Category Archives: Fiberglass Batt

And, Ladies and Gentlemen, Here Comes The Sales Pitch ….

thermal metic headerSince 2007,  all of the large insulation manufacturers and trade associations have been funding research of the Thermal Metric Project.  This project was conducted by Building Science Corporation, a respected source of independence and factually based information about energy efficiency in homes and other buildings.Batt side

The project testing Spray Foam, Fiberglass, rigid foam and cellulose. It studied batts and blown in fiberglass. You can find their final report, issued in June, 2015 on their website.  There are a lot of detailed measurements, graphs and data in the report. It is a good report that will serve well over the years.  The headlines are now beginning to show up in various social media. These are taken from the Executive Summary of the Report. When you see these in literature or social media of either insulation manufacturers trade associations, or contractors —  take the presentation with a couple of grains of salt.

So which ones will be spun for public consumption and what can one do to avoid a sales pitch. Let’s look at the main conclusions.

  • When walls are constructed with the same installed R-value in the stud space, and are air sealed, both inside and outside (i.e. there is effectively zero air leakage through the assembly), they exhibit essentially the same thermal performance regardless of the type of insulation materials used.
  • All of the tested wall assemblies were subject to thermal bridging regardless of the they of insulation material used in the stud space. Thermal bridging through the framing resulted in roughly 15% decrease in thermal performance.

There are seven more bullet points in the Executive Summary that get more technical then most builders and almost all home buyers want to know. For those that do, it is another blog post or reading the report themselves.tweet1

Here is the Tweet that I saw this morning and thought it was worth a Blog Post.

Notice the comparison is Cost.  Does this cost include the cost of proper installation and air sealing?  I have no idea. Following the links back to the website, I did find a cost of $4,000 for the batt type insulation.  Nothing about the size of the home or other details to make a reasonable comparison.

There is also no indication that batts are rarely installed according to manufacturer’s directions.  In the picture at the beginning, the batt is not installed according to the manufacturer’s instructions. In this area Dry Wall installers, will not warranty their workmanship if batts are installed according to manufacturer’s directions.

15aI included the Project’s second bullet point about Thermal Bridging.  Too many times, we hear references to an R-13 wall or R-19 wall.  This only refers to the space between the studs, not the wall.  Thermal Bridging represents the decreased value of insulation because there is wood in the wall.  Wood is R-1 per inch.  So each stud is 1 1/2 inches of R3.5 in a 2×4 wall.  This is the 15% decrease in performance.

The 15 percent also uses the recommendations from NAHB from their 1977 research on Optimum Value Framing. The National Association of Home Builders conducted this research to find ways to remove expensive wood studs almost 40 years ago.  Wood Studs are more expensive now, and still increasing. This IR image shows batts not installed according to manufacturer’s instructions (The Dark Blue Areas). It also shows the wood framing as a thermal bypass, mostly green with some blue on the top plates.

In the end, for the home buyer, a way to sort through all the sales pitch exists. For new homes of half of the new construction in 2013 was verified independently by a HERS Rater.  I do this in the Wichita metro area for builders and new home buyers.

Previous Blogs of Interest:

Installing Fiberglass Batts

Insulation in Your Walls

 

 

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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Shivering And Bowl Turning are not Compatible!

When I am not out auditing homes, or working with builders on Energy Star New Homes, I enjoy Woodturning! Making a bowl or other turned object is fascinating; it takes my mind from serious things and to important things. It lowers my blood pressure!

I have been using my garage to work with my lathe and the wood! It keeps my head from getting sunburned, and keeps the sun and weather off the wood waiting to be turned.  My. attached garage is 57 years old. The common wall between the garage had unsealed drywall on the garage side!  The exterior walls are open studs. The house is old enough the wall and  roof sheathing is 1x material. You could see the boards that were used to form the basement walls.  That is one form of recycling!

The use of 1x material, despite the recycling, is not the most green approach that could have been used. The garage has not really been usable in the cold, so 4-5 months are lost. I have tried various types of heating to allow work to proceed. It works with warmer, less windy days. This is Kansas and there aren’t many of those!

One of the personal goals involved in my becoming an energy auditor was to learn how to make my shop workable 12 months a year. My study of insulation types, heat loss, installation methods and costs, all applied to my quest!

