Hello,

You mention this dirty job of insulating the attic with cellulose requiring the need to mask and gown up. That was not the case when this program I qualified for had their contractor’s do this job. Although it took nearly all day, one very loud machine, and two men to complete, not one of them was gowned up or had a mask on. One gentleman was feeding the bags into a long and large hose, one was standing in the attic access door spraying it throughout the attic. He over filled it as now the baffles are crushed and soffits with no air flow. I wish I could post photos, an insulation company who had checked my attic (while completely gowned up) had taken photos of what he referred to as the “top plate” that was clearly left unsealed. I could see there was a small gap in it even. There are zero ducts in the attic, those all run in my basement ceiling. Although two small holes were found that lead to the attic where the crane that brought this house here in two pieces had set it down. We have since fixed these holes and sealed them up. Yet the moisture continues with a water vapor unlike any other that I have often captured with my phone on video. Not many believe me, yet my carpeting, furniture, and bedding all say this is true. Very prominent lines which appear as filtration lines along the edges of carpeting, although this is due to this vapor matter hitting the walls, then falling down and settling in those areas of which this vapor matter carries with it. The health department proved the substance to be cellulose. Although how and why remains a mystery. I’ve done enough of my own research and investigating to know most of what is occuring, but I still do not hold all of the answers. The answers I do have continue to be not taken seriously as many around here do not believe me and take me as being some sort of crazy person. A crazy person that has had more than I’d like to admit taken advantage of me as I desperately sought out help to find the answers. I recently obtained a grant that took a year to get. We were ready to pick contractors to fix the attic. Just days ago I received a phone call stating the state is now calling this “duplicate funding” and has taken this grant that took a full year to obtain, away in a matter of seconds. It is most definitely not “duplicate funding” when I was trying to fix the mistakes that were made and damages caused by that program I qualified for. Yet that doesn’t seem to matter, no one listens and no will give me a chance to be heard. Upon contacting my states Department of Administration, I was hung up on after the individual whom I do not even know, figured out it was me on the phone and told me they could do nothing for me. This has more than devastated me, I was finally headed towards putting this all behind me. Now here I sit, back at square one again. No one to help me, no one to hear me, no one to believe me. I have no where else to go, I’ve done it all these last two years. I thought I was a broken woman before, now I’m really a broken and very frustrated and tired woman and mother of two. To make matters worse, that negative air pressure which is causing all to backdraft, even my clothes dryer, has now caused my clothes dryer to finally give up. Now I must spend the rest of my day trying to obtain one from somewhere as it’s not ideal to be doing laundry for my two children and hang clothes outside in the middle of winter to dry them.

Thank you,
Michelle Castile

Rob,
I’m not sure where you’re getting your info from but this article was based on spray foaming the underside of the roof and not cellulose around the ductwork.

I agree that cellulose especially around the return ducts can cause your furnace filter to get dirtier faster! And there are always little leaks around those ducts and they can’t reasonably be sealed up without spray foaming them. Even then it’s extremely difficult depending on where they’re located.

Michelle. I am only guessing here from what others have said and being familiar with those state run insulation programs… I’m betting your return heating ducts are through the attic. You had cellulose dumped up there, as is common in these programs. It’s a nasty job- suited up and masked, its hard to see anything; on top of that, it so nasty that it’s not a far off bet that the workers were otherwise “compromised”. They inadvertently disconnected a return (or supply) duct and it is now sucking cellulose into your furnace system, blowing it through the house. If your filter is not so dirty then it is a supply duct with the hole. The Venturi effect will be sucking the insulation in or the duct is disconnected so the whole attic is pressurized and blowing the insulation back into the house. The negative pressure caused by the return being partially blocked and the furnace essentially blowing heated air into the attic. The negative pressure is also sucking moist air up from your basement which probably has a dirt floor or crawlspace that need proper sealing.
No one wants to crawl up there into the attic to investigate because it is knee deep in cellulose. Someone has to suck all of that insulation back out and fix the duct work- not as hard as it sounds (use an insulation blower in reverse). If you haven’t already, put Carbon monoxide detectors throughout the house immediately -that negative pressure can be deadly.

Armin,

I think you’re right. The whole roof radiated to the night sky, but the eaves were warmed from below by the ambient air, while the main roof was too well insulated to be warmed from below.

Scott: There’s no need for venting in a conditioned attic. You do need to control humidity here in my mixed-humid climate, though, and you can see how I do that in this article.

There’s nothing to melt on the eaves because condensation never formed there. See the comment by Armin Rudd.

The roof deck is 1×6 lumber, not plywood, in this 1961 house. If there’s any sagging, it’s practically undetectable.

Yes, thermal bridging does still exist, but my hypothesis is that thermal mass is the dominant effect.

I had the same question. My thought is that the eaves are not insulated at all. Therefore any heat that leaks upward from the heated house below is able to keep the eaves warm enough to not frost over, unlike the insulated roof portion over the attic which remains cool and tracks more closely the outdoor temp. Another possible explanation might be that if there is little air flow in the eaves portion, that similar to the main section of the roof, heat is stored in the eaves framing and air space throughout the day, enough to prevent frost, just like the rafter pattern of the article.

As for the thermal mass/transfer. Yeah, there’s thermal mass there, where the hell does the attic ventilate to since the spray foam insulation has been put in? Probably why the eves are melting due to the soffit being the best location for the heat to exit.

Another culprit that can cause this ghosting is the simple fact the roofing decking (plywood) slightly sags inbetween the framing. You can put H-clips in the wood to lessen the sagging of the wood… but there are probably tiny valleys created between rafters as well. So the framing is the highest point on the roof, and the 16-24 inches in between slightly sags lower.

Thermal bridging and mass still occurs, but there are probably other reasons as well, as generally things are many things and not one.

Jason: Yes, when you insulate beneath the roof deck, the shingles do stay hotter. But not much. See the article below. But the real issue is that it’s not temperature that kills shingles. It’s the ultraviolet radiation.

How Hot Is Your Roof? – Insulated Rooflines and Shingle Temperature