Better Building Codes For Access Hatches
This page will collect information with hyperlinks, to inform an application to IECC for improved weatherization rules for residence access portals: attic ladders, attic access plugs and crawl space hatches. The code cycle pursued is for update of rules in 2016.
2009 IECC Section 402.2.3 and 2009 IRC Section N1102.2.3 and 2012 IECC Section R402.2.4 reads: "Access hatches and doors. Access doors from conditioned spaces to unconditioned spaces (e.g., attics and crawl spaces) shall be weatherstripped and insulated to a level equivalent to the insulation on the surrounding surfaces."
This is ignored of necessity, and local codes step in with numbers like R12, still nearly impossible to attain. All for nothing. We only need these ladders to be as good as an Energy Star exterior door.
Mike Barcik at southface.org, in Atlanta has had local success fighting this. Here is an excerpt of his message to me in March, 2014:
As we discussed in 2012, both in person and via email, Southface Energy Institute is an advocate of energy efficiency and sustainable practice. We also do lots of work with code (mainly energy code) in the southeast region. I believe that I relayed to you that I was partly responsible for rewriting the portion of the GA energy code dealing with attic access. Our amendment is below:
402.2.3 Fenestration access hatches and doors. Access doors from conditioned spaces to unconditioned spaces (e.g. attics, unconditioned basements and crawl spaces) shall be weatherstripped and insulated in accordance with the following insulation values:
1. Hinged vertical doors shall have a maximum U-Factor of U-0.20 (R5 minimum);
2. Hatches/ scuttle hole covers shall have a maximum U-Factor of U-0.05 (R19 minimum);
3. Pull down stairs shall have a maximum U-Factor of U-0.20 with a minimum of 75 percent of the panel area having (R5 minimum) insulation.
Access shall be provided to all equipment which prevents damaging or compressing the insulation. A wood framed or equivalent baffle or retainer is required to be provided when loose fill insulation is installed, the purpose of which is to prevent the loose fill insulation from spilling into the living space when the attic access is opened, and to provide a permanent means of maintaining the installed R-value of the loose fill insulation.
(Effective January 1, 2011)
I pushed for this amendment because of the way the energy code has been written (requiring the access to match the prescriptive surrounding insulation levels, a minimum of R-30 in CZ2 and up to R-49 in CZ4, depending on which version of IECC applies). In GA, we felt that as the code was written, it would encourage builders and code officials to accept stuffing an R-30 batt into the gap behind treads or laying a batt on top, neither of which would be effective. However, we could only push so hard and in the end wrote a spec for R-5 that at least one major manufacturer (Marwin) claimed they could affordably meet. We have an example installed in a test house at our training facility and it is significantly superior to a standard stairs, featuring good weatherstripping and rigid insulation. A few years ago, we had good acceptance by builders of this product and the modest price increase of roughly $30 was absorbed.
Let us now debate whether this Georgia code is the model in appeal for improved IECC code. Here are my thoughts:
1. Let us accept that the foggy word "fenestration" shall be used only where a portal is translucent, glazed, passing solar gain and a through-view. Delete the word fenestration and generalize hinged door or lift portal as "hatch", as in Oregon code, 402.2.3 Access Hatches.
2. The R-19 value required of a lift portal still invites use of a stapled gob not more likely to be intimate with plunker drywall when pulled down in closure. We must not have a barrier to use of less-expensive, factory-made portals of assured insulating value. A batt gob even at R19 adds handling difficulty, thus threatening safety.
3. Simplify remaining words to address the ideal of a factory-made panel typically with 1/8" wood facings. Let the R5 number be requirement of 1.25" minimum thickness of practical factory-cast foam used to fill non-structural space within the panel. Say structural space is limited to 20% of panel area by the Georgia prescription. The effective insulation value is then as applied in my simple Insulation Math.
1/Reff = 0.2/Rwood + 0.8/Rfoam where Rwood is 0.94 per inch and Rfoam is 4.0 per inch. At 1.25" foam thickness, R5, Reff = 3.0. This is recognizable as the claim of any inexpensive Energy Star exterior door. An access hatch might be just as necessary as an exterior door, to be borne regardless of operating cost. Operating cost of even a large 6.8 sq ft attic ladder with R5 foam fill is only about $2.63 per year by Insulation Math. Compare this to cost for the same 6.8 sf area of $0.40 if insulated to R38. If a door is made harder to configure and more-expensive by thickening foam to 2", annual operating cost is reduced by only sixty cents. The thicker door is desirable, but is not likely a better investment.
