Home Insulation Is One Of The Best Ways
To Save Energy

If so, you know that home insulation should be high on your list of priorities.

There is an awful lot of information out there — maybe too much.

Let's try to simplify it by looking at the questions I was asking myself when I embarked on this project, as well as the answers I found.

As with all other aspects of this project, I am documenting this home insulation process step-by-step. You may want to visit these other pages as well:

• Spray Foam Insulation
• Foil Insulation
• Vapor Barrier
• Water Heater Insulation

NOTE: Because I live in a cold North American climate, the information in these pages is based on that fact; it may have to be adapted to your own circumstances if they are different from mine.

WHY INSULATE?

Apart from the moral issues...

• Concern over the effects of global warming and what to do about it;
• The desire for a smaller personal ecological footprint and a reduced carbon footprint;
• Belief in a system or way of life such as permaculture or voluntary simplicity;

...there are the practical issues:

• The immense satisfaction of knowing that thanks to the right kind of insulation in the right place your home is as energy efficient as you can afford to make it;
• The plain, unadulterated comfort of a living space that is warm and draft-free in winter and naturally cool in summer;
• The financial rewards that keep coming month after month, in the form of a low power bill;
• In my case, the desire to achieve -- and even surpass -- the energy efficiency goals outlined in my energy audit and qualify for the grants and incentives being offered to homeowners by the different levels of government.

WHICH PARTS OF THE HOUSE NEED INSULATION?

Some of the areas requiring insulation

The good news is that many of these are DIY -- or do-it-yourself -- insulation projects!

EVERY SITUATION IS UNIQUE

Since the very inception of this project, I knew what my goal was, since that goal was the very raison d'être of the project:

1. To reduce my housing expenses enough that I would be able to live out my old age on my modest government pension, if necessary;
2. To accomplish this without abandoning the principles of permaculture that had played such a huge role in my life in the last decade and a half;
3. All this within my budget, circumstances, and abilities.

Ready, Set, Go!

From the start, it was imperative that the house be entirely paid for. In trying to foresee the future, I realized that if I ever had to live on my retirement pension alone, my income would not be sufficient to cover a mortgage.

So, I bought a house for $10,000. I had enough savings for the modifications (I hoped!).

The house had to be very inexpensive because in order to apply the quantity and quality of home insulation that was necessary in order to seal it well against the elements, every wall and ceiling had to be stripped completely.

Because of my commitment to make this as green a project as I could, instead of demolishing, wherever possible we used the deconstruction method which is described in my deconstruction page.

The house, with gutting completed, ready for home insulation

After a full year of studying my house, trying to figure out the unfamiliar and capricious Maritimes climate, researching every possible kind of home insulation,, consulting with suppliers and experts, getting an energy audit, and finding out what was available to me locally (remember: I live in a small province, in a tiny remote village - but also I believe strongly in encouraging the local economy), I concluded that the following areas had to be insulated:

A. Main building (including bathroom & stairwell):

• Two outer walls
• Stairwell inner wall
• Main ceiling
• Stairwell ceiling
• Attic hatch/ladder unit

B. Sunroom-office addition:

• Three outer walls
• Cathedral ceiling
• Floor

C. Kitchen-dinette addition:

• Three outer walls
• Cathedral ceiling

D. Crawl space (under kitchen-dinette):

• Three outer walls
• Outer sill plates

E. Main building basement:

• Sill plate on all four sides
  (inner walls as well as outer walls)
• Laundry room walls
• Stairwell wall

1. Attic: nothing was added to the attic this first year. It was decided to go through one winter in order to determine — by monitoring the temperature upstairs — just how effective the low-density main floor ceiling insulation/vapor barrier combination would be.
   
   (Note: the attic is actually the former second storey of the house, which has been sealed off. There is already some insulation in the ceilings (under the roof) and the rooms are finished and the floors carpeted.)
   
   Therefore, if you need information about attic insulation now, Green-Energy-Efficient-Homes.com is an excellent site that covers attic ceiling insulation.


2. Basement walls: there are cracks in the foundation which have been allowing for some water infiltrations under extreme rainfall conditions (which are getting more frequent, due to climate change).
   
   Until the ground has been re-graded, window wells, eaves troughs and drain tile installed -- all of which should take care of the moisture problem -- there is danger of introducing mold problems if we cover up those walls.
   
   If the planned measures don't cure the problem, and because my budget doesn't allow for extensive foundation work, the basement will remain as it is -- and a dehumidifier used in summer.


3. Basement ceiling: I have looked, I have asked, but I can't get a consensus on whether basement ceilings should be insulated or not. Therefore, I am reserving that decision until I get more information. Cold floors are not nice, but I like Oriental rugs and have quite a collection!