I looked at installing Fiberglass Batts, inexpensive.  I thought about adding rigid foam, also inexpensive. I could do the labor on each of these.  Each of those would require a covering, at least for physical protection of the insulation, and ignition protection of the rigid foam. The same problem, of a protective covering would apply to blown in rock wool, fiberglass or cellulose. And yes, I could do those or contract them out.

Each of these choices must also have the insulation in contact with the Air Barrier, to work at the rated R-Value. In our climate zone, the air barrier is the lath and plaster, or drywall.

The other option, slightly more expensive than the others is commercial 2 part Closed Cell Spray Foam.  This product at 1 inch thickness provides an air barrier. The manufacturer’s material shows R-6.5 per inch.  So 2 ½ inches is about R-15.  And the air barrier and the thermal barrier are in contact thus forming a valid thermal envelope.  The underside of the roof deck and the walls could be done.  The actual time to install would be less than one working day.

So one March 1, the Foam Installer was here and sprayed the foam.  Following the weather in March we had several days the low temperature was in the 30s, with highs in the 50’s or 60’s.  By April the lows moved into the high 40s and 50s.

Now it is July and we have had highs in the triple digits or close for about three weeks.  Lows in the 70’s, a few 80s and high 60s.

How is the insulation performing?

The temperature in March never dropped below 50 degrees, even on the days with a low of 35.  One night I left a window open and the low of 40 did not drop the temperature below 55 after a 65 degree high.  That seems very satisfactory to me.

Since our high temperatures hit the 90s and then into the triple digits, I have observed a 5 – 10 degree delay in the temperature inside the garage.  I don’t have any AC there.  So a 103 degree day like today, the temperature in the Garage was 93.

I have two fans to create air movement.  One is a squirrel cage fan I purchased at a garage sale.  The other is a box fan.  I also can turn on the air cleaner hanging from the ceiling and it will move air around the garage. Use of the fans with doors and windows providing a source of air movement have made those triple digit days seem much more like 80 in the shop.

My choice to insulate my garage for use as a shop was not simply based on this type or that type of insulation.  It was based on how the wall would work with an air barrier and a thermal barrier in contact.

I could have used: Fiberglass, Rockwool or Cellulose with drywall covering. The time involved with any of these would work using a contractor or doing it myself and would have taken several days to a week.  Going the Closed Cell Spray Foam approach took less than a day, and I was done.

When winter comes, as it always does, I will watch and comment again. The old furnace is now installed in the attic of the garage to kick on if the temperature drops below 40 degrees.

One goal is to have a shop that is warm enough to work in all year round. Another is to keep the shop equipment above Dew Point.  That is the temperature when the humidity begins to condense on cold objects. In the summer we think of our cold beverages sweating .  Today the Dew Point was 59 degrees and any cold beverage, including tap water is colder than that. If the temperature of the equipment goes below dew point, the condensation will cause rust.

Rust on the shiny steel of the saws or the lathe is not good. So here is to keeping the shop above the dew point, and your cold beverage below dew point.

Cheers!

The Foundation of your Home: Slabs, Basements, and Crawl Spaces

What is under your home?  I hope you have some solid ground.  If you do great!  Now how did your home builder get to solid ground?

The first of a multi-part topic.
Left: Slab on Grade ready for walls. (courtesy of Wikimedia Commons)

That can be done with a slab on grade construction. It can be done with a basement.  It can be done with a crawl space. A home can use a combination of methods. It is not at all uncommon to see homes with 3 of the 3 approaches.

Above Right: A slab on Grade shows heat loss through the slab. This is under the front door. Inside temperature is 72 degrees, outside is 14 degrees. The cold (blue) pile is snow.

Basements are generally a below ground space that contain living area and is capable of being heated.  This does not include below ground spaces that are for storage or storm shelter. Basements may be full, view out, or walk out types.

Left: Typical craw space, showing rim joist. This has about 30 inches of concrete and a 2×8 floor joist.

Crawl Spaces are below ground space with no living area.  They are generally low head room spaces, hence the name – Crawl Space.  Some you can actually walk in.  I have seen several crawl spaces that are only 12 – 15 inches high, most are 30 – 48 inches high.  Crawl spaces generally have duct work for the HVAC system, plumbing, and wiring. Occasionally the furnace will be in the crawl space.

Below Right: This addition has 2×10 floor joists with support beams. It provides about 8 inches of clearance between the floor and the beam.

