Author Jeff B

Africa

This took me by surprise.

Insulation Roundup

The BGI Insulation Report is on our server under reference/material guides. Six HSW credits! Go for it.

Keeping 4-5-10-30-60 in mind, here are the best choices by application, considering the greenness of the material only. In practice, moisture dynamics, air leakage, condensation, and assembly mechanics might make the second-best right for a particular situation, but most of the time it’s easy to stick with number one.

Best
Choice
Approximate
R-Value
Environmental
Notes
Performance
and Cost Notes
Cavity Fill, Residential
Dense-packed cellulose3.8Low embodied energy.
High recycled content.
Renewable.
Impedes air leakage.
Allow to dry to at least one side.
Cavity Fill, Commercial
Spray-applied or dense-packed fiberglass4.030% recycled content.
Higher embodied energy than cellulose.
Fire-resistant.
Impedes air leakage.
Note susceptible to moisture.
Acrylic binder allows installation without netting.
Insulating Sheathing, Exterior
High-density rigid mineral wool.3.0High recycled content.
Excellent sound control.
Insect- and moisture-resistant.
Faced and unfaced.
Tricky detailing for many types of siding.
Insulating Sheathing, Interior
Foil-faced polyisocyanurate.6.3GWP blowing agents have been eliminated.Highest R-value of common materials.
Affordable.
Radiant barrier.
Impermeable if foil-faced.
Foundation Wall, Exterior
Cellular Glass3.0High compressive strength.
No blowing agents or flame retardants.
Expensive.
High-density rigid mineral wool3.0Hydrophobic.Harder to install and cover.
Foundation Wall, Interior
Polyisocyanurate6.2High embodied energy but GWP blowing agents have been eliminated.Good for flat substrates.
Sub-slab Rigid Insulation
Cellular Glass3.0High compressive strength.
No blowing agents or flame retardants.
Expensive.
EPS Type II or Type IX4.2Manufacturing pollution issues.
HBCD flame retardant.
Use higher-density types.
Attic Floor Insulation
Loose-fill cellulose3.6Low embodied energy and carbon.
Renewable.
High recyled content.
Vapor-permeable but impedes airflow.

Recommended (not Code) Insulation Values?

For moderate climates, the recommendation is: 4-5-10-30-60.

That is: R-4 windows, R-5 under slabs, R-10 foundation walls or slab perimeter, R-30 above-grade walls, and R-60 in the attic or roof.

Condensation Roundup


Give Mr. Water and inch and he sneaks in to take a mile. The Cloak of Vapor Invisibility is one of his best disguises.

Here’s a little quiz:

Do you know our climate zone?

Do you know the thickness of rigid insulation required by code on the outside of wall sheathing?

Do you know the required thickness of rigid insulation above the roof sheathing, for unvented cathedral ceiling assemblies with vapor-permeable insulation below the sheathing?

Do you know where the vapor barrier should be placed in a wall in our climate?*

Did you know that the best insulation comes in a board version that is rigid enough to screw 1×3 furring strips through without deflection?

Do you know the correct techniques for specifying and installing dense-pack cellulose insulation in walls and ceilings?

Do you know where to get ROXUL mineral-wool insulation locally?

We use walls to climate-control an interior, and also, weirdly, for the distribution of pipes and wires. Do you know that one of the best ways to vapor-seal your residential wall assembly also sorts out the pipes and wires from the insulation, thereby improving effectiveness of both?

Do you have good ideas about how to get a vapor-seal to span the band board required by standard western platform framing, when a vapor-seal is indicated by the building’s climate zone?

What does your thermal barrier checklist look like? Here is the one provided by the 2009 IRC.

And finally, do you understand the difference between a vapor barrier, a vapor retarder, and an air barrier? Do you know how to properly deploy them in our climate? Did you know that for tricky hot/cold climates like that found in Virginia, there is a vapor retarder with seasonal intelligence?

* ATBVO is the acronym to keep in mind for Virginia, according to our favorite energy consultant. “Air tight, but vapor open” to both sides.

Ten Steps to Becoming the Designer You Want to Be

Good advice from a self-described mentor and design veteran.

  1. Get the book
  2. Get the obscure book you’ve never heard of
  3. Choose a topic that fascinates you and learn it inside out
  4. Write, blog, and speak on that topic
  5. Learn Something New Every Day
  6. Create a New Idea Every Day
  7. Experiment
  8. Learn as many frameworks as you can
  9. Choose variety over anything else
  10. Model or draw (all the f*@#ing time)

She begins:

An open letter to the next generation of designers, part 1.

Everyone has moments in their career when they look back and think, “If I had only known then what I know now….” After 15-plus years as a designer and design researcher at places like IBM, Trilogy, M3 Design, and now frog design, I know I certainly have. Which is why, now that I’m a veteran, I’d like to give share some advice with young designers just starting out. If I could be your mentor, this is what I would tell you:

Jump to link.

Footnote:

The obscure book referenced above is The Universal Traveler: A Guide to Creativity, Problem Solving & the Process of Reaching Goals. I discovered this book as an undergraduate in architecture school and I am sure my teachers hated seeing such a hippy book in their studio. Maybe they were on to something: I found the book’s language unfathomable. I barely understood what it was about. Yet it spoke to me, and apparently some seeds were planted. So we have bd-MAP: not a Universal Traveler – as we’re trying to get a rather specific type of work done. bd-MAP would be your Specific Traveler According to Universal Themes.

Wind Infographic

Near real-time wind map, updated hourly.

Manifesto

A set of core principles as relevant today as they were in 1860. My how times don’t change:

  • Find joy in work
  • Create objects that are not only well-designed, but affordable to everyone
  • Live simply
  • Stay connected to nature
  • Maintain integrity of “place”

Link.

 

AC Tips

For St. Paddy’s day, a useful page of Irish ArchiCAD tips and tricks.

Teamwork Rollback

A quick word about rolling back to an earlier version of your work in teamwork.

I just recovered days worth of work, so I’m happy to give this feature a high grade.  Basic description below, followed by an idea of how to use this tool in a more intentional way to manage design options.

Cognitive Biases

A few hundred reasons why it is so hard to make a good decision.

Given my own textbook Optimism Bias, I just know you will read the link through to the end, then employ a process of rigorous self-assessment, so that you will avoid all such decision biases in the future.