4. Crawl space ceiling: some of the above arguments apply, except that the crawl space walls are insulated and the dirt floor is dry and it will have a good vapor barrier. I will have to monitor the temperature closely because of the water pipes going through that area, which is to the north and has its walls exposed on three sides -- at least for the moment.
   

KEY: A Main Building; B Sunroom-Office; C Kitchen-Dinette;
D Crawl Space; E Basement Under Main Building

DON'T FORGET TO SEAL AIR LEAKS!

This is because insulation does not reduce air movement through cracks between building parts. (Spray foam, particularly the high-density type, is somewhat efficient at this, however.)

For example, controlling air movement within a wall cavity will not stop air that leaks between the foundation and the sill plate or between the wall joists and a window frame.

The following illustration shows just some of the places where air can unknowingly enter the house, and greatly diminish your return on your home insulation investment.

Once you know where your house is leaking, get a hold of a caulking gun and some inexpensive caulking, and caulk, caulk, caulk.

Of course, if you're doing some major remodeling, a vapor barrier is the way to go.

WHAT ARE THE DIFFERENT TYPES OF HOME INSULATION?

No wonder there's confusion out there!

WHY SO MANY DIFFERENT TYPES?

The reason that there are so many types is that not every type is appropriate for every situation.

For example, the main factor in my decision to use spray foam insulation in my house was the fact that most of the walls and ceilings in old houses like mine are made up of wood planks. (Newer houses have panelled walls, similar to the photo, below.)

An old wall and a modern wall

As you can see, old planks have spaces between them. They also have cracks, knots and warps.

It's easy to see why conventional batt insulation (be it fiberglass, cotton, or whatever) cannot do a thorough job of keeping the cold out of that kind of wall.

Rigid foam insulation is even worse. It's impossible to obtain a bond between it and an old wall of planks.

Spray foam, on the other hand, penetrates the cracks, gaps and knots, and seals them. The denser the foam, the better the seal.

Yet I have not read about this anywhere. It was a friend who warned be about it. Merci, Louise!

Check the Resources at the bottom of this page for details about the different types of home insulation and other relevant information.

HOW MUCH HOME INSULATION IS ENOUGH?

Then, depending on whether your home insulation will be a DIY project or not, it's just a matter of talking to the store, contractor or supplier to get an estimate of the quantity and price.

WHEN "WHAT" MEETS "WHERE"...

1. Main building - walls and ceilings: low-density (1/2-lb.) Home Foam brand spray foam, between all studs and joists (four good inches), sprayed full and trimmed.


2. Walls of the two additions (sunroom/office and kitchen/dinette): low-density (1/2-lb.) Home Foam brand spray foam.


3. Cathedral ceilings (sunroom/office and kitchen/dinette): four inches of high-density (2-lb.) BASF Walltite brand spray foam (also known as "blue foam"). (PDF file)


4. Kitchen-dinette exterior walls and cathedral ceiling will benefit from additional insulation via a layer of reflective insulation/vapor barrier of the "foil-bubble-vinyl" type. This was judged necessary because of the windy northern exposure of that part of the house.


5. Crawl space walls and sill plates: high-density Walltite spray foam.


6. Main building sill plates: the same high-density Walltite spray foam.


7. Sunroom/office floor (where the foundation is a concrete slab): 1-1/2 inches of rigid foam insulation installed

   (a) over a ledge which was nailed near the lower part of the 6-inch floor joists, but
   (b) six inches away from the three outer edges.

   Those six inches - which encompassed the sill plate - were then filled with high-density Walltite spray foam. As well, the rigid foam was topped with two inches of high-density Walltite spray foam.



8. Basement laundry room walls: fiberglass batts reused from the original ceiling insulation (R-00).


9. New stairwell walls: purchased fiberglass batts (R-00)


10. Attic: nothing was added to the attic this first year. It was decided to go through one winter in order to determine - by monitoring the attic temperature - how effective the low-density ceiling insulation/vapor barrier combination would be. (Note: the attic is actually the former second storey of the house, which has been sealed off.)


11. Attic hatch/ladder unit: This has yet to be installed at this writing. However, an effective foam and/or rubber gasket is planned, as well as a light "mattress" that will sit on top of the whole contraption.

HOW DOES HOME INSULATION WORK?

During the summer, heat moves from outdoors to the house interior. To maintain comfort, the heat lost in winter must be replaced by your heating system and if the heat gained in summer is excessive, you may need air conditioning. Insulating ceilings, walls, and floors decreases the heating or cooling needed by providing an effective resistance to the flow of heat.

Batts, blankets, loose fill, and low-density foams all work by limiting air movement. The still air is an effective insulator because it eliminates convection and has low conduction. Some foams are filled with special gases that provide additional resistance to heat flow.

