Mandatory Attic Access Walkways

I submitted the following among proposals for 2018 revision of the International Energy Conservation Code:

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 standard says: U-Factor ≤ 0.17)

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.

Existing code of 2015 says:

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. 

All of this, and supporting statements offered to conference readers, is summarized in page Better Building Codes For Access Portals, at my web site r5portals.

I defended my proposal at 2016 Committee Action Hearings of the International Code Council in Louisville, KY, on April 18, 2016. There was expressed disdain in the matter of insulation value of a practical hatch, that I cited rival Energy Star standards, and no acknowledgement of my comprehensive math proof, that modest insulation is best; more on that elsewhere. Here, address the second-paragraph flooring requirement, forcefully opposed by one of the rotating intervenors of the National Association  of Home Builders. I took this opposition as formidable, in judges unanimously disapproving my proposal. Several participants privately encouraged me to persist in this and some of my other proposals, but no one came forward as an ally, to help if I would double my onerous personal investment, to offer and defend revised proposals, in Public Comment Hearings, Kansas City.  Those "final" hearings were concluded a week ago, and I was not there. To not feel defeated, I must believe that I am intent upon readiness to try again in the next of the three-year code cycles; then having time to enlist allies.

Here, add defense of the second paragraph of my proposal. I have a really-good example to share, of work done in Oregon City, Oregon June to July, 2016. A customer had discovered that large areas of the attics in his two-year-old home had no insulation. Hard to believe, but evidence showed in zonal early frost melt on the roof, unlike neighboring homes. 500 sq ft was bare, some seen in this view.  I suggest that a mandatory walkway here and an access cut further on, would have led to different and better construction choices. Impaired access is not good, for anyone.

In this photo see beginning of rapid and easy change. The scattered temporary plywood is important to my safety. I have cut down a horrible 16"  OSB skirt about the small access hole.

Move interfering HVAC ducts, and temporarily detach a bath fan duct. Separate HVAC flex ducts at a wye, and move them under the diagonal truss members.

Many trips are needed along a new smooth and level walkway, upon 32" bridges of truss elements. Cut batts to fit, in the garage, and carry pieces in a growing collection of empty insulation bags. A safe passageway should not be an afterthought. Many good things, not least worker safety, result from good access. Let access be lighted too. At least, let workers find power outlets to not rely on a flashlight.

In this access exercise, learn some lessons about HVAC duct installation, attic ventilation and a further thoughtless neglect of access. Preserving duct length is very important as ducts are disassembled and reset. Yet, I must sacrifice about 6" from each flex duct at this wye, because of remnant bad advice of PTCS trainers in the service area of Bonneville Power Administration. Goop, no longer required, should never be applied for liner attachment.

Goop applied blindly and in risk of clothing, missed this under-side zone of the main branch of the wye. There was duct leakage, out of sight. UL181 Nashua 557 tape easily achieves zero leakage here, and is the right choice for easiest damage-free separation of ducts for maintenance or replacement. Know that flexible ducts have claimed useful service life of not more than ten years . See example of Thermaflex ducts as fallen-apart rat paths after about 25 years .

I know that regardless of found condition, I must replace cardboard soffit vent baffles. They rarely survive more than thirty years and when used are with no manufacturer thought or guarantee of acceptable service life (sixty years!). Here I have more than conscience in play. Curl with detached flimsy staples is ugly. Looking down at vent bird block, see poor bird block design employed by most builders. Slot placement demands vent baffles 3 1/2" down from roof sheathing, a large sacrifice of potential insulation depth over exterior wall headers. This bird block is needed in every available roof joist bay, not in every fourth.

Lumber for proper soffit vent baffles is free, in good employment of job scrap. Use 25 cents of good deck screws, not nails. I assembled six baffles in thirty minutes. This is quicker than setting a $1 cardboard baffle, thus less expensive. Wood sleds are easily adapted for obstructions, then set much more securely.

Baffles just 32" tall are ample over R45 batts. I can push R30 top-layer batts tightly against a baffle, for fullest insulation value, and that is the controlling economy.

A hidden attic around this corner was uninsulated too. The triangular access is new. Opportunity was concealed behind redundant OSB sheathing.

While I am at this I will insulate over the garage too, to just R15. I can't bear to crawl there carrying insulation, through this jungle of beam and variable trusses.

