Comments on: Fiberglass Is Still the Number One Insulation for Home Builders

By: Patrick

Patrick — Sun, 18 Oct 2020 07:08:06 +0000

Good article and explanation
Good article and explanation of why the myths are really myths. I remember back in the day also being under the assumption that you would not want too much compression in fiberglass. It is all about the gaps and the R-value!

By: Rick Bayless, A Healthier Home

Rick Bayless, A Healthier Home — Mon, 22 Jul 2019 13:08:59 +0000

The mentioning about resents
The mentioning about resents is just an example to illustrate another important aspect of sustainability. Now that folks are occupying and using the completed Sustainable building, the time to manage the "what happens next" part of it becomes of critical importance. You can't stop a green bananna from turning brown, and , long term, you can't stop a green building from going brown either. We're just asking Nature to slow down the building decay process a bit until we've decided we're totally finished with it. Our maintenance plans should be just as broad-focused and detailed as our Sustainable building planning and construction process was. Otherwise building performance will fall apart sooner rather than later.

By: Brian

Brian — Mon, 22 Jul 2019 02:48:06 +0000

In reply to Rick Bayless, A Healthier Home. Rick, You are the first
Rick, You are the first person I've read to comment about rodents ,ever, besides me. I've never opened a wall without finding some evidence of them. I believe that fiberglass is their favorite material, and I've found stud bays that had no fiberglass even left after they had stripped it for nest building. They are just as much of a problem in motor vehicles. A buddy of mine had to replace his truck transmission after rodents packed it with debris. I have endless stories. But builders don't pay any mind. Their minds are filled with the details of intricate building plans and systems which they must obsessively watch for quality. Yet this perfection goes right out the window if the details do not include very robust protection against rodent invasion. Rodents work for daily survival. They don't live long, so they work fast and leave lots of offspring to inherit and expand their efforts. And it was Scottish poet Robert Burns who wrote (in translation) "the best laid plans of mice and men off-times go astray." I would say that mice don't plan much, they act on instinct. It's humans who have the grand designs, and forget about mice.

By: David Butler

David Butler — Fri, 12 Jul 2019 07:14:53 +0000

@Allison, I’m surprised you
@Allison, I’m surprised you didn’t differentiate between batts and blown-in fiberglass for walls. In my experience, it’s a lot easier to get to Grade 1 with blown-in. In fact, I can probably count on my fingers the number of true Grade 1 installations I’ve seen with batts. Yes it can be done, but good luck finding a crew that can do it.

Blown-in (typically done with netting) costs a bit more, but you can get to R-23 in a 2×6 wall, which you can’t do with batts.

By: Rick Evans

Rick Evans — Wed, 10 Jul 2019 10:51:25 +0000

Thomas,
Thomas,
That doesn’t mean you can’t have both a tight house and use fiberglass. I have dense pack fiberglass in my walls but my house came in around .2 ACH @50 Pascals.

The only cavity insulation that acts as both an air barrier and insulation is spray foam. I’d take dense pack fiberglass over spray foam every time for new construction (except for raised floors and vaulted ceilings perhaps).

By: Tim

Tim — Wed, 10 Jul 2019 02:29:23 +0000

Thomas, I think you should
Thomas, I think you should distinguish between convection and air infiltration/exfiltration. If I'm not mistaken, the later happens due to pressure differences, but the former does not, at least not significant differences. Fiberglass can't stop air moving under pressure, but does a good job of stopping convection.

By: Thomas Dugan

Thomas Dugan — Tue, 09 Jul 2019 20:46:04 +0000

Good read. The key point made
Good read. The key point made is that fiberglass insulation does not stop air flow. It is for conduction not convection. A tighter house with poor insulation is still better than a lot of insulation but air leaks. Convection always over-rides conduction every time. The homes that I build get blower door tests of .36 ACH50 consistently.

By: Rick Bayless, A Healthier Home

Rick Bayless, A Healthier Home — Tue, 09 Jul 2019 18:21:05 +0000

What happens next? Foam,
What happens next? Foam, cellulose, or fiberglass…attics, walls, or crawl spaces…rodents happen next! Their job is to explore. Despite the insulation industry’s fix of the convective looping issue, rodents make a labyrinth of thumb-sized to wrist-sized trails and tunnels (air passageways) throughout any type of insulation. Actually, it’s kind of cute seeing how the little critters have busily swept their tunnels clear of mouse-mouthful-sized bits of expanding foam onto the crawl space floor. However, what impact is that having on insulation performance? Even more important…what is the impact on occupant health with their deposits of (smelly) urine, feces, hair, nesting material, and…(sadly)…dead mouse bodies. Even more important yet… every so often in the rodent community a wire-chewer comes along. Now we have exposed electrical wiring going undiscovered. The takeaway… after project completion, immediately begin the regimen of house monitor/maintenance. After all, its been said that “Mice often make astray the best laid plans of men and women.” …or something like that.

By: Armando Cobo

Armando Cobo — Tue, 09 Jul 2019 18:16:02 +0000

I'm one of those few that
I'm one of those few that believes that all conditioned spaces above garages need to be insulated with 2" ccSF applied under the floor decking, and the remainder, with blown insulation. The reason is to stop any moisture and chemicals moving from the garage to the habitable space.

By: RoyC

RoyC — Tue, 09 Jul 2019 16:37:18 +0000

When I used to work in home
When I used to work in home construction, I always dreaded installing fiberglass batts. I would itch for a week afterwards. We always used unfaced batts. I wondered why paper-faced and foil-faced fiberglass even existed. My conclusion was so that installers could avoid touching the fiberglass, which is why it rarely gets installed properly. But why foil-faced? Is that supposed to be a radiant barrier? A vapor barrier? I don't thinks so.