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ICF vs CMU

34K views 39 replies 13 participants last post by  fjn  
#1 ·
okay.... this may sound like a dumb question but try not to blast me too bad.

The only type of home or commercial construction I have ever been apart of has been wood frame. 2x6 walls usually and always rafters for roofs. I recently purchased a small plot of land that I'd like to build myself a house on. It's going to be a long, drawn out project because I will spend my evenings and weekends there when I am free from my work and tending to my rental properties on the side.

I really enjoying following the ICF threads from Joasis and others. Such a fast moving and efficient form of building compared with stick framing. This house will be in a rural environment, prone to tornados and wind damagae. Instead of ICF, are there any advantages to building a home out of blocks instead? obviously you would need to add rebar and grout. Block are dirt cheap and still quite strong. With ICFs you gain a large insulationg factor.

Am I overlooking this?
 
#2 ·
Until you've been in an ICF home it's hard to explain the difference, but I'll try. Once you walk in and close the front door you immediately notice a different feeling. The house is quieter. Controlling your indoor environment is much easier and more cost efficient in an ICF home, weather it be heating or cooling. And you already know about the safety factor in a tornado.
 
#3 ·
Thanks for your response. The only reason I considered block is just because I've laid them before and I have some friends that are block/brick layers. I wanted something that would be strong and that I could work on in my free time.

The more I thought about it last night, ICF seemed much better once i started thinking about moisture and having to frame out the interior walls to insulate.

I haven't been able to find details online as to this, but this will be a ranch home with a full basement. How do you do the framing for the floor joists and subfloor? Do they make a block that isnt as wide so you can set a 2x6 on it for your plate? ive never seen that in any pictures on here.

Also, I realize unless you go with a concrete roof, your roof is quite vulnerable during a storm. anyone ever went with a steel roof like on a pre fab building? Use a thing and wide piece of steel as your top plate bolted into your ICF walls and use steel rafters instead of wood? Obviously, woof would be much faster but I'm going for strength and basically just intered in using materials other just stick framing my home.
 
#7 ·
with an ICF system you have many options for integrating the floor framing

as you can see.
if you only have an icf basement you can go the traditional sill plate way.
or you can cut out foam at specific locations to allow the concrete to flow to the face of the foam and pre place the ledger with l bolts.
or you can use the ICF LVL hanger system from simpson
or you can just decrease the size of the upper wall and have a ledge for the joists to bear.
 

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#6 ·
blocks are dirt cheap yes.
but what? are you just gonna live in a block shell?
with ICF you have your structure, insulation, vapor barrier, drywall nailing all in one.
The price looks a bit high when you first look at it, but don't let that discourage you. With a system like ICF you need to consider all the costs associated. Compare an ICF bid with a conventional construction bid. And add up the framing, insulation and vapor barrier costs and compare it to an ICF system bid. May be a bit different in your area but what Chris has told me is that in Ontario, Canada we could build a ICF house for only 2 or 3% more then a regular house...You pay a bit more up front yes
But by building with a product that will allow you to recoup those extra costs in your energy savings your doing the environment and yourself a favor.
 
#8 ·
Thanks again for the responses. I took the afternoon off and went and around and did some research. Framing pro, looks like you have really learned a lot from Chris working on his ICF projects. Thanks a lot for posting those drawing details.

The yard I went to supplys Fox Blocks....anyone ever heard used them? I've seen on here BuildBlock and Nudra I believe. This by no means will be a mansion, just a new place for me and a learning experience. The goal here is to build my home with cash and without having to go to the bank and to do a majority of it myself, minus septic, well, and geothermal.

Thanks once again. Insulation alone makes the numbers already better using ICF. That and I won't have to move about 5,000 cinder blocks.
 
#10 ·
I have seen many, many cmu structures go down in high winds, grout filled or not, and the insulation value is non existent. ICF's are the way. Take a trip north, or south, come and see one of us, and learn. You won't be disappointed.
 
#11 ·
Been checking out lots of websites the last few days and keep coming up with more and more questions. Since I have found the answer that ICF is clearly the way to go, I move onto some new questions.

Is radiant heating a good way to go? Do I really need to buy the bracing systems some of the ICF companies sell? Those prices are a little steep. Maybe I am over estimating how close together a typical 8 or 9 foot wall needs to be braced. Could I just buy a truck full of lumber and brace it that way instead using short screws, or is that not recommended?

Wood for window bucks or buy the steel bucks? I feel like I'm back in school again doing a research project trying to find out about this.
 
#12 · (Edited)
Rent bracing/scaffolding. Dont skimp, get more than you need, use all of it.

Radiant is an awesome complementing system to icf walls.

Also wood bucks are the way to go. Need nailers for windows doors and trim. Unless openings are complicated shape, no need to go to vinyl. Though they work sweet for radius lintels.
 
#14 ·
It's like anything else, rent more than 3 times - buy it, you'll get your money back. Also if you own it you will more inclined to go find ICF work cause they don't make any money when there not attached to a wall.

Wood bucks are common in residential construction because most window installers in residential don't know how to fasten to concrete
 
#15 ·
One could easily use 2x4's hinged with a brace and turnbuckle, and the only cost would be the turnbuckle from any concrete form company....if you cannot find any braces to rent.

I built my braces, and have never rented any...I probably have less then $2000 in the set. The real point is this: You must be able to adjust walls as you pour to maintain plumb and straight, and without experience, this can snowball into a disaster. Adjustable bracing is how we avoid this.
 
#16 ·
It seems most quality manufacturers provide spec manuals complete with prescriptive engineering details. I know Logix, our product we distribute, have them readily available on their website.