Cut in a new access for the garage, "factory built" in my shop. Where truss bottom elements are 2x4, they must not carry loads unless strengthened as composite beams. Leave a couple of 9" rips of plywood that I needed for my safety, but not more flooring.

Here is the fully-dimensioned plan of my hatch, offered to anyone as noted here.

At June 18, 2021, I revisit this post upon reading the post of this date at Insulation Institute Blog: A Hot New Home and Missing Insulation. I see that this post should go further upon process of inspection, not just means of inspection. Process should be for information to the builder and ultimate home owner and not just a manager of building permits. Building permits delve in the short-term self-interest of a builder, to get a certificate of occupancy. They involve inspection requirements  often flouted. by disinterested and unmotivated municipal employees, who take an easy path where inspection is difficult or impossible.

Get better results where inspection is primarily in service of the self interest of the home occupants ever-after. Those citizens of the community  are the real employers of the inspectors. Let these employers then receive indelible proof of critical performance items in the form of pdf documents I call Diligence Reports. A diligence report is created by a professional technical writer rated for integrity and skill in taking photos and notes from the builder daily to generate each required Diligence Report. Report contents are driven by task checklists, and comply with simple national standards. The involvement of three parties in the satisfaction of checklists ensures honesty. 

A recent customer was fascinated with the notion of Diligence Reporting, and made this hat for me! 

I wondered when I would first find cause to share the humor.

Where Failed Flex Ducts in a Crawl Space Were a Magnet to Mice and Rats

This is what happens when R19 kraft-faced batts are stapled to floor sheathing, in a crawl space with framing 4x8@48, so hard to insulate. Twine everywhere just densified the jungle. It was much worse before a couple of rounds, carting away fallen-down batts; really ugly.

Many generations of mice thrived atop the kraft facing and in falling-down caverns.

Half of the batts did not share this decrepitude, sadder then to pull them down for disposal.

About 1200 gallons of compacted batts were sent off to an Eastern Oregon landfill, via this transfer station and rail cars. This is one carload of 250 gallons, a crime, but nothing compared to a mountain of plastic foam that should have had an alternative use.

HVAC ducting came into view, this an awfully-leaky 14" return line. All other ducts were Thermaflex flex, far more to be hated, as probably the major cause of the vermin infestation, the magnets of the post title.

The flex ducts were to be hated for their thoughtless construction. Here a duct is partially detached where it stressfully ducked under a water pipe.

In imagining how to craft vermin-proof new crawl space insulation, consider a romex lead to a living room floor outlet. A competitor suggested  spray foam, nicely ruled out by the wiring obstruction. At about this time I would confront a ruined very-expensive home in a  sad bid visit, uninhabitable due to stink of foam, white hardness coating even the ground.

Horrible decrepitude of the flex ducts was not easily seen. A Northwest corner of the crawl space, least accessible, was littered with rat traps. Why?

Where my discoveries began in Mid-July, 2015, my mandate was just to fix the ruined insulation. I spent part of a day pulling down batts. Then I brought lumber and insulation, to try out a method that had been on-my-mind for years. Here it is:

And with adjusted attitude and method, it works. But, what of interfering ducts? I'm told I must cope with them. I have impending family travel, and a Summer of air conditioning is wanted. I will return, and will find workable paths, in Early-October.

It is late-September, and I will attack the ducts, not really authorized. This is the near duct I had crushed, thought to be attached OK. The liner has a leak, but there is much worse. See the detached spring coils? All Thermaflex ducts in this home are of an early, brittle polyethylene formula. Wires are detached. There are associated liner rips, everywhere.

I expected decrepitude at the thoughtless runaround of laundry water pipes. Curse that damned "duct tape!"

See lots of leakage in the steel piping. See a large separation in the plastic liner, that had been hidden but not blocked, by insulation lining.

See more detached wire, and holes everywhere, inside the flex duct.

Everywhere, is not much exaggeration.

A D-box is a hydraulic monster, itself with usually-leaky attachments.

Incredible.

And, Thermaflex will poo poo, chemistry from mice somehow caused this.

This was the main entry to ducting by rats and mice, then having access to the house interior. The foulness of the liner is evident. Yet a pest abatement contractor spliced in an oversize aluminum flexible duct as the sufficient cure years ago.

