator
Posts: 264
Registered: Aug 2003
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posted 02-16-2003 10:31 AM
Gary:Both my house and my neighbor's house are similar, with the exception of the fact that I have about 125 square feet more floor space. She lives alone and works away from home, in my house I work from home (probably gone about 4 hours a day) and wife is home most of the time. My neighbor has Milgard Classic .36 U-Factor sliding windows with air leakage of .22 cfm at 1.57; I have Canadian Vinyltek .29¹ U-Factor casement windows with air leakage of .002 cfm at 75 Pascals (these manufacturers use different rating systems, sometimes I think deliberately, to avoid comparison and I don't now how the Canadian 75 Pascal’s compares to Milgard's 1.57). Her heater runs on and off all day long in the winter, and her air-conditioner cycles on and off all day long in the summer, my heater comes on for about 15 minuets on cold winter mornings, and my air conditioner comes on for about 15 minuets on hot summer evenings around 6:15 and only when the temperature exceeds 100º. My utility bills average about $35 a month year around, and her’s run as high as $350 a month in the summer. We don’t get sick from living in a sealed house, there is enough air change from going in and out of doors, and neither my neighbor nor I have attic stairways, but I would venture to say that if I did have a leaking attic stairway, the “stack effect”, combined with the pressurization/depressurization created by heater/air-conditioner cycling would significantly increase my utility consumption. BTW, I've never seen a municipal building inspector check the NFRC and AAMA labels on windows as required by the California Energy Code (not to say anything about checking proper flashing details, or even asking to see flashing manufacturers' details)! ¹ I am now using triple glazed windows out of Canada with U-Factors of .19 but they weren’t available when I remodeled my house four years ago.
[This message has been edited by constructionarbitrator (edited 02-16-2003).] IP: Logged |
aaronm
Posts: 3
Registered: Jan 2003
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posted 02-17-2003 03:39 AM
This may be a tad off topic, but why is it that some CBO's allow fold down attic stair units in attached garage ceilings? Doesn't this defeat the fire rating of the ceiling? Does anyone manufacture a fire-rated attic stair unit for these applications?Thanks, Aaron IP: Logged |
ba109
Posts: 588
Registered: Jan 2003
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posted 02-17-2003 06:48 AM
aaron,I agree. If the ceiling is a required separation then the drop-down stair needs to be treated and rated as a door. Some might argue that they are not allowed at all because openings are required to be "doors." (ref. 2000 IRC) So long as the intent and integrity of the separation is maintained, I am a happy camper. IP: Logged |