Then, complete the model code as numbered and titled in 2015 issued code:
R402.2.4 Access hatches and doors. Hinged doors and lift portals from conditioned spaces to unconditioned spaces (e.g. attics, unconditioned basements and crawl spaces) shall be weatherstripped and insulated to the standards of exterior doors.
This is the entirety of the proposed code section.
At 9/14/2015, proceed very seriously in this. I find I have a deadline of January 11, 2016, for my CODE CHANGE PROPOSAL. The proposal is an online entry at web site cdpaccess.com. I have been registered at this site for several years, but needed just a bit of encouragement from ICC, to begin to make it work.
The portal rule I wish to amend is displayed for me:
[SECTION] R402.2.4 Access hatches and doors. Access doors from conditioned spaces to unconditioned spaces such as attics and crawl spaces shall be weatherstripped and insulated to a level equivalent to the insulation on the surrounding surfaces. Access shall be provided to all equipment that prevents damaging or compressing the insulation. A wood- framed or equivalent baffle or retainer is required to be provided when loose-fill insulation is installed, the purpose of which is to prevent the loose-fill insulation from spilling into the living space when the attic access is opened, and to provide a permanent means of maintaining the installed R-value of the loose-fill insulation.
- Exception: Vertical doors that provide access from conditioned to unconditioned spaces shall be permitted to meet the fenestration requirements of Table R402.1.2 based on the applicable climate zone specified in Chapter 3.[SECTION] R402.2.4 Access hatches and doors. Access doors from conditioned spaces to unconditioned spaces such as attics and crawl spaces shall be weatherstripped and insulated to a level equivalent to the insulation on the surrounding surfaces. Access shall be provided to all equipment that prevents damaging or compressing the insulation. A wood- framed or equivalent baffle or retainer is required to be provided when loose-fill insulation is installed, the purpose of which is to prevent the loose-fill insulation from spilling into the living space when the attic access is opened, and to provide a permanent means of maintaining the installed R-value of the loose-fill insulation.
- Exception: Vertical doors that provide access from conditioned to unconditioned spaces shall be permitted to meet the fenestration requirements of Table R402.1.2 based on the applicable climate zone specified in Chapter 3.
Proposal submitted 1/4/2016:
R402.2.4 Access hatches and doors. Hinged doors and lift portals from conditioned spaces to unconditioned spaces (e.g. attics, unconditioned basements and crawl spaces) shall be insulated to the Energy Star standards of exterior opaque swinging doors, and shall be air sealed with well-fitting gaskets. The portal frame shall be sealed air tight in its rough opening.
The entry to an attic space at a portal shall have a surround of an ample raised floor that does not diminish insulation value. Flooring shall protect insulation against trampling while giving safe passage, to all attic electrical service points including fans, lights and junction boxes. Junction boxes not accessible from heated space shall be raised above insulation and flooring levels, or where this has failed, shall be flagged as a decked service point. Accessible service points shall include static vents that require periodic cleaning. Where a service point is buried in insulation, insulation over the service point shall be in batt form and tolerant of displacement for accessing the service point.
There is economy and clarification in a common insulation standard for hinged doors and lift portals, which face the same thermal challenge, less than that of an exterior door. Raise insulation standards for swinging doors, that by exception were required to only match insulation of a window, to those of Energy Star opaque exterior doors. Align the requirement for lift portals.
The higher insulation standard is U </= 0.17, Btu/h ft2·°F. The inverse of this U value is System R-value, R5.9, and is achievable in an inexpensive, safe, practical door, not more than 1 1/2” thick.
The consequences of choosing higher or lower insulation standards are small for the area of a hatch or door. For an insulated 22"x54" door with thickness range of 1" to 4", the annual cost of replacement heat has a range of only plus or minus a dollar.
The Energy Star door sealing requirement is a multiple of its area, leakage </= 0.5 cfm/ft2. This sealing requirement is far too-easily achievable, allowing average gaps 0.05", achievable even without gaskets. Therefore surpass Energy Star on sealing, requiring well-fitting gaskets. Know that the spaces between the portal frame and its rough opening must be fully filled with airtight caulk or grout, gaps not to be hidden by covering trim.
