If you have ever walked into a house that is not insulated you will immediately notice that noises from outside of the house are “louder” than in an insulated home. This is because the sound transmission coefficient (STC) is lower. Read about STC ratings on Wikipedia.  The STC is a calculation of the acoustic performance of a wall or ceiling and a higher number is better than a lower number.  While fiberglass insulation certainly improves the STC when compared to hollow wall cavities, dense packed cellulose offers more than twice the improvement and at a lower cost.

What about foam?

Adding Cellulose insulation to walls and ceilings is the most cost-effective and efficient way to minimize sound transmission between rooms or from the outside.  Having said that, the ideal construction method for sound proofing would be a staggered wall with foam insulation inside.  Staggering the studs creates an acoustical break for much of the sound flow (see the blue line).

Most customers are not willing to tear down their walls and build staggered ones as illustrated in this picture.  And while properly installed spray foam has a STC rating of 49, it can not be retrofit to existing walls and ceilings where the studs or joists are not visible.  In cases where the drywall or plaster has been removed, installing 3″ of foam costs double or triple that of cellulose or fiberglass.

The Wisconsin Department of Health Services states the following:

If your work includes disturbing, replacing or removing vermiculite insulation, you are required to work for a certified asbestos company and to use only workers certified in asbestos abatement, or to hire the services of a certified asbestos company to remove these materials for you.

Consider the law below before hiring an insulation contractor in Racine or Kenosha.

Enforcement of DHS Asbestos Regulations
View the DHS link

DHS 159.43 (3) states:

AUTHORITY TO INVESTIGATE.

(a) An authorized representative of the department may enter at any reasonable time any property in order to determine compliance with this chapter or s. 254.20, Stats., where the department has reason to believe that at least one of the following applies:
1. A person is violating or has violated any provision of this chapter or s. 254.20, Stats.
2. A regulated asbestos activity is being or has been conducted.
3. Asbestos waste or alleged asbestos waste is stored or disposed.
4. Business relating to regulated asbestos activities is conducted or records relating to a regulated activity are stored.

(b) The department representative may conduct tests, interview persons, take samples, review work practices, review and copy records, and conduct other activities to determine compliance with this chapter.

(c) An authorized representative of the department may conduct an onsite audit of a course to determine if an accredited training course meets requirements for accreditation.

(d) No person may refuse entry or access to any representative of the department authorized by the department to act under this subsection if that representative requests entry for the purposes of determining compliance with this chapter and the representative complies with par. (e). No person required to maintain records under s. DHS 159.19 (7) may refuse to permit access to records, refuse to provide original records to, or refuse to copy or permit the copying of records for, an authorized representative of the department, if that representative complies with par. (e). No person may obstruct, hamper, or interfere with the actions of the representative under this subsection.

(e) An authorized representative of the department entering the site of an investigation under this subchapter shall present identification and shall comply with applicable health and safety procedures established by law for persons engaged in asbestos abatement activities.

Vermiculite insulation

According to the EPA: 

“Currently, there are specific technical issues involving vermiculite sampling that can complicate testing for the presence of asbestos fibers and interpreting the risk from exposure. EPA and ATSDR are not recommending at this time that homeowners have vermiculite attic insulation tested for asbestos. As testing techniques are refined, EPA and ATSDR will provide information to the public on the benefits of testing that produce more definitive and accurate test results.”

As a result, it is best to assume that all vermiculite contains asbestos.

Vermiculite is most commonly found in attics, but was also used in walls.  It is often hidden under layers of other types of insulation.  Because it flows very easily, if there are holes from the attic into walls it can easily find its way from the attic to the crawl space, basement or even the living space.

While most documented cases of injury due to asbestos in vermiculite seems to involve workers, families of workers and people in close proximity to the mines,  it is prudent to be careful and let only experienced professionals handle vermiculite.  Its also the law. Read how serious the Wisconsin DHS considers anyone attempting to handle asbestos and vermiculite without the proper training.

