Hi there,

I'm new to this and just starting doing some research on green building.
We are looking into building a larger home in the Central Florida (Orlando) area and would like to incorporate some green building aspects.

I've done lots of reading on ICFs but I usually only see them being compared to stick plans.
But how do they compare to "normal" concrete block construction which is usually used in Florida?

I'm interested to know what advantages to except vs using normal block in terms of strenght and insulation.
Can anyone give me a very rough idea what the price difference would be?
This is for a 2 story 2500sf downstairs, 1800sf upstairs.

Thanks!

From a thermal performance perspective, building a CMU wall and having 4" - 5" of insulation on the exterior would perform as well as (possibly better) than ICF. Strapping the interior and putting drywall would be the simplest interior finish. This may be less expensive than building with ICF (I have heard CMU gets installed for $2.00 - $3.00 per square foot including materials). With CMU option, you have the cost of CMU, insulation, interior surface prep (strapping, etc). With ICF there are no additional steps.

There is probably little difference on the non-structural performance.

With respect to structural strength. A reinforced concrete wall is typically stronger than a CMU wall with cores filled every X ft with rebar and grout. I am not sure whether this is sufficient reason to us ICF since both are designed to meet code requirements. Code designs are based on the 1/50 year wind loads or 1/100 year wind loads (I don't know exactly). An ICF wall might exceed these code requirements, but then again, you could grout fill every CMU core and be stronger than required by code as well.

WOW!!!

$ 2.00 - $ 3.00 a square foot including materials??? Here in the USA??? Do these installers have Green Cards???

My installers have green cards and the gas station wants to be paid after I fill up the truck with gas...Go figure!

Lets see. A standard CMU is 8" tall by 16" long = 128 sq. inches divided by 144 = .888 sq. ft. of wall. That block costs me about $1.40, labor is $2.00, mortar, sand, etc. pushes the cost up to about $4.00 per block or about $4.50 per sq. foot. That is for empty blocks with no reinforcing steel, no grout, etc. Nothing that would make it safe to build more that 3 feet tall. Yes, you can build cheap walls with CMUs, but when you are done, you have a CHEAP wall.

In Florida (South Florida) CMU has been mainstream for quite a while due to building codes in response to hurricane resistance, so the amount of residential walls built with CMU is much much higher than the rest of the country, therefore the subs are much more experienced and the installed rate is much cheaper - the same reason for the disparity between lumber framing and ICF. However $2 -$3 per s.f. is not quite accurate it is more in the $8 psf range (turnkey subcontract rate). This is still much lower than ICF installations wich can run between $14 and $20 psf depending on design. Granted, you still have to insulate the CMU wall. There are also upcharges for lintels in CMU walls.

Don't forget dry stacked, surface bonded concrete block.
http://www.thenaturalhome.com/drystackblock.htm
http://www.acecreteproducts.com/products/surface_bonding.pdf
http://quikcrete.net/PDFs/Projects/MortarlessBlockConstructionWithQuikwall.pdf
http://www.ourmissourilife.com/2008/07/page/2/
http://mha-net.org/msb/docs/surfbond.PDF

The cmu wall here in central fl will be $6-8 per sq ft with rebar and lintels poured. Now add furring and insulation to the interior of the wall.

The cmu wall as typically done here in FL will be about R-13 This is very inferior to ICF

We typically use 6"core ICF which far superior to a typical block wall

I have found that typically a cmu house that requires 5tons of AC, the same house in ICF will be a max of 4ton.  This reduces the cost of installation by typically a min of $1400 now add this to the cost difference of cmu and ICF, along with the reduced energy bill.

If you are going to use hardie bd you will typically fur the ext of a cmu wall,  No need to on ICF which again affects the cost dif.

Don't frame your second floor!  Do it ICF

You can't simply compare the cost of cmu installation and ICF installation, there are many factors due to the individual home.

Do we have to change the 2nd floor plan to match the downstairs bearing walls if we want to do upstairs walls in ICF as well?
What about Lite-Deck? Is this far more expensive than using a standard wood construction?

Anything done in Florida must be engineered.  Most anything can be built with ICF.  It becomes a mater of cost.  When the question of "meeting code"  ICF will always exceed standard code requirements.  When you get near the coastal wind zones and need 130 mph requirements ICF, block, and stick will become equal in cost.  But the performance of ICF will still be superior. You can apply enough "doe" to block and stick built and get close but usually close only counts with horseshoes and hand grenades.

I have some pictures of block walls blown over during hurricane Charley that had grouted cores with re-bar.  I have never seen a picture of an ICF wall blown over in a hurricane, yet. 

I will backtrack and recant. My $2.00 - $3.00 per sq ft was based on information from a "tract" home builder and is about 12 - 18 months old. I am guessing they don't have green cards. Once you are at around $8.00 per sq ft for CMU, ICF will make more sense economically (or at least be a lot closer to warrant further analysis).

If you add the cost of furring out the wall and adding insulation to equal the R-24 of the foam you have probably exceeded the 8.00 per sq. ft. cost of the block wall.  Now add the waterproofing qualities and safety to the air tight qualities of the ICF wall there is no comparison. Just the use of ICF will almost get you to a LEEDS qualified or Energy Wise Qualified building. 