Reflective (or radiant) insulation – also known as "radiant barrier" – works by reducing the amount of energy that travels in the form of radiation. It reflects some of the heat back where it came from. Check out this link for a good explanation of the principle of reflectivity. (PDF file)

That's the type we used in the kitchen-dinette. Yo can see the step-by-step here.

An insulation's resistance to heat flow is measured or rated in terms of its thermal resistance, or R-value.

WHAT ON EARTH IS R-VALUE?

However, the way the insulation is installed plays a large role in its effectiveness. Compressing the insulation, leaving air spaces around it and/or allowing air movement within it all reduce the R-value of the insulation.

Some typical R-values:

• Fiberglass batts or loose fill: 3.0 to 3.7 per inch;
• Cellulose fibre (loose): 3.0 to 3.7 per inch;
• Rigid board: 3.6 to 6 per inch (depending on type);
• Low-density spray foam: 3.6 per inch;
• High-density spray foam: 5.8 to 6.8 per inch.

There's a detailed list at the CMHC website.

WHICH R-VALUE GOES WHERE?

As mentioned earlier, we did not insulate the basement walls, nor the attic, but our exterior walls, with 4 inches of low-density foam @ approximately R-3 per inch, surpass the goal.

For the crawlspace walls, we are short by a wide margin (approximately R-10 against a goal of R-24), but the cost of the additional two or three inches was prohibitive at this time. In addition, that wall, which is exposed at present, will end up buried once the land has been regraded -- and earth is an excellent insulator.

You can use this U.S. Department of Energy's Calculator to determine the R-values recommended for each area of your house.

While you're there, check out their Insulation Fact Sheet.

The Canada Mortgage and Housing Corporation has an excellent section on home insulation too.

Both sites offer more information than this little website can possibly supply.

HOW MUCH DOES IT COST?

There are and will be other types of insulation used in my house, as well as vapor barriers -- making the insulating and air sealing of the house the most expensive part of my whole project.

According to the contractor's estimate, the above cost breaks down as follows:

• $2.50 to $3.00 per square foot for the basements (BASF Walltite 2-lb foam);
• $6.00 per square foot for the cathedral ceilings (BASF Walltite 2-lb foam); and
• $3.00 per square foot for the walls (1/2-lb low density Home Foam).

The differences are due to the thickness of the application (from 2 to 4 inches, depending on the area).

I do not know how much other types of home insulation would have cost, as I was determined that spray foam was the only type that would justify going to such lengths and expense -- gutting the house was a major project in itself and could only be feasible if it was fully taken advantage of.

Given my age (67), it may seem foolish to invest so much money in this way. It's probable that I will never recover my investment.

On the other hand -- and I've mentioned this before -- what if I find myself having to live on just my retirement pension some day? I don't want to risk seeing the major part of my income go towards heating bills -- ever.

Every part of that house is being planned for my old age: the single storey, the level entrance, the wide doorways -- and of course the energy efficiency. Peace of mind has its price.

WHAT IS THE PAYBACK PERIOD OF HOME INSULATION?

Let's say you're planning to increase the level of insulation in your attic -- from R-19 (6-inch fiberglass batts with moisture barrier on the warm side) -- to R-30 by adding R-11 (3.5 inches of unfaced fiberglass insulation batts).

Your furnace is gas with an AFUE (efficiency rating) of 0.88. Cost of gas is $0.87/therm.

Well, according to the formula explained on this U.S. Department of Energy page, "Estimating the Payback Period of Additional Insulation", it will take you 5.62 years.

WHAT? NO SOY?

There is only one type of soy-based foam insulation, and it's the high density, 2-lb kind.

That means it's expensive.

I found a contractor who works with it and got an estimate. At $17,809, it was more than double the other estimate.

To be fair, it did include some additional square footage, namely the two outside basement walls.

And of course, I would be getting better R-values, perhaps more than I really needed.

However, at my age, I just could not justify the extra investment. I would have to SAVE an additional $8,000 in my lifetime -- say, 20 years -- or $400 a year. Not just a $400 a year saving, but an additional $400 over what I would save with the mix of spray foam insulation types that I was planning on having.

It would be possible, I suppose, but I didn't think it was worth taking the chance.

Some of you will be thinking, "What about the environmental factor? Isn't spraying your house with soy (and recycled plastic bottles, another ingredient) like buying organic food: you pay more for your ethics?"

In a word, No.

After I got this estimate, I decided to ask questions. I wrote one of the soy-based foam manufacturers and asked what was the percentage of soy in the foam. I got this reply:

Assuming that it's half and half, the foam would only be 10% soya oil.

Recycling plastic bottles sounds good, but personally I'd rather see them not being used in the first place, and I do not use them myself. I don't even want them in my walls.