If you find vermiculite in your home—-leave it alone—do not disturb it.  If you have recently hired an insulation contractor in Racine or Kenosha to work in your attic, they may now be responsible for having your entire home air sampled by a certified Wisconsn DHS Asbestos Inspector.  If the air sampling shows evidence of asbestos they are liable for the costs of abatement procedures and any health issues caused by exposure to you and your family.

Contractors should not remove or disturb any amount of vermiculite insulation unless they are certified to do so.  The Wisconsin Department of Health Services states the following:

If your work includes disturbing, replacing or removing vermiculite insulation, you are required to work for a certified asbestos company and to use only workers certified in asbestos abatement, or to hire the services of a certified asbestos company to remove these materials for you.

When handled correctly by a properly trained contractor, vermiculite insulation poses no threat to the insulation workers and home owners.  Surprisingly, a lot of vermiculite ore was shipped to Racine, Kenosha and Milwaukee.  It was then processed into the finished product, vermiculite insulation, and then sold and installed in homes throughout Racine and Kenosha.

The finished attic consists of separate sections that may require different sealing and insulating methods:

• The peak attic, located above the finished attic.
• The sloped roof or slanted ceiling wall
• Knee walls, between the finished attic and unconditioned attic space.
• Outer ceiling joists (floor), between the heated room below and the floor of the knee-wall

• Seal attic bypasses before insulating.
• Create an airtight and structurally sound seal in the joist space under the knee wall.
• When possible, insulate the slant wall with dense pack cellulose
• Insulate knee walls with dense pack cellulose or fiberglass batts covered with house wrap.
• When the knee wall area is used for storage, create a dam to hold back insulation and/or construct a cold storage platform to maximize R-value.
• Weatherstrip and insulate knee wall access hatch/panel to R19.

Once this work is done to the attic and knee-wall homeowners will notice a definite moderation of temperature of their upper level. This method of insulating also helps eliminate ice dams in this style of home.

1. Encloses the stud cavities to hold the cellulose in place
2. provides a vapor barrier
3. the reinforced thread allows the cellose to be blown in more densely

Why is this last item so important? Par PAC allows the membrane to be stretched tight over the wall studs and the insulation to be blown in under pressure so that it is more densly packed than traditional methods allow.  This eliminates the settling of the cellulose that can occur in other cellulose installation methods.

The Parpac membrane is installed over the walls to be insulated and stapled around all of the studs and headers. The membrane becomes “drum tight” and is ready for the insulation.

The next step is blowing in the cellulose insulation. Insulation is blown in to each stud cavity separately. The blower unit allows the insulation to be packed in to 3.5 pounds per cubic foot. This density prevents settling, provides more insulation and deadens sound transmission through the walls.

The advantage of the blown in technique is the ability to completely fill voids and gaps in the walls. Even walls with plumbing, wiring or electrical boxes are completely filled with insulation giving a much higher effective insulation value than is possible with fiberglass batt insulation.

The attic area presents other installation considerations. For instance, in the soffit areas the insulation should not go all the way to the roof line, nor should it cover the soffits. Air must be able to enter through the soffit vents and flow to the ridge vents. This keeps air circulating, the roof cooler and the attic from getting moist.

These areas used to be blocked with fiberglass batts before blowing in the cellulose insulation. But Energy Star certification requires a solution that will prevent wind washing. Racine Home Insulators, LLC uses special baffles that install over the soffit plates and prevent the cellulose from blocking the air flow. These  baffles also allow the insulation to be installed above the top plate, an area that typically is not well insulated and is an area of heat loss in a home.

The University of Colorado at Denver School of Architecture and Planning studied the energy conservation efficiency of two test buildings that differed only in the insulation systems that had been installed.

Building “A” was insulated with 5.5 inches of cellulose in the walls and R-30 of loose-fill cellulose in the ceiling. Building “B” received R-19 unfaced fiberglass batts in the walls and R-30 kraft-faced batts in the ceiling.

