Good afternoon

This is my first post and I would really like to know more about exterior wall insulating and R values attained.

In 1987 I designed and had built a 2 story wood foundation, super insulated and passive solar home, R40 walls R60 attic. 23 years later it's time to downsize, but it has been a wonderful house to live in!

My wife and I are in the process of purchasing a city lot (no more septic and well) that will not allow a passive solar home. I'm looking at a better exterior wall system for sound deadening and economical to heat and cool, a smaller bungalow with walk out Basement.

Im in the Ottawa region, Canada and would like to meet and talk to someone in the area that has already built or used the ICF system to build.

What kind of R value is typical for the ICF walls and how do you super insulate?

John

PS I just joined and just started to read all of the information available, it is over whelming!

Hi JohnyH,

I'll bite, but be somewhat prepared for someone to knock this reply regarding the mythical "R" value of ICFs as it tends to get a lot of attention (feel free to research the forum).

If you look at the "R" value of many (NOT ALL) ICF forms, the "R" value as they sit, they are normally somewhere in the mid to upper 20s. That number would account for an R-value of EPS at 3.5 for every inch, then a R-value of concrete .28, and drywalls R-value of .45, paint's r-value, where the planets are currently aligned in the solar system, etc.

Now when you are dealing with an ICF wall and its overall performance as a system once constructed, the R-value is around 50 or so. That number takes into account thermal mass, reduced air infiltration, real R-value etc.

There are some that love to come on here and completely bash the idea of thermal dynamics, reduced air infiltration, etc for whatever reason and argue that isn't a true R-value. That is technically true when you are dealing with the true definition of R-value when it was created decades ago. That definition has become flawed in my opinion as technology (pink fiberglass insulation, spray foam insulation, EPS, ICF, SIPS, etc) used in construction has changed over the years.

I won't be surprised to find someone that challenges this response, but my significant research has led me to believe this is true and my thoughts will not change.

renangle

TF Systems is doing a seminar "close by" at Niagra-on-the-Lake in 5 days. This is a very easy system to super insulate. Here is the training workshop link and there are good technical details about the system.

The actual R value vs "equivalent" R performance will always continue. The only real change in the works that I have found is a concrete with an actual R value to it. (It is a LaFarge product). It is still low, but more than conventional concrete.

http://tfinsulatedconcreteforms.com/index.php?option=com_content&task=view&id=53&Itemid=88

ICF's R value is more expensive per square foot than most of the other systems. To get an Rvalue of 40 for the walls you need to add more insulation than the standard system has. Several systems will allow you to do this but the cost rises. You also will increase the depth of the wall because you have the concrete and then all that insulation added to it. That does not mean it is not a viable solution if you have other factors that warrant the extra cost. You will hear the term thermal mass a lot. The thermal mass in your area is only really cost effective if it is not buffered on the inside by insulation and your home is built to effectively use solar gain from the sun.

Thanks renanlge for jumping in, both feet I might add! I have done a lot of reading and have really started to wonder about the R rating given! I have located a few people that had used the ICF blocks at an early introduction to the area, 10 + years ago and they werent' happy with the heating and cooling costs. I am intersted for the sound deadening, I like quiet! The cost for being comfortable is also of very great concern! I'll keep reading and maybe attend a seminar or two, it would be nice if they were closer though! The lack of having some passive solar help is a bit disconcerting but the availability of serviced city lots with the correct orientation or few and far between and expensive!
 
Thanks John

John,

You are more than welcome and best of luck on your research. ICF walls have a sound classification of around 60 or so, thus they are exceptionally quiet. The only thing you will hear outside are whatever sound transmits through the windows. Also, there will be no settling of the house and much less maintenance.

