Construction Materials-Airtight Electrical Boxes

Working as a residential electrician back in the late 1990’s, I remember learning of a new electrical box that we were asked to use on all exterior walls and in the ceilings of unconditioned attic spaces.  At the time, they were called “vapor tight” boxes.  These boxes were designed to reduce air movement through wall or ceiling cavities by sealing the electrical box to the wall or ceiling air barrier and also to seal the electrical wires where they enter the box.  Air will contain at least some water vapor, by air sealing the electrical box, we were also reducing the amount of water vapor that could potentially enter a wall or ceiling.   The name “vapor tight” was at least partially correct.

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Construction Materials-Success with Construction Tapes

This post originally appeared in the August/September 2022 issue of Fine Homebuilding Magazine.  Choosing the Right Construction Tape for the Job – Fine Homebuilding

Walk through any modern construction project and you’re bound to see construction tape somewhere on the site.  Whether it’s taping the seams of a mechanically attached water resistive barrier (WRB), flashing a window or door opening, or making sure an air barrier is continuous, tapes have become a key part of many assemblies.  Mostly, we use tapes for two purposes, to keep something in, like the air we pay to condition, or keep something out, like water.  It’s important to use the right product for the right application.

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Construction Materials-Cavity Insulation

Heat wants to move from someplace hot to someplace cold.  It’s desire to reach equilibrium is one of the principles of the second law of thermodynamics.  We have many methods and materials we use in construction to try to slow this movement.  It’s expensive to condition a space and we want to hold on that space conditioning for as long as possible.  One way we try to slow heat loss or gain is to prevent the wind from blowing through the home.  Another is to shade the sun from beating through a window on a hot, sunny day (in some climates at certain times of the year, the sun can be a blessing).  Insulation is one of the big ones we use to provide comfort to homeowners.

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Construction Materials-Sealants

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.

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Construction Materials-Tape Test-Part 3

This is the final post on this round of construction tape testing.  As you might recall, the first tape test post was about cold temperature application of the tapes, and then trying to remove the tapes off various substrates while remaining cold.  (See the first tape test post here.)  Some performed better than others, but none had the tack of the second round of testing which was performed on plywood at room temperatures.  (See that post here.)   This final round of testing came about because I still had a question.  Will the tape bond increase if the tape is applied at cold temperatures and then warmed, much like a normal construction application might experience?

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Construction Materials-A Less Common Sheathing

This post first appeared on the Green Building Advisor’s website.

When I first started working in the trades as an electrician back in the mid 1990’s, we worked for a couple contractors that liked to use buffalo board sheathing.  I suspect the product was given this name because of its resemblance to buffalo chips.  (If you don’t know what a buffalo chip is, you’ll have to look it up, it’s not the kind of chip you eat.)  I’ve heard it called several other names, bildrite, beaver board, brickboard, bagasse, but it is best known as fiberboard sheathing.

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Construction Materials-Construction Tapes-Cold Weather Testing

In 1845, a surgeon figured out if he used a little adhesive on a piece of cloth, a “bandage” could be used for wound care, the first tape was invented.  Through the 1900’s, the evolution of tapes continued.  1925 saw the development of masking tape used in painting. In the 1930’s, scotch tape was invented.  This clear tape was hugely popular and had many uses. Water resistant duct tape was invented during World War II, originally designed to seal military ammunition cases.  More recently, the tape evolution has exploded into the construction industry.

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