Many homes have a basement with crawl space. Builders in one geographical area tend to build with the same approach.  Another geographic area will find another approach being common. In places where the water table is only a few feet below ground you would be hard pressed to find a basement.  In places with large rock formations near the surface, the builder could use any of these approaches depending on how deep the rock is on the building site.  In tornado alley, basements are always welcome for a storm shelter, and some families use their crawl space.

How do these spaces impact the energy use in your home?

Depending on the age of the home, the below ground walls of the house could be of stone, block, rubble fill or concrete.  These are hard materials that have similar physical properties.  They have high thermal capacity; they will stand extended periods below ground in contact with dirt and moisture.

Thermal Capacitance

Thermal Capacitance is the physical characteristic of a material to hold heat. How long does an object stay hot after being heated? The longer is retains heat, means a higher thermal capacitance.

Above Right: The Rim Joist is where the basement window is. Note the heat transfer through this area. It is somewhat diffused by the brick veneer. Outside temperature is 20 degrees, inside temperature is 68 degrees about 10 pm.

Growing up in Southern Nevada, I lived in a house constructed of concrete blocks.  My bedroom was on the east side.  An 8 foot fence stood 4 feet from my bedroom wall. The sun did not shine directly on my bedroom wall until about 11:00 AM and by 1:00 PM it had passed over. I would go to bed at between 10:00 PM or 11:00 PM and the wall would still be well over 100 degrees. So that wall loaded enough heat during that 2 hour period, to still be over 100 degrees 9 hours later. If a material can hold heat like that, then it can also hold the absence of heat, or cold, in the same way. Concrete, and stone have a high thermal capacitance.

Any basement or crawl space wall will extend both above and below ground. It is not uncommon to see a wall 1 and ½ feet above ground and the rest below ground.  If that portion of the wall is un-insulated, the heat will flow through the wall. Heat will flow in during the summer and out during the winter.

The Infrared Image (Above Left) shows a concrete basement wall. The upper part is showing relatively cooler and the bottom relatively warmer. The mid-point of this image is about 4 feet below the top of the concrete wall. The outside temperature is 45 degrees. Imagine the difference at 20 degrees?

What can the homeowner or the builder do to these walls for energy savings?

Insulation is the obvious answer. What kind of insulation is a better question. I would specify the insulation, you choose, to be installed correctly, that it be durable and properly protected from damage.

Before we actually get the insulation, we need to make a stop.  Air movement through and around the insulation will significantly impair the effectiveness of the insulation.  So lets tighten up the area.  The first area to look at is the Rim Joist.

This is on the Rim of the foundation wall. The floor joists, 2×6 or larger or a truss system rests on the top of wall. If you look at any of your rim joist area you will see a number of things.

(Right) An IR image of a Rim Joist. Outside temperature is 70 degrees. This is a south wall and the sun has been shining on it. Lots of solar loading.

Usually your outside faucets come through here. The gas line enters the house at this point, the air conditioning copper tubing, and perhaps other utilities.  I’ve seen dryer vents installed here, and even the flues of conventional hot water heaters.  Those are usually easy to spot because the flue then goes up the side of the house above the roof.  If you have a tankless hot water heater, the PVC flue may well exit the area through the rim joist.  Then you have joints, knot holes and it is not uncommon to see actual holes where something was there and has been removed. All these holes and gaps need to be sealed up.

Remember that insulation does not stop air movement. Caulk is great for stopping air leaks.  You can use caulk straight from the caulking gun.  Some gaps, may need  backer caulk also called rope caulk.  This is ½ inch strands of caulk like material that you can push in by hand. Then come back over it with the caulking gun.  Smooth the caulk with a tool, or your finger to make it go a little farther, make it look a little better and to eliminate any bubbles that might have formed.

If the gap is larger you may wish to use some of the foam in a can. This one part expanding foam uses moisture to cure. Use along a rim joist would probably have enough moisture to cure properly. Take seriously the caution, to not wash with water if you get in on your hands or elsewhere.  Water will cure it.  It will take a couple of weeks to wear off.  If you don’t ask how I know that, I will not turn red in the face!

You can also use rigid foam on larger openings.  Just remember to caulk the edges.  Also remember to caulk the joint between the sill plate and the concrete. New builders use a gasket now,  a bead of caulk is always helpful.

