Common Building Science Mistakes to Avoid

This blog post first appeared in two issues of Fine HomeBuilding Magazine: Issues 321 and 322.  Part of a series that included 17 short articles written by 7 different authors.  My first contribution appeared in the letters and reader feedback section of the February/March issue, titled “The biggest mistake of all?”  You can read that post here. 

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Ice Dams-Why They Form and How to Reduce their Risk

There is a lot of confusion as to why ice dams form on roofs in cold climates.  This is understandable, some years we experience heavy ice dams, other years have little to no issues.  Changes in weather from year to year can have a major impact on their formation.  I’ve seen new homes with ice dams that are completely related to winter freeze/thaw cycles.  That being said, most ice dam issues are directly caused by certain characteristics of the home, namely insulation levels and air tightness.

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Construction Design-Problems with Attic Trusses

This post first appeared on the Green Building Advisor Website

Attic truss, also known as a room-in-attic truss are a way to create a living space without the need to add a full second story to a home.  These factory-built roof systems simplify a roof buildout and are engineered to meet the structural requirements of your local codes and conditions.  I commonly see them used for bonus rooms over garages and integrated into slab-on-grade homes to add living space without needing to add to the height of the building.

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Vapor Control in Walls with Continuous Insulation-IRC Chapter 7 vs Chapter 11

This article first appeared in the January/February 2024 issue of the Journal of Light Construction.  www.jlconline.com

The International Residential Building Code is supposed to provide clarity into how builders construct homes.  In the IRC’s own words, The IRC was created to serve as a complete, comprehensive code regulating the construction of single-family houses, two-family houses (duplexes) and buildings consisting of three or more townhouse units.”  Usually, the codes do a decent job giving us options on how we should build homes with the occupant’s safety and health as our number one priority.  Codes also address energy efficiency and building durability.  Sometimes though, codes can be quite confusing.  How we handle vapor retarders when using continuous insulation is one of those areas.

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Northern Built Pro’s Top 5 Blog Posts for 2023

Happy New Year!  2023 was a good year for the Northern Built Pro website with 45 new blog posts, many first appearing on the Green Building Advisor website, and some that ended up in a couple trade magazines, Fine HomeBuilding and Journal of Light Construction.  I wrote a few that were directly for manufacturers of building materials, including Rockwool, Andersen Windows and Doors and Sashco.  I am looking forward to partnering with a few additional manufacturers in 2024.  A teaser to one that I am currently writing an article about, TimberHP.

These are the top 5 blog posts that were written and published in 2023.

5.  The Diminishing Return of Insulation

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Code-Blower Door Testing a Small Home

This post originally appeared on the Green Building Advisor website.

Code compliant blower door testing of a small home can be very frustrating for both the person performing the test and the homeowner or contractor who are required to have the test.  A few months ago, I tested a 952 square foot, newly constructed home with a volume of 7616 cubic feet, one of the smallest I’ve tested.  The house had a leakage rate of 416 cfm which resulted in a 3.28 ACH50 number.  A failed blower door test (my climate requires 3 ACH50 or less).  If we take that same CFM rate but increase the ceiling height to 9 feet, which changes the volume to 8568 cubic feet, 2.91 ACH50, a passing test.  Either way, 416 CFM of air moving through the blower door isn’t much, some kitchen exhaust hoods can move more air than that.  Seems unfair to punish smaller homes when blower door testing, especially when the blower door test is testing the surface of a structure, not it’s volume.

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Windows-Water and Air Sealing

I’m going to make a statement that not everyone will agree with, windows leak water.  Not all are leaking now, some will develop the leak later, as the window and the sealing products used to install the window age.  The leak may be an error or failure in the installation, or it could be the window itself that is leaking.  It could be a design error, water funneling off a roof over a window, such as in the photo.  The leak may only be an incidental amount of water, or it could be a major bulk water concern.  The leak may also only be active during the once every ten-year major rain fall event.  The point is windows will leak water.

Photo by Eric Strommer-Strommer Home Improvements

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The Thermal Bridge

Thermal imaging is an awesome tool, it can be used to find areas of missing insulation and other temperature anomalies in the building shell.  It can help us find issues with electrical, plumbing and heating systems.  And when used in conjunction with a blower door, we can often “see” the air leaks.  The photo below was taken without the assistance of a blower door, I was at this new home to conduct a blower door, but the test hadn’t begun at the time this photo was taken, can you say thermal bridge!

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What is R-Value?

This is the first in a series of blogs I’ve written for Rockwool and the R-Class Builder Program.  If you are not already a member, you can join at this link, Rockwool R-Class.  The R-Class program is free.

What is R-value?  I write often about different insulations, how they perform, where they should and shouldn’t be used.  I think this blog post should go back to the basics and talk about what is R-value, how it is calculated, and how much is needed.

This concrete foundation is not insulated, concrete has a much lower resistance to heat flow (R-Value) than the insulated wall. This becomes evident when using thermal imaging. Heat is leaving this structure through the concrete. Insulation will slow this heat loss.

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Indoor Air Quality and Building Diagnostics

The post originally appeared on the Green Building Advisor website.

I recently purchased the CPS IAQ PRO SmartAir professional indoor air quality meter to use during energy audits and building diagnostics/investigations.  My intent with the purchase was two-fold, first to learn more about indoor air quality metrics by testing homes in my market, and second, to have a more accurate temperature/humidity/dew point estimation inside these homes.  I recently had the opportunity to use the tool on a building investigation, I’ll outline this case study later in this post.  First let’s talk about the features of the CPS IAQ PRO SmartAir.

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