Eco-block homes

I just heard of these today- here is the website I looked at- www.eco-block.com . Does anyone here live in one, or know someone who does? Are they as energy efficient as claimed?

[Witterbound]

I built my two below-ground basement walls with a similar product called Arxx blocks. I like them alot, but I wouldn't want a whole house built out of them. It would cost too much, in my opinon. I'm pretty sure the R value in the walls is about the same as the R value in a 2x6 wall. Of course, the blocks block the airflow, which also helps with energy costs.

[rzrubek]

My wife's Uncle in eastern AZ built his house from something very similar to these (not sure what brand of ICF he used) and he is very happy with the results. Built the house himself.

[Callieslamb]

We looked at them and would have loved to have used them. They were just too expensive though compared to stick built.

[Dexter]

I just did an incredible amount of research on this (ICF, insulated concrete forms). Plan was to build my entire basement with it.
Had the designs engineered, builders quoted, etc etc. Turns out that it is not only expensive, but there can be unforseen problems. Main thing I heard was air cavities in the walls.
Because there is no plywood pulled off of the set concrete, you never see the final job. Which is scary.
It is toted as "easy" to do, however anyone who has seen them fail will tell you to get someone with plenty of experience. Or, just use formed concrete.
Formed concrete with added styro insulation does the same thing, for less.

[Witterbound]

My friends and I set all the blocks, but then I paid an experienced crew to inspect our work, finish the reinforcements, and do the pour. It took 8 of us two long days to set the blocks. A big part of the time is in cutting and laying the rebar and leveling the blocks. It's a job a handy do it yourselfer and friends can do. Most of the cost is in the blocks themselves. I believe they ended up costing about $5 a square foot if I rembember right. Then there are extras you have to buy, like termite barrier, waterproofing, etc. My hunch is that you could save money if you stick frame the walls then have insulation sprayed into the cavities (which isn't inexpensive either).

ps, I'm in Arkansas too.

[haypoint]

There are several companies that make preformed foam forms. Most are just foam on each side with a plastic tie to hold the wall to a specified thickness. There is also a type that has foam connecting inside and outside. They take less concrete. The forms allow concrete to fill the voids and the result is vertical columns and horizontal runs of concrete.
While all such systems are expensive, if you were going to pay someone to set up metal forms and pour the walls, then add rigid insulation inside and out, this may save some money if you set it up yourself.

[WisJim]

My son used to work for a friend's construction company that used these types of blocks in some houses they built, with no problems, and good homeowner feedback. Another friend recently built a new house using ICFs and really likes it, and highly recommends that type of construction. I would seriously consider it if building a new home.

[ibcnya]

I have spoken about this before in this forum but I'll do it again. I built a 1500 sq (50x30) ft home in 02-03 using the Arxxx forms. I wanted to build a berm home open to the south and had a difficult time justifying the rental cost of concrete forms so I went with the ICF's and even took a one day $100 class to become a contractor. That was the best $100 bucks I spent concerning the pouring of the walls. I started setting the forms on my footings early one Friday morning in July of 02. Hot! The reflection of the sun coming off the white forms was intense!. By the end of the day I had all the forms up with rebar snapped in place and lots of it. I had to rent the braces which also serve as scaffolding on the inside of the wall from the wholesale place I bought the forms from and they were simple to handle. Saturday morning I had myself and 2 brothers and here comes the first load of concrete. Because it was a berm home I was just deep enough in the ground so I didn't have to pump concrete. (another cost saver) We poured all the way around about 3 feet high and I had rented a concrete vibrator to get as much bubbles as possible out and leave no air pockets to strengthen the concrete. By the time he came back with the next load the first load of concrete was setting up and we did the same thing all away around thing again vibrating along the way. I'm proud to say I had no blowouts thanks to the $100 contractor class. We ended up doing 3 loads that day and it must have been 110 degrees with the sun reflecting off those white walls. My brothers and I still talk about that day once in awhile. Hehe.
Now I can say "I LOVE IT". I have in-floor heating and have never hooked it up because it stays so warm in this house in the winter. All I have is a small wood stove in the kitchen and it heats the whole house. I put 3 layers of bricks on the stove and covered it with a metal shroud. (Looks like part of the stove) I burn an arm load of wood once a day during the winter and that's it no kidding. The bricks retain heat all night long. We went to Florida in January 2 winters ago for a week and came back and the house was 52 degrees.

[PyroDon]

Ive seen these in use , Ive also seen what happened when they tried to pour too much at a time (blow outs ) .
one thing that I have noticed is the values claimed dont seem to work out.
in part this is due to the thermal mass of the curing concrete which generates heat
Cost wise and insulation value is not really any better than a standard poured concrete wall wrapped in ridgid foam . strength is considerably less than a poured wall .
Now pouring concrete is one of those things better suited to those who have the equipment. figure a standard basement , by the time you figure the cost of the concrete, renting forms and your time its a lot cheaper to have a company that specializes in basements do the job. this is why builders use subcontractors it saves them money and time .

[SolarGary]

Hi,
Several new homes have gone up around here lately with ICFs. Seems like a pretty good way to go.

I believe that the energy reduction claims are overblown. One careful study on a ICF building showed that the R value was equivalent to just what the polystyrene insulation would have provided -- the thermal mass of the concrete made little difference. The R value for the 4 inches of polystyrene would be about R16 -- so about the same as 2X6 stick wall on 24 inch centers with some thermal bridging.
There was a study done by ORNL using simulations that did show some improvement in effective R value due to the concrete mass -- it makes the most difference in moderate climates and not as much in cold climates. The study is at the link below.

Some reports and information here:
http://www.builditsolar.com/Projects...tionps.htm#ICF


Gary