Download, read, keep handy, you will be pretty darn familiar if youve been innvolved much in the building process.

We do alot of consulting with inexperienced guys by starting first course and doing one course of rebar, then show up pour day to avoid level, plumb, bracing... and blowout problems. As well as i pour and show them how to vibrate behind me.
 
#17 ·
Such a fast moving and efficient form of building compared with stick framing.
I've never seen an ICF home done around here, so I'm not very familiar with them. They are not too popular, probably because we have moderate summers and winters, unlike Toronto, so the added insulation doesn't interest people enough to go that route.

But how long does the ICF process take? We used to frame houses with wood in two weeks start to finish, not including the time going back to do pick up work later. A custom home I'd give it a month to six weeks to frame.
 
#19 ·
Like said, way too many variables. Simple walls, quick. Off angle walls, radius windows, thin lintels, anything that gets away from standard block sizes and complicated rebar... makes for a long day.

Had a wall on last home that now makes us rethink if all walls need to be icf. Wall had so much glazing, was a vault, bayed out 15 degrees.... took three days to take care of. Could of framed it in three hours. Not so much benefit of the icf when 70 percent of wall is glass.

Most people see the block and think it will go fast. Then they see three bundles of rebar show up. Uh oh.
 
#20 · (Edited by Moderator)
All the homes I've been seeing go up in Illinois are stick builts like what I'm used to back in Michigan. Doing an ICF home is not for the faint of heart, as it can really turn into a disaster.

It is a cool system that performs really well. The estimated 2-3% higher cost for ICF is not accurate for Illinois. It will be substantially more than that. Going with a non traditional roof is definitely going to bump that number up real quick.
 
#21 · (Edited)
robcon,
I've done several papers on ICF Homes for my major and really believe they're the way to go. The numbers I've found for ICF homes as far as price comparison are .5-25% increase but you have to keep in mind, especially with the geothermal system that you mentioned you're going to recoup your losses much faster. As I've said I've never been on a build with one but I do know that after all the research I've done I plan to go into the ICF Home building business. Especially if you live in an area where High winds are an issue.

Google image search "ICF house post katrina" That should be an excellent example of just how durable these homes are.

Here's a link for some thermal images, Just scroll down some....
http://www.buildingtips.net/ez_vol5isu9.htm


From the research that I've done, its indicated that ICF homes also produce a self extinguising fire, meaning that if (God forbid) there ever was a fire, that the fire would end up smothering itself due to lack of materials to burn, now this s clearly only after its burned out all the interior walls and other combustible materials, but what I've come upon shows that you can rebuild relatively easily after a fire.

As far as the floor systems go, theres a bunch of different options, they make brackets that you place inside before you do the pour that you then nail through to secure the joists. I liked the concept of that system over some of the others, but theres so many that Its tough to say one of them is shades above the others.

Just figured I'd share some of what I've picked up but like I said, I'm no pro I just did a good bit of research on them for my papers, and eventually my thesis paper for my bachelors I think.

Hope that helped. Glad you chose ICF though!!!!

Ryan.

Edit: Don't forget that this can be used for a Passive house If you wanted to look into some of those building techniques.

Ryan.
 
#22 ·
Just figured I'd share some of what I've picked up but like I said, I'm no pro I just did a good bit of research on them for my papers, and eventually my thesis paper for my bachelors I think.

Ryan.[/QUOTE]


Bachelors = Cornerstone
Masters = thesis
Doctorate = Dissertation
 
#23 ·
ICF,s vs C.MU

My take,neither,this would be my choice. http://summitbrick.com/index.php/view/summit_brick_main_category/Structural Brick

Here are some of the reasons I think a structural brick has the others beat. ICF systems still need some type of exterior finish,with the brick you get the finish built in.You can design the rebar to address any load criteria like an ICF however,you can easily place insulation to suit any climate zone. Having done several structural buildings I can say quite assuredly they are more cost effective than an ICF veneered building.
 
#24 ·
ICF,s vs C.MU

My take,neither,this would be my choice. http://summitbrick.com/index.php/view/summit_brick_main_category/Structural%20Brick

Here are some of the reasons I think a structural brick has the others beat. ICF systems still need some type of exterior finish,with the brick you get the finish built in.You can design the rebar to address any load criteria like an ICF however,you can easily place insulation to suit any climate zone. Having done several structural buildings I can say quite assuredly they are more cost effective than an ICF veneered building.
Did you use insulation in the cores or line the inside with foam?
 
#33 ·
No, I did not miss the point. You could contend that by doing conventional brick exterior, that would count in your favor, but.....and this is where I was leading, at what cost?

We can do ICF's for $6 a sq/ft (area of the wall) and the exterior brick will cost about $4 a sq/ft, in this area.

So tell me about structural brick please. Include the total cost per sq/ft of wall, as I gave you above.
 
#34 ·
Approx. $14.00 sq.ft. in my area (N.W. In.) . Before you get to excited,unlike an ICF.wall with brick veneer,the structural brick will need only a 8" foundation to accommodate it. Some of those cost savings need be applied.

So the 5 times cost you suggested is not even close to reality. Also,why the heck do we, one of the wealthiest countries in the world constantly attempt to measure the worth of our buildings by how cheap we can build them vs aesthetics and posterity ????


I'm truly not interested in seeing how low I can go on price point.
 
#36 ·
Since were debating icf versus block here's my house. 6" block with brick veneer.

View attachment 102844



View attachment 102845


Looks good ! I too am a fan of composite walls vs. A wood framed building disguised to look like a masonry building.As author Steve Mouzon wood say "brick wallpaper applied to give the illusion that the building is built of a more prestigious material than mere wood ".