With regards to the energy rates and what they may actually be in your neck of the woods I cannot really comment. I do know that the clients I work with have had no complaints. I do know that Energywise Structures (google them) can perform an energy assessment before you build and will guarantee your energy costs for 2 years. They will look at your location, wall technologies considered (frame, ICF, tent), the windows, and HVAC give you the numbers. I have worked with them before and don't have any complaints.

renangle

Here is an article on the mass effect. It is worth reading and book marking.

http://www.buildinggreen.com/auth/article.cfm/1998/4/1/Thermal-Mass-and-R-value-Making-Sense-of-a-Confusing-Issue/

Another article

http://www.buildinggreen.com/auth/article.cfm/2007/10/30/Thermal-Mass-What-It-Is-and-When-It-Improves-Comfort/

There are several articles regarding R-value, thermal mass, tight envelopes, etc and I am not going to try to argue with them. All I know this....my company was involved with building a 1400 sqft ICF house for Habitat for Humanity in Virginia during 2007.

The interesting thing was the ICF house was being built next to another Habitat House that was the exact shape and size. Both houses were completed at the same time, both had the same windows, HVAC, and both houses were certified as "Energy Star" homes. Because of our involvedment in donating the materials for the house, we were given access to their actual utility bills for the first two months of occupation.

Below are the actual rates...
Kilowatts Mo. Elec. Bill Kilowatts Mo. Elec. Bill
January-08 848 $59.36 1563 $109.41
February-08 871 $60.97 1554 $108.78


Call is what you will, but I'll take the less expensive electrical bill. As for the owners, the ICF owner really loves her house and the neighbor in the other house really likes the ICF house too.

We have no idea if the other homes is less rvalue or is well sealed.
We have no idea of that we are comparing apples to oranges or that on home is running all kinds of electrical equipment.


We have no idea if one gets more shade than the other, or has more solar gain.

Utilities bills prove nothing when taken out of context.

On the contrary, the utility bills are the bottom line as far a realworld living is concerned. One can expound endlessly about all the variables, but for the family living in the house, year after year, the savings on the utility bill is the constant positive effect of living in an energy efficient home. I can think of no better example of why we promote the construction of energy efficient homes.
These numbers, if promoted properly, would do more for developing an acceptance of alternative construction techniques by the general public than anything else. And if the public wants something bad enough, the building industry will give it to them. You just have to convince the public that they really do want energy saving more than they want granite countertops. These kinds of numbers will do that.

I agree, I have no clue on what the R value is for either home or if one is using 200 watt light bulbs in every room for two months.

I do know that both houses are 1400 sqft, with the same floor plan, same siding, same electrical, same washer/dryer, light fixtures, refridgerator, dishwasher, TV, etc. Both houses are also energy star certfied, so they are technically energy efficient.

Two people were living in the frame house and 3 people in the ICF house. The only difference aside from possible shade and there are trees outside both houses, would be one is built with frame and one is ICF.

Sorry Wes but the utility bills alone prove nothing but that one home is using less electricity than the other, not on what the electricity is being use for.

For all we know the one home has a bunch of lizards for pets and is running heat bulbs for them. Maybe one family is doing the laundry for their extended family. Too often people in the industry quote numbers and figures but they exist in a limbo that proves nothing.

I'm generally with Wes and Ren. The proofs in the pudding. I'm curious about what (jmagill) is saying that " ICF's R value is more expensive per square foot than most of the other systems." What other systems are you talking about? I have not found that to be the case here. In fact to the contrary. When one goes down the path of trying to design up to the performance of an ICF -- usually their  system starts looking more and more like an ICF.

Also, I suggest you go and read the 100 threads or so about thermal mass. It would be hard to recap the data here. Regards.

P.S. Have a very long list of happy ICF owners. In some large houses (coupled with a good roof design) differences in monthly electricity bills sometimes exceed $1000. But perhaps more important -- where it really matters --- in the 200 or so small homes in Lubbock Texas (about 1000 square feet or so) built by the City of Lubbock --- differences may be only $50-$100. Now the amount may be smaller but the difference is huge. BTW -- Richard Rue (of Energy Wise mentioned above) number is (817) 385-5335. Regards.

First, I did not say ICF is not a good product or that people will be unhappy with it.

I did say that if you price out the same home with ICF and say SIPs and spec the same R-value for the walls , ICF will be more expensive. In other words if you price for square foot of wall area ICF is more expensive for the same R-value.