If the rim joist has insulation, you can remove it to do the air sealing.  You can replace it after air sealing, just be sure to install it properly. It is most likely a fiberglass batt, it may have a paper backing on it, it may not.  The paper backing may be facing the inside or the outside. I’ve observed all these in the same house.  The paper backing is a vapor retarder. It should face the warm in winter side of the wall in this area of Kansas.  (Climate Zone 4)  The batt insulation should fill the space between the floor joists, the concrete rim and the subfloor. That space is probably 8 inches deep, 16 – 24 inches wide and 6 ½ to  24 inches high.  Most common would be 8x16x 7.5 inches.

Since the Rim of the foundation wall is usually 8 inches wide, that would allow, at R-3 per inch, insulation of R-24.  I see R-19 batts commonly used here, older insulation jobs or homeowner installed jobs will show R-13, or even R-11.   If you have a ceiling in your basement, you may only have access to part of this area.  You can work in the accessible area and make a difference.

To remove a finished ceiling and then replace after the air sealing and insulation is completing will probably not be cost effective, even if you do not consider the effort of the Do It Yourself labor.

This is the first of a multi-part topic. We will look at Basements, both finished and unfinished, crawl spaces, and slab floors each in more detail.

Insulation: Properly Installing Fiberglass Batts

The last two posts have concerned issues of properly installing Fiberglass Batt type insulation.  That discussion revolved around newly installed insulation.  Inspections were done after the insulation was there and before the drywall was installed.

In this post, I would like to address some of the problems I see after the home has been in use.  The Batts in these cases were installed anywhere from 10 years ago to 40 years ago.  We all have experienced the issues of time. What changes does time bring to a Fiberglass batt?  This leads to ‘Why proper installation is so important.”

I have audited home that were built more than 100 years ago.  My friend Bud, has discussed auditing homes that are much older, 150 – 250 years. A home lasts a long time.  Every month the home gets Energy Bills.  Are the Energy Efficient Features of the home keeping those bills at the level they were planned?  If a feature was improperly installed, probably not.

Best Practices for installing Fiberglass Batt type insulation include:

The insulation must be in contact with the Air Barrier.  In our Climate Zone the Inside wall is the Air Barrier.

This means the batts must be stapled to the face of the framing material; not to the side.  If you have the batts stapled that way, then they are not in contact with the air barrier.  This is illustrated in the Infared picture. Note the cooler colors near the top that are rounded and follow the framing down the wall, and the dark hole in the top of one wall cavity.

 

Batts showing air movement, not in contact

Batts not incontact with Air Barrier

A Fiberglass Batt must be covered on each of the 6 sides.

This one seems simple, in an exterior wall, the top plate, the bottom plate, the drywall, the exterior sheathing, and the framing constitute all 6 sides of the batt.  Now think about the wall that is formed between the end of the vaulted ceiling and the attic?  OK;  Drywall, Yes!; Bottom Plate, Yes; Top Plate, not usually; Framing, sort of; exterior sheathing, usually nothing.  So, we have 2.5 on these types of walls. Below is a picture of the end of two knee walls with no framing on a corner of a vaulted ceiling.

Knee wall from Attic Side

Solutions on Knee Walls:  Cover the top, back and the sides of the batts at the corners with an encapsulating material.  House wrap installed according to manufacturers directions is a good choice for an existing home.  Easy to get into the area and then apply.

A Batt should not be compressed.

OK!  Think about all the things running in walls.  Electric wires, pipes, CAT 5 cable; phone lines, cable TV, security system cables.

Poorly installed Batt Insulation

Poorly installed Batt Insulation

First, you have the installs that are done before the insulation is installed; typically the electric and plumbing.  The insulator can deal with these easily. The batt can be sliced, partly through, to allow the obstruction to pass through the middle, instead of stuffing the batt behind or pushing the batt into place on top the wire or pipe. It can be carefully cut to allow an electrical box.

Good Installation of Fiberglass Batts

Good Installation of Fiberglass Batts

For those tradesmen that follow the insulator, everyone else on the list above, it is not quite so easy. If they come before the drywall is up, then you may find holes in the kraft paper, and wires compressing the batt as it runs from 2x to 2x; or you may find something else. If they come after the drywall, your guess is as good as mine as to what the wall will actually be.

The infrared image below shows air infiltrating around improperly installed fiberglass batts on the other side.