Over the two-month period a number of different tests and measurements were performed.

Here’s what the University researchers learned.

• In spite of the fact that tests showed Building “B” was about 12% tighter than Building “A” in the uninsulated state, after insulation was installed building “A” was far tighter than “B”. Calculations showed that cellulose tightened the building 36% to 38% more than fiberglass.
• An overnight heat loss test revealed that after nine hours (midnight to 9 a.m.), the cellulose-insulated building was 7 degrees F warmer than the fiberglass building.
• Most significantly, after three weeks of monitoring the cellulose-insulated building had used 26.4% less heat than the fiberglass building.

In their statement of conclusions the researchers note that results suggest cellulose performs as much as 38% better than fiberglass. The performance advantage of cellulose in temperate climates appears to be about 26%, and the report projects that “this benefit would become more significant in more severe climates.”

Cellulose insulation benefits not covered by the University of Colorado study include:

• Cellulose contains more than 75% recycled material. In accordance with EPA Guideline 40 CFR Part 248 it is the preferred (and in some cases required) building thermal insulation for projects involving federal funds.
• Since production of cellulose requires much less energy than mineral fiber insulation, which is made in gas-fired furnaces, and foam plastics, which are petrochemicals, the “embodied” energy in cellulose is much lower per “R” of insulating value than other materials. From the national perspective these savings at the production stage must be added to the superiority of cellulose as an insulator.

If you’re serious about saving money heating and cooling your home, about recycling and responsible use of resources, and about saving energy for our country the only insulation to seriously consider is cellulose.

Standards
Cellulose insulation is covered by the most comprehensive legal and voluntary standards of any insulation material. To be sold at all cellulose insulation must meet the requirements of the Consumer Product Safety Commission Safety Standard 16 CFR Part 1209. Most cellulose producers adhere to the much more stringent and comprehensive American Society for Testing and Materials Standard C-739 for loose-fill cellulose insulation and C-1149 for self-supporting spray-applied cellulose insulation. The Federal Trade Commission R-Value Rule applies to cellulose — as it does to all residential thermal insulation.

A number of qualified independent product testing laboratories have cellulose insulation certification programs to assure contractors and consumers that the material they buy and install meets or exceeds government and industry standards. The National Association of Home Builders National Research Center certifies the quality and performance of cellulose insulation.

The labels of underwriters Laboratories, the United States Testing Company, or other NAVLAP-approved laboratories, or the seal of the NAHB National Research Center are reliable indicators of safe, effective cellulose insulation.

If you want insulation that is best for the nation, for the environment, and for your checkbook, choose CELLULOSE!

Scientists, engineers, and contractors have realized for many years that the most commonly-used building insulation materials are really not the best insulators. Now this “conventional wisdom” of energy conservation has been confirmed and quantified through scholarly research.

How are the exterior  walls of older homes  insulated?

Dense Pack Tube Method – The Proper Way to Retrofit Sidewalls
The Dense Pack Tube Method is the only acceptable method for insulating side walls. In this method only one hole is drilled per stud cavity and a tube is inserted all the way up and/or all the way down. Only after the tube hits the bottom or top plate of the wall cavity is the flow of the insulation material started. Only if an obstruction is encountered when the tube is traveling up or down the wall does a second hole need to be drilled.  The tube method allows the material to be blown in under high pressure at all heights within the wall cavity. This provides uniform density of insulation material within the wall cavity AND enough pressure to compress the insulation material into the numerous small passages found in older walls. As a result, the wall is not only properly insulated, but it will also be functionally air sealed.

Directional Nozzle – Don’t pay For This!!!
The older method is called the directional nozzle method and results in a poorly insulated wall. This method should never be used – but some contractors have been doing it for decades and are unwilling to switch to more modern methods. In the directional method a nozzle is inserted into the stud cavity hole a few inches and the material flow is started. The nozzle tip has a slight angle to it and the insulation technician slowly rotates the tip as the material flows in. Unfortunately, the material can only flow 12-18″ away from the hole before it stops. Unless at least 4 evenly spaced holes are drill per stud cavity the result will be a poorly insulated wall. Over time the insulation will settle and in some areas there may even be voids. Racine Home Insulators have “re-insulated” a lot of these homes years later after an energy audit revealed the cold spots in the wall where insulation was missing or at very low density.