In addition, the extraction of oil from soya beans and the recycling of plastics are both energy-intensive processes.

Enter Monsanto

And then, there's the little matter of Monsanto controlling practically all the soy crops in the world. Not just the beans, but the seeds as well. Thanks to Monsanto, most of the soy being grown in the world comes from genetically-modified seeds and Monsanto holds the patent.

Monsanto is one of the worst companies in the world. If I used soy-based insulation, I would end up knowingly putting money in its pockets.

The above video is part of a film by an independent French director, Marie-Monique Robin, "The World According To Monsanto". You can get the story and the background by visiting the Greenpeace website. To see other parts of the film, click on the link under the video.

For more information about Monsanto, the Organic Consumers Association has a very informative page on its website.

DOLLAR-BY-DOLLAR ACCOUNT

THE OTHER BOTTOM LINE

STEP-BY-STEP PHOTOS

1. Spray Foam Insulation

2. Foil Insulation
   
   

   RESOURCES

   The Canada Mortgage and Housing Corporation (CMHC) website has a very useful Fact Sheet on Insulation in their "About Your House" Series.

   The Old House Web has an excellent section called Insulation: The Facts.

   There is an abundance of information about home insulation online; by all means use the web for your research, but be sure that the advice you get is from an independent source.

   WHAT ABOUT YOU?

   Do you have a home insulation story that you'd like to share? Please contact us and we'll include it here.
   
   

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   SUMMARY: TWELVE TIPS ON SPRAY FOAM INSULATION

   If, after researching the subject, you decide that insulating your new home, -- or retrofitting your existing home -- with spray foam home insulation is the way to go, here’s what I learned from my own experience:
   1. Get as many estimates as you can, and make sure they all cover the same areas with the same R-values, so you can compare apples with apples.

   2. Get as much information and explanations from the home insulation contractors as you possibly can. In our case, for instance, we used a very good suggestion from one contractor to get a better result from another contractor. So, ask questions, point out possible problems, etc.

   3. If you’re retrofitting, gut the inside completely. Instead of demolishing everything, do as much deconstruction as you can.

   4. Prepare your surfaces carefully by removing all nails, especially if you’re going to be using low-density foam. Trimming off the excess with a saw requires that all studs be nail-free. The home insulation contractor will charge you less if he doesn’t have to do any preparation.

   5. Make sure that all the other trades (plumber, electrician), have got all their roughing-in done to the point where the pipes and wires that are in place can be completely buried in foam insulation.

   6. Go over everything once before “D-Day” with the home insulation contractor. You will then have time to have details rectified before it’s too late. Or to have that forgotten fixture put in.

   7. Vacuum everything. Even if the contractor tells you it’s not necessary to get rid of the dust, it just makes sense that if you want the foam to adhere properly and get into every cranny, the surfaces have to be clean.

   8. Make sure that the product name, the number of inches and the expected R-value are all specified and guaranteed in the contract.

   9. Get a respirator for yourself if you’re going to be around – and you should be. Check for missed spots, point them out to the installer and have him rectify them before you pay him.

   10. Get earplugs as well! The engines that are out in the truck, on the street, are extremely noisy.

   11. Warn the neighbors in advance, about the noise and how long it will last; they may want to stay away. (The contractor can tell you how long it will take.) Better yet, invite them in for a peek and rave about the money you'll be saving -- they may decide to insulate their house too!

   12. Sit back and enjoy your energy efficient home!
   
   
   
   

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   GREEN NOTES

   
   
   WASTE. From the beginning, I have said that my green home project would not, could not be 100% green. One can only do what one can and can afford.

   And I have said that I would tell all and show all. Did I know that spray foam home insulation produced mountains of waste plastic? I didn't. Would I have changed my mind about using it? I don't think so. It's one of the trade-offs for the future decades of energy savings that I will generate.
   
   I hope someone finds a way of recycling that stuff, soon, though.

   

   A mountain of waste foam insulation
   

   WASTE NOT. On the other hand, the pink batt insulation in the following picture is part of what we salvaged during the deconstruction phase. It was perfect for this basement laundry room. It looks dirty because it is! We didn't think a little dust warranted wasting material which was perfectly reusable.
   
   

   

   Salvaged fiberglass insulation batts are being reused
   in basement laundry room walls
   
   
   USE OF PLASTIC. As if it weren't enough that my walls are full of plastic, as I write this there are people in my house covering all the walls and ceilings with... more plastic.

   It's called vapor barrier and it's absolutely essential, at least in this climate. (Actually, it's optional where high-density foam is used but I'm applying some anyway because it also helps seal the house tightly and reduce the effect of thermal bridges.
   
   

   

   Vapor barrier goes directly over spray foam home insulation.
   Black gunk is acoustic sealant; it ensures a tight seal.
   
   
   

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