This is a good article as well.

http://www.cmhc-schl.gc.ca/odpub/pdf/65863.pdf

"The ICF wall assembly studied in this research project had an
insulating value that was fairly close to the nominal insulation value of
the polystyrene layers of insulation. While minor thermal bridges
through the wall system were detected, the more severe bridges that
were found were due to penetrations through the ICF system and did
not represent a weakness in the ICF wall system.
No thermal mass impact or higher effective insulation value was
observed. However, the air leakage testing found the building to be
relatively airtight and this can, for the most part, be attributed to the
ICF wall system. The energy savings associated with the reduced air
leakage alone are significant and would continue to accrue over the
life of the building as the amount of air leakage through the ICF wall
section would not be expected to increase to any great extent over time.
Additionally, the ICF wall system provided a significant thermal buffer
between indoor and outdoor conditions, which would provide for
enhanced comfort conditions within the building."

SIPs was more or less where i thought you might be going.  Here (Texas) SIPs are usually more expensive than ICF -- especially the more complicated the job.  Kinda like pricing roofs for SIPs -- when the roof is complicated SIPs get expensive.  Perhaps you should start another thread about a SIP or two that you'd like to discuss.  

One of the better thermal mass reports is by Oakridge Labs on Thermal Mass http://www.ornl.gov/sci/roofs+walls...index.html


(However even this report is often misquoted in a few ways -- misuderstandings of the report are usually based on the exact focus of the report -- In order to fully isolate thermal mass and determine it's value (good or bad) all systems (low mass or high mass) have the same r-value.  Really, if you don't do this you really can't isolate the thermal mass contribution one way or the other. 

Also, people sometimes use the report to say that it is important to "uncover" the mass on the inside so that it may more properly radiate into the room.   This is actually somewhat of a trade off -- an insulated mass still has thermal capacitance and even greater lag and it can absorb heat more quickly that might otherwise stay in the room.  The fact is an uncovered internal mass wall performs a tiny bit better in the report than a typical ICF wall.   The part that is left to the imagination is that if we are comparing (lets say an R-22 6" concrete ICF wall)  to an internal exposed mass system with approximately R-22 or so on the exterior and then 6 inches of concrete on the interior (same r-value- same mass).  Thus unlike ICF,  the system that performs a tiny bit better than ICF is one very rarely seen in the real world.  This system would take some work to put up and then you'd still have a time hanging pictures or running your electricity.

Perhaps more importantly, people will quote the report to say that ICF only performs 8% better in Minnesota than conventional construction or low-mass construction (e.g. SIPs).   That's not what the report says at all.  It says ICF will perform 8% better in Minnesota than convential construction or low-mass construction (e.g. SIPs) built to the same R-value  as the ICF.  Again, in the 2x6 world getting to R-22 is not as easy as it sounds the r-value of wood at approximately 1 per inch and with 15 to 20 percent of your envelope studs and headers having this r-value.

regards.

Posted By TexasICF on 08 Apr 2010 05:42 PM
  That's not what the report says at all.  It says ICF will perform 8% better in Minnesota than convential construction or low-mass construction (e.g. SIPs) built to the same R-value  as the ICF.  Again, in the 2x6 world getting to R-22 is not as easy as it sounds the r-value of wood at approximately 1 per inch and with 15 to 20 percent of your envelope studs and headers having this r-value.

regards.

Yes, that is all true. The mass and the concrete provide additional benefits both with air infiltration and thermal mass. The fact is that you pay extra for those benefits and in most climates (and especially Canada) it is usually more cost effective to put your money into more insulation, unless the concrete supplies you with something else that is important to your building envelope. ( solar flywheel, earthquake strength, noise abatement or fire protection as a few examples).

To put this all in perspective. I live in a SIP home. I will be building a new home and I will be using ICF's and SIPS. I will be using a ICF product that will allow me to have the insulation completely on the outside. I will be using the product for it's strengths all the while knowing exactly what its costs and weaknesses are.



Time and time again I see people on this website only tell the good and leave out the negative. That does a disservice to the entire ICF industry.