What is Air Sealing?

Will Air Sealing Lower My Heating and Cooling Bills?
In Racine and Kenosha, or anywhere in our cold Midwest climate, it is commonly known that air sealing can save the first 20% on annual energy bills. In order to save a lot of time, air sealing should always be done before adding additional insulation. Without air sealing the benefits of added insulation are often reduced to half or less because air easily moves through insulation, especially fiberglass.  When air moves through insulation it loses its ability to insulate. Specifically, open blown fiberglass and cellulose insulation require that no air be moving through them. To reduce air flow a homeowner will first need to air seal.

Skip Air Sealing and Expect to Pay Big
Many people overlook the need to air seal because they look around their house and see walls and ceilings that do not have holes to the attic or outside. What most people don’t realize is that all winter long they are heating the space behind their wall plaster or drywall. This space is the stud cavity. This is also true of the exterior walls if they are not insulated.

As the air inside the wall heats up it rises up into the attic while cold attic air sinks down into the wall. If attic ventilation is inadequate the attic temperature will rise and cause the roof snow to melt. The melt off runs down the roof until it reached the much cooler part of the roof along the gutter where it then refreezes. This is called ice damming and over time it will destroy the shingles, gutters and eventually the roof sub-floor. This is a huge problem and a very costly repair.

Does my home really have air leaks?
Most walls have a top plate and the air wouldn’t be able to flow up into the attic freely except for the fact that they have holes in them. When homes are built today these holes are required to be filled by the building inspector (see photo).

Consider that each room has a light switch that has to be connected to the overhead light. This means that electrical wire has to travel from the switch, up the wall, through the top plate, and over to the ceiling light. Second, baths and kitchens have at least one plumbing vent that has to exit the roof. These vents are iron, copper or PVC pipes that run behind your drywall. They run up the wall, through the top plate, and out the roof. Many are connected to a main “stack” which does the same thing, just a bigger hole. Last but not least, most homes have at least one vent fan and a chimney. If the home has recessed lighting, telephone, coaxial cable or an alarm system that run up to the attic there are additional “holes” that must also be considered.

Don’t forget that these are just the holes between your heated living space and the attic that we can NOT see. There are also the obvious holes or penetrations in the drywall caused by ceiling lights, switches and electrical outlets that have the wire running up into the attic.

Is Your Drywall Snug Against your Top Plate?
One of the most critical areas that need to be checked for air leaks is where the drywall meets the walls top plate. Because most construction lumber was used before being properly dried, the lumber continued to shrink after the home was built.

As a result, some homes have an 1/8 inch gap where the drywall once met the top plate. If this is the case in your home you will absolutely want to caulk and seal both sides of the top plate for ALL of your interior walls. If the exterior walls are not insulated with dense pack cellulose you will also need to caulk these top plates as well. The amount of heated air that can move through these seemingly small openings is phenomenal when added together. Consider a small 800 sq. ft. ranch house might have 80 feet of interior walls. That means there is a hole about the size of a 4×6″ photo (160 feet x 1/8 inch gap equals) or a 20 square inch hole.

Unfortunately, there is absolutely no way to visually inspect this area without crawling up in your attic. If you hire a home energy consultant, or have access to a quality infrared camera, you may be able to determine if sealing your top plates is necessary.

So how do I seal these hidden air leaks
Its not hard to air seal a house, but its definitely not fun. It usually requires crawling around your attic and wrestling with a bunch of old fiberglass or cellulose insulation. The materials are simple and consist of caulk and a caulk gun, spray foam, and probably some foam board for the larger spaces. All holes need to be sealed with caulk or foam.