Energy Vanguard Blog

Humidity in a Spray Foam Attic

Posted by Allison Bailes on Wed, Oct 5, 2016

Spray foam insulation can solve problems that other insulation materials can't. One of those problems is moving the building enclosure from the drywall ceiling of a home to the roofline. By doing so, you bring the attic inside the building enclosure. But what happens to that attic space when you move it inside? Dr. Joe Lstiburek has been saying for a while now that we can't just ignore the space. He says we shouldn't be calling it a sealed attic or encapsulated attic or unvented attic. We should be calling it a conditioned attic. Here are some data to show why that's true, at least in a humid climate.

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Tags: insulation, spray foam, indoor air quality, moisture problems

3 Reasons to Remove Attic Floor Insulation in a Spray Foam Attic

Posted by Allison Bailes on Tue, Aug 9, 2016

I get asked a lot of questions about spray foam. Do I need an ignition barrier? Should I use open cell or closed cell spray foam? Will open cell spray foam really rot my roof? But the question I get more than any other on this topic is about whether or not the insulation on the attic floor should be removed when insulating the roof deck in an existing home. As you can tell from the title of this article, my answer is to remove it. Here are my three reasons, in increasing order of importance.

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Tags: insulation, air leakage, indoor air quality

How to Fix a Leaky, Underinsulated Exterior Wall

Posted by Allison Bailes on Mon, May 23, 2016

When I began remodeling my master bathroom last month, I found the exterior wall ripe for some serious improvement. It had a number of problems, and I was excited to find them. It was worse than I imagined in some ways. The photo below shows the wall partially opened up.

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Tags: insulation, air leakage, moisture problems

4 Types of R-Value

Posted by Allison Bailes on Fri, Apr 29, 2016

We talk about R-value all the time. "I've got an R-19 wall," or "Code requires R-38 in my ceiling." But what are those numbers? As it turns out, when we talk about R-value we usually give the R-value of the insulation. That's the case with both of those statements above. But what's the real R-value of the wall or the ceiling? Insulation makes up only a part of each. There's also wood and drywall and sheathing and cladding and...

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Tags: insulation, heating & cooling

Foam Insulation and Global Warming, Part 3

Posted by Allison Bailes on Wed, Apr 20, 2016

Well, I really stirred things up with my last article on insulation and global warming. My intention was to explain why Alex Wilson's results could be doing a disservice to the green building community. In the end, I was rightly accused of have done a disservice myself. So, here goes with part three of my take on the global warming impact of insulation. Let's see if I can get closer to the truth this time.

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Tags: insulation, environment & sustainability

A Vivid Demonstration of the Benefit of Exterior Insulation

Posted by Allison Bailes on Mon, Apr 4, 2016

A couple of weeks ago I caught up with Anthony Cox at the Air Barrier Association conference in Baltimore. You may know Anthony as the inventor of the House of Pressure, a great model for demonstrating backdrafting, zonal pressure differences, and other building pressure phenomena. Well, now he's got a new toy and he brought it to Baltimore for the conference.

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Tags: insulation, moisture problems

Foam Insulation, Global Warming Potential, and BS

Posted by Allison Bailes on Tue, Mar 8, 2016

I've been reading a lot of BS lately. No, I'm not talking about blood sugar. It's brain science that's captured my attention. Understanding how the human brain works, why we do the things we do, and what common illusions often lead us astray. What I want to talk to you about today, though, is foam insulation and global warming, but first, we have to talk about calamari.

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Tags: insulation, spray foam, environment & sustainability

How to Get the Best Possible New Tract Home

Posted by Allison Bailes on Mon, Feb 15, 2016

Let's say you've bought a lot in a new development and are having a tract home built. You want the home to be as energy efficient, comfortable, and green as possible. Your builder offers only a few options, like high-efficiency heating and air conditioning systems, but you want more. That's the question I got from Kerry in North Carolina. Let's see what you can do to get the best possible result.

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Tags: insulation, crawl space, air leakage, attic, indoor air quality, health & safety

An Old Home in New Orleans Gets New Sheathing

Posted by Allison Bailes on Fri, Feb 5, 2016

New Orleans is the home of jazz, Mardi Gras, and rot. I grew up about 70 miles southwest of NOLA so I know a little something about the rain and the swamps and the muggy air. It makes it tough on buildings because the moisture comes from so many directions, but it is possible to control moisture there. Here's what we recommended for this hundred year old home that had its share of moisture problems.

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Tags: insulation, moisture problems

A Tale of Two Roofs - Frost, Snow, and Attic Heat Loss

Posted by Allison Bailes on Wed, Jan 27, 2016

It was the best of times, it was the worst of times, it was the season of cold, it was the season of heat, it was the ignorance of what was right in front of us, it was the opening of our eyes, we had warmth in our homes, we had warmth in our attics — in short, the period was so like the present period that indeed it is the present period, noisy authorities and superlative degrees of comparison aside.

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Tags: insulation, air leakage, attic, heating & cooling