Infrared Image Infiltration in Knee Wall

 

If you are renovating a wall in your house, and you choose to insulate; fantastic!  It will save you money.  Lots of insulation choices available, if you choose Fiberglass Batts, follow these concepts and you will maximize the effectiveness of your insulation.

 

The only other item you should do, when renovating and insulating is to air seal and stop those cold drafts. That is a subject of another post!

Insulation: How To Do Business with Customer Service in Mind Part II

Last Sunday I wrote a post about the Lawyers being sent to my friend and fellow Building Science Blogger Allison Bailes regarding a post on his blog. http://www.efficientenergysavers.com/energysaversblog/insulation-how…ervice-in-mind/ ?

I received a copy of the letter from the President of Guardian Insulation to Allison late yesterday.  Allison provides the letter and his comments in his post today. http://bit.ly/v3uDL5

I am happy to see that Guardian Insulation can look at a situation and resolve it in terms of Good Customer Service.  Mr. Ziessler strongly indicated that Guardian would like to “engage the broader discussion with Allison and his readers about how to improve energy efficiency in homes and  the quality of installation across the spectrum of building products.”

I look forward to this join effort to improve the state of quality installs on any type of insulation.

Insulation: How To Do Business with Customer Service in Mind!

I do Home Energy Audits. When I am collecting the data from the home, I look at many things that effect energy usage. Equipment, Solar Orientation, Infiltration and the building shell (includes doors and windows), and Insulation are the major components.

I like insulation. A home with lots of insulation is like waking on a cold morning and feeling the warmth of the bed with the covers pulled up tight. Stick you pinky out or have the covers pulled and BRRR! Same with your home.

I like lots of insulation. The more the better. The only limit seems to be how many years will the current utility rates provide a payback. I try to keep my recommendations in the 10 – 20 year range. Beyond that, you can better spend your money for other improvements.

What insulation is best? All of them! I have yet to meet a bad type of insulation. All forms have their advantages and disadvantages. Some work better in one place, others in another place. Some work well in several places.

What differentiates the different types of insulation?
The color of the insulation?
NO!
The Manufacturer!
Probably not!
The installer hired to put your insulation in place!
Yes!!!! You’ve got it.

A good installer will install the insulation correctly! That means according to the specifications of the manufacturer and Industry Best Practices. Manufacturers specifications can be found on the Manufacturers website. Industry Best Practice can be found at Energy Star; Dept of Energy; and the Building Science Corporation.

When looking at different types of installed insulation – which is the one I see most often installed incorrectly? Fiberglass Batts!

Poorly installed Batt Insulation

Poorly installed Batt Insulation

This image shows an example. Compressed, miscut, uneven, stapled to the side of the 2x not the face.

Why are these problems not either following the Manufacturer’s Recommendations or Industry Best Practices? To maximize its effectiveness, Fiberglass batts need to be installed with no compression. The insulating value is their air pockets between the strands of fiberglass. Anything that results in compression degrades the performance of the installed insulation. In many cases badly installed insulation is no better than no insulation.

Good Installation of Fiberglass Batts

This image shows fiberglass batts installed correctly. The batt is cut around the electrical box, the wires do not compress the insulation, it is stapled to the face of the 2x and it is cut to the correct length.

So, what are the white spots in the photos? I took the brand name out. Why? My friend and fellow HERs Rater, Allison Bailes of Energy Vanguard recently received a letter from the lawyers for Guardian Insulation complaining that his blog post, similar to this one, defamed their product and their company! Why, because he left the name of the company on the picture of the batt that was installed in error of the manufacturer’s specifications.

    Why is the first reaction of some people to ‘call the lawyer’?
    Is that good business?
    Is that good for business?

I don’t know! No! No!

What could Guardian have done differently?

They could have supported their own manufacturers recommendations and worked to educate the installer to do a better job next time.

They could have a responsive technical assistance department to assist those installers and others who ‘want to get it right the first time’! Other manufacturers of Fiberglass Batts have these people – and they work well with those who ‘want to get it right the first time’!

Will Guardian continue with the lawyer track or move to a customer service track? Only time will tell.

For more information on the letter from Guardian and the story of batt insulation installed incorrectly you can go to Allison’s Energy Vanguard Blog at http://bit.ly/ueocQo

or Martin Holiday’s Blog at http://bit.ly/rs7HhK