Within the insulation lining, not before explored, I found this. The stick was within the air path. With the report I found immense home owner gratitude that I had insisted on demolition and re-imagined ducts.

Crude D-Box tab-in collars can not be sealed.

An insulation-lined turning box replaces the D-box. Use springy lumber to gently find alignment.

A found strap is useful, the rest of the demolished D-box is recycling.

A 16-12-12 wye was an obvious need in this alternative to ridiculous job-hacked D-boxes. Aligning it for clearance of a nearby post is challenging. Begin to see thick flexible grout coating inside all unlined steel fittings, to isolate them somewhat from temperature cycles of carried air. If the steel does not fully swing with air temperature, it has important reduction of thermal mass. Most of the volume in flexible grout is insulative ceramic microballoons.

In a chosen wye orientation, bring on insulating wrap, and secure fittings with screws and UL181 Foilmastic tape.

Some of the weight of steel components is borne by cantilever from the turning box and furnace. Most weight is carried by taut wires at joining pieces. The wires attach to eye bolts in the sreel fittings and to eye screws in the beams above. The ample reserves of insulation jackets are rolled into place as duct assemblies are completed.

In advance of each joining, pull on ample lengths of insulation jacket. Jacket should fully cover all steel and insulation.

Work now with the left-side 12" branch of the 16-12-12 wye. There is a quick 6" wye take-off to a register.

Note the excess liner lengths needed to contain all steel, insulated, out of sight.

Please rely on this diagram of the as-built ducts, to locate the work in following photos.

This attachment to a 12-12-6 wye is with necessary change of direction. Pull quite a bit of tension to limit flow resistance. Call the axial taping strain relief.

Here is finished appearance at the 12-12-6 wye, in a high-traffic area. Interleaving insulation and wrap from two directions can be bumpy.

This is the previously-hated low Northwest corner of the crawl space, close up. Leaving at end of an October day, the furnace is back on and all but two registers are served.

Back in the Northwest corner, for some clear-headed, intense duct construction.

Ducts all done, but to rework a branch warming the kitchen. I will leave some of this now-dirty OSB, though I don't expect ever to return.

Here is the Northwest corner at a distance, now not foreign or hated. I see the rocky dirt as dry. I will not bother to pull up ill-fitting black visqueen, over the rocks and concrete piers.

Survey the completed ducting, starting at the furnace. Yes, there is a rat trap down there, never to be needed again, soon to be gone and forgotten. Everywhere there is smoothness overhead, and I have been under there in the duct-running.

North wall alley. Just duck under, to get past the furnace.

The 16-12-12 wye at the furnace nicely split about a post. All weight is carried by duct steel fittings with topside eye bolts, tied by wires to the beams above.

The 12" branch toward the kitchen is pulled over vent piping, off the ground, without much flow resistance at a formation to oval.

The house had a single 7" register for the kitchen, laundry and a little bathroom. Sadly resigned that can't be improved, minimize resistance to the 7" register, new, firmed-up. 8" flex duct transitions through a 7" reducer.

Kitchen HVAC duct finally done. In the distance, I will now finish an obstructing 6" duct from the kitchen grill and fan. Overhead see another approach to hard-covered vermin-proof crawl space insulation using rips of OSB.

A determined recycler, I took apart ducts belatedly hauled from the job, too dirty and bulky for hauling with bagged insulation trash. Recycle all metal, including spring coils chopped to about 12" lengths.  Take a pause. Send that rat ridden end above for examination by Thermaflex in South Carolina.

Thermaflex was nice, accepting a length of the brittle liner for examination at my cost, against accusation failure is general; a cause of mouse and rat access, not a symptom, surely this not the only instance. To my shock and dismay, they would disagree with me, blaming mice as cause of embrittlement. And, they offered no comment whether current production is with better material.

Sharing this blog post then with Thermaflex, I studied their product claims. Theirs are guaranteed for ten years, said to be better than with competitors .These had "served" perhaps 25 years. What are we to expect past-warranty? Have materials improved in current production? We need to know these things. 

Let's have some discussion here. What have others found? Will a manufacturer speak up about materials evolution?

I suggest to Thermaflex that I am worthy as a commenter, for teaching good flex duct installation practices. May we talk about this, too?