Daily Archives: July 11, 2014

Insulation In Your Walls

Poorly installed Batt Insulation

Poorly installed Batt Insulation

I’ve been working with a local builder on his insulation.  He decided to upgrade his standard package of insulation for the walls in his homes. Most homes in this area are built on site with 2×4 walls.  Insulation is almost always installed in the cavity between the studs. The insulation most commonly chosen is a Batt Type insulation.  I’ve seen some mineral wool batts installed during construction in Wichita, most batts are Fiberglass.  They come in white, pink, yellow and a brown.  Color is from the manufacturer, think advertising.

I’ve been working with a local builder on his insulation.  He decided to upgrade his standard package of insulation for the walls in his homes. Most homes in this area are built on site with 2×4 walls.  Insulation is almost always installed in the cavity between the studs. The insulation most commonly chosen is a Batt Type insulation.  I’ve seen some mineral wool batts installed during construction in Wichita, most batts are Fiberglass.  They come in white, pink, yellow and a brown.  Color is from the manufacturer, think advertising.

The concern with a batt type insulation is how it is put in the home. Workmanship is always an issue.  Is it installed to hold the price down?  Is it installed to maximize the Energy Efficiency. There is no code in the Wichita area requiring insulation.  Until two years ago, the recommended code for our climate was R-13 for walls located above the ground. In 2012, the recommendation changed, primarily due to increasing energy costs. The change was increased to R-20. While this a large change of approach for builders that have not had to comply with a code, it is not unreasonable given the cost increases of energy, since the R-13 was set back in 1992. Batts

Here is a typical FG batt wall, from 2013.  Notice the compressed and poorly cut areas on the bottom of the right side. Not the gap along the right edge from the top to almost the bottom. Insulation is missing in places. This home had 74 square feet of missing insulation, because batts are hard to install with maximum energy efficiency in mind. How many places on this wall is the insulation not going to touch the drywall.

Batt sideThis is a shot of a wall built in 1965 with batt insulation.  Not much different from today. The installers stapled the batt to the side of the framing. You can see the gap along the side of the 2×4.  This space allows air to move inside the wall and prevents the insulation from working as intended. This can be a lack of training, supervision, knowledge or in some cases trades working against each other. Some drywall installers will not guarantee their work if the batts are face stapled.

This raises the question the builder was asking.  How do I install insulation to maximize the energy efficiency and maintain the drywall guarantee and not drastically change the costs.

The answer was a Blown In System.  Using a loose fill fibrous insulation the contractor can blow the fibers into a netting material stapled to the studs.  There are contractors that do this regularly with mineral wool, cellulose and fiberglass, the three main forms of fibrous insulation. The insulation contractor uses a Blown-In-Blanket© System.  These certified installers receive training and certification based on Professional Standards published by the High Performance Insulation Pros.  Here is their website.  BIBS Sink

This picture shows Blown-In-Blanket© System on a kitchen wall.  I chose the kitchen wall because all of the electrical and plumbing running through it  Very hard to properly install batts. Very easy to install BIBS and maximize the energy efficiency.  BIBS blown in at 1 pound per cubic foot in a 2×4 wall provides R-13 insulation. At a density of 1.8 pounds per cubic foot it provides R-15 in a 2×4 wall. These ratings have been verified using testing standards from ASTM C.665, and C.518. How does the builder know it was done right. Visual inspection helps and the contractor can weigh a cubic foot taken right out of the wall.

In my case as an Energy Rater, the HPIP Association has provided me with a Density Checking Kit to also verify compliance with their professional standards.

I leave you with two Infrared Images.  The Right is a wall with Fiberglass Batt Insulation. The Left is a wall with a BIBS installed insulation.  If the Heat Transfer Resisting properties are consistent over the entire wall, the color will be the same or close.  Take a look and decide for yourself which works better.

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