With safe access, now ensure work in an attic is also safe, and does not diminish insulation value. Weatherization has value mainly where it serves undiminished, in perpetuity. Methods and materials shall be crafted for sixty year minimum service.
(End of Reason statement in the submitted Code proposal)
Here, add statements and tables that may be found by reference in the simpler proposal, and that would burden an average reader. The simpler proposal avoids complex formatting, for ease of publishing.
CONTENDING WITH HYPE
Better rules shall at last counter false statements such as this of 1999, passed along by Habitat for Humanity, as written by southface.org: Don’t leave a hole in the ceiling : A ¼-inch gap around the perimeter of a standard pulldown staircase can potentially leak the same amount of air that is supplied by a typical bedroom heating duct (~100 CFM). Unsealed, the attic access in a home leaks energy dollars and causes the house to be less comfortable. During winter, conditioned room air may escape to the ventilated attic, while in the summer, hot attic air (which may contain airborne insulation fibers) can infiltrate into the home.
The potential leakage at an attic ladder is overstated here, times five. Responding to the hole hype, there has been surrender to impractical insulation schemes.
One way to counter the hype and move on to practical rules, products and methods, is in full demonstration of reality with math of heat transfer and leakage. I offer this applied math in web resource Insulation Math. Simple numbers are offered for common parameters: a home with 4400 65°HDD, a gas furnace 88% efficient, and energy at $2 per therm. Methods are simplified.
There is little money to be saved in extreme treatment of a small area in a home.
DISCUSSION OF ATTIC LADDER INSULATION
Consider a drop-down attic ladder 22.5" x 54", door area, 8.4 sq ft.
Thickness Reff System R U Annual Heat Cost
Bare Ceiling 3 0.33 $6.60
1" 2.0 5 0.2 $4.02
1.25" 2.6 5.6 0.18 $3.59
1.5" 3.2 6.2 0.16 $3.24
2" 4.4 7.4 0.13 $2.71
3" 6.9 9.9 0.10 $2.04
4" 9.3 12.3 0.08 $1.64
R38 Ceiling 41 $0.49
R49 Ceiling 52 $0.39
Not more than $1 per year is gained or given, within the range of practical options for an insulated door panel. A minimum ladder suited to a 2x4 or 2x6 floor is not right, where an insulated ladder should serve in a thick attic floor, minimum 2x10 door framing. With the new code, thick framing of attic entry is mandatory. A ladder with taller frame suited to the thick insulation is much stronger and has mechanical advantages in drive of door springs. As with good exterior doors, choose an attic ladder for function, durability and beauty.
DISCUSSION OF ATTIC LADDER AIR LEAKAGE
Consider a drop-down attic ladder 22.5" x 54", door area, 8.4 sq ft.
Avg Gap Path Area Qnat Qnat per sq ft Leakage Cost Convection Cost
in sq in cfm cfm/sq ft $/Year $/Year
0.01 1.5 1 0.12 $1 $7
0.06 9.1 5 0.60 $7 $7
0.12 18.2 9 1.07 $14 $7
0.25 38 20 2.40 $29 $7
This considers only the gap between the door and the ladder frame, likely less than 0.06" on average in any not-decrepit ladder even without gaskets. Conceivable leakage cost is comparable to cost of energy convection through the door.
In addition, consider gaps between the ladder frame and its rough opening. A 1/8" average gap is common here, where molding against a rough ceiling may only hide the problem from view. Plaster or caulk these gaps to easily save $14 per year or more. Know that a ladder cover in response to the hype, is useless as a seal of leakage outside the ladder frame, in addition to not sealing leakage at the ladder door.
Possible leakage, commonly allowed around the ladder, not through it, of up to 20 cfm, is one quarter the flow of a good bath fan. This is objectionable, but is little compared to 100 cfm hype.
DISCUSSION OF INSULATION IN LIFT_PLUG ATTIC PORTALS OR SWINGING DOORS
These portals will be smaller than drop-down access ladders, with less potential to save energy. Apply the same Insulation Math.
Consider example size 22” x 30”, 4.6 sq ft:
Product U System R Annual Heat Cost Cost Difference
Drywall Plunker 3 $3.68 -$1.81
New Requirement 0.17 5.9 $1.87 Ref
R49 Ceiling 52 $0.21 $1.66
Handling safety and durability of a modest plug, U = 0.17, far outweigh $1.50 energy savings potential of a clumsy, thick plug costing perhaps $100 more.