One of the first jobs I had when I started my career in the construction industry, back when I was working as an electrician, was installing electric resistance heating cables for a basement heating system. It took two people, one person pulled (me) while a second person pushed (my brother) and guided a small manual plow which installed electric heat cabling just under the surface of a sand layer. Concrete would then be poured over the sand; the result would be a heated floor. As it turned out, there was a high percentage of cable failures with this system, which resulted in many people having to install a new heating system.
This post originally appeared on the Green Building Advisor website. www.greenbuildingadvisor.com
I once heard Dr. Joseph Lstiburek use the term “pookie”, which made me chuckle. He was referring to a fluid type product used to seal something. In construction, we use a lot of different caulks, sealants, and adhesives, all of which are available in some sort of tube or bucket. A walk through the caulking isle at any hardware store or lumber yard can make your head spin, what to use when and where.
Thermal imaging has numerous uses and benefits many different trades. Everything from surveillance and industrial maintenance to checking someone’s temperature. For this post, I’ll discuss interpreting images in the residential construction field.
It’s important to have at least a basic understanding of how the camera works and adjustments that can be made to the different camera settings, I’ll briefly discuss a few of the settings. It’s also helpful that you have somewhat of an expectation when viewing a thermal image. Outside environmental conditions can affect an image taken inside a building, the conditions typically present in a predictable way, but not always. Sometimes something unexpected shows up, usually this requires more investigation, possibly confirmed using other diagnostic tools or may even require the disassembling of a building component.
2012 was the first year the International Energy Conservation Code required residential construction to pass an air leakage rate test, better known as a blower door test. My area of the country requires the test to be at or below 3 air changes per hour at the test pressure of 50 pascals (ACH50). (Other areas, typically warmer climates require 5 ACH50.) Most new construction in my market has no problem passing the test, but I have had a handful of houses fail, usually the failed tests are by a builder having their first blower door test or the project is a very small home.
Late summer, 2021, Aron Jones (bigdogconstruction.gm on Instagram) and Gina Hoyt (bigdoglifex3 on Instagram) started the International Flashing Awareness Day to bring awareness to the importance of correct flashing details. I participated by posting a failed assembly that was lacking correct flashing on my Instagram account.
This year the International Flashing Awareness Day is on Friday, August 26, 2022. Instead of producing a quick post for Instagram, I decided instead to write a blog covering the subject of flashing in construction.
The chemical decomposition of wood by the application of heat alone in the absence of oxygen.
I used to perform risk assessment inspections for a couple small, local mutual insurance companies. These companies would insure properties that were considered “high risk”, most were rural, some were accessible only by boat, ATV or snowmobile and they were often a long way from the nearest fire department. Many had solid fuel burning appliances, usually a woodstove or fireplace. Part of my job was to make sure that the woodstove or fireplace had the proper clearances to combustibles, proper floor protection, and that the stovepipe and chimney systems met the requirements of the manufacturer and/or code. Most installations were safe, but every once in a while, I would find a home in danger of burning down. Continue reading “Building Science-Pyrolysis”
This article first appeared in the July/August 2022 issue of the Journal of Light Construction. www.jlconline.com. Strangely enough, they chose to put me on the cover.
A blower door is designed to measure the volume of air moving across the blower door fan at a specific pressure difference between inside and outside the home. The volume of air measurement in the US is cubic feet per minute (CFM) and the pressure differential is measured in Pascals (50 Pascals is the standard for residential construction). One of the more common metrics used to express air leakage in a home is air changes per hour (ACH). The only way we can calculate that metric is by measuring a home’s volume.
Thermal imaging is a wonderful tool that not too many years ago, was rarely used because of the high cost and complexity of the equipment. Not the case anymore. It’s still possible to spend tens of thousands of dollars on a high-end camera, but you can buy a decent unit for under $1000. I own a very good camera I use all the time that retails for $600. This blog post will cover the different cameras on the market and the terminology and other basic information needed to effectively use one.
I’m a fan of mineral wool insulation, specifically the Rockwool brand. Over the next few months, I’ll be writing a series of blog posts discussing tips, tricks and the tools used to work with this insulation made from rocks and steel slag a byproduct of the steel industry. Before we get into those topics, I want to discuss the Rockwool products I use, the building science behind the how these products work in a wall and the characteristics of the insulation, all of which can create a well-built wall assembly.
One of the most popular foundation systems used in my market, and one I’ve been using for more than a decade, is the frost protected shallow foundation. My very cold climate requires footing depths of five feet. Digging, constructing and insulating a footing and foundation system that deep is time consuming and expensive. A shallow foundation system can be a substantial savings for a new build.