The following link has some comparisons between an ICF poured wall and a comparable concrete block wall.

http://www.liteform.com/features.htm

Like most on here there is just no comparison. ICF is the way to go. By the time it is over the price will be fractional if you look at the big picture. One thing that has not been mentioned is the noise reduction and you are really creating about R 40 in the walls or better. That equals $. The over all feel of the house when complete and relaxing you will notice a big difference no kidding. I have installed many ICF systems all over the nation and the one thing that the homeowners and contractors say is that building with ICFs was the best decision they made in building there home.  

arkie6 how do you figure an 8" unreinforced cmu is comparable to a reinforced 6" cavity icf. For starters to compare apples to apples you need to get the cmu on some type of equal playing field. If you either start them out with an equal outside dimension example 12" cmu vs 6" cavity 12" outside dimension icf or take the savings of the cost of the cmu and add reinforcing to the cmu and styrofoam for insulation and or both. also if you will notice lite form is using a psi of 1200 for cmu this is the minimum allowable psi to pass astm specification, yes a cmu has to pass stringent guidlines, but anyways if you were to ask the cmu supplier for the actual test results on their cmu you will find most will triple the 1200 psi listed in lite forms website.Now lets turn this around a little. Take a 12" cmu, reinforce it with rebar and core fill like icf has then apply 2" polyiso or polystyrene sheating to each side of the cmu and now you have a far superior product strength and energy savings. these icf companys have a way of wording things to trick the unknowing into purchasing their products it is very misleading and should be outlawed!!!!!

This is the absolutely the most rediculous post i have yet to see on this forum, I think in earlier posts you have said that I have no idea what i am talking about, just look at what you just said, you are stating that a cmu wall is not safe to go over 3 feet high without reinforcing. You probably just started a pandemic!!! Now over 50% of the people in america are living in homes that are ready to collapse at any moment! Also if you check out some of the icf websites they have studies showing a 12" non reinforced cmu is equal in strength to a 6" reinforced icf , so now you would have to assume by your statement icf is not safe, also how strong would that icf be without any rebar. Why when everyone compares icf to strength of cmu do they always assume there is no reinforcing in the cmu. Everyone who has had any building experience knows what happend to concrete without reinforcing. Would you put trusses in a house without braces? Would you put roofing on a house without fasteners? Your comment yes you can build cheap walls with cmu is correct , then if you want to spend a little extra you can exceed the performance of icf , at leadt with cmu you have that option, with icf the strength is already mostly maxed out, but the cmu potential the sky is the limit!!!!

Oh god! Please, don't start answering your own posts now.

that was your first post and that is all you have to say? That really answers alot of questions. If you want to go ahead and join the bashers and not add anything intelligent to the forum than go ahead but you will be the one junking it up for everyone who wants to come on here and get real facts!!!

I apologize and will admit that up to now, I was a reader only. And will also admit that I only joined to post that reply but only after following your other posts in other threads.

If anyone would do a search on all your posts, would they categorize you as a basher or a reasonable poster? I understand that sometimes people come across as unreasonable while internally, they feel that they are communicating in a calm and reasoned manner. I am fully capable of admiting that the purpose of my post was to simply (somewhat jokingly--see funny smiley face) poke fun at you. Can you possibly, maybe drop the obtuse-ness and see that you come off just a teensy bit offensive?

Being (less than nice) is ok, but being obtuse about being (less than nice), that drives me crazy! ('less than nice' is nicer than I mean )

For example, in this posting thread...your first post is somewhat sane but the FIRST words of the second post (20 minutes later BTW) are: 'This is the absolutely the most rediculous post i have yet to see on this forum...'

So, yes. My first post and that IS all I have in me.

I'm new to all this and could really use some help. My former son-in- law built me a 2,000 sq.ft. ICF house with ISP on the roof in S.E. Ks with a crawl space. I have all brick and a metal roof. I moved in last Oct. and in April of this year I wanted to see how thing's looked under the house. I opened the crawl space to see a lake !!!!! I've been pumping water out ever since. I had a man put a sump pump outside the house but when it rain's I still have water under the house. I know this type of house doesn't have vent's but I think I need them. I'm a single lady new to the area and my former son-in-law has left me to deal with all this . Can anyone help me, PLEASE ?

Should have nothing to do with ICF. (but I might be wrong) First thing... Approach as with any house. Check that your lot is properly landscaped for drainage away from house. Install gutters if needed. What is soil like? Sounds like water is on top of slab but...it is just water. Sounds like it comes from the rain so the idea is simple. Keep water flowing away from house. -c

Mr. Schmausser,
I provided a price to you for ICF walls, as well as insulated tilt up walls. I provided this to you through your GC. I was informed that you have already chose to use a precast insulated panel for the construction of your home. I personally believe that yo are being miss informed, and are making the incorrect choice of walls system for your home. I believe that if explained truthfully to you, you would see the advantages to a cast in place concrete system, over a precast "bolt together" type system. If you would like to discuss this further, i can be reached at 239-438-2670, or at [email protected].

Good luck with your new home.

There are a lot of variable that have to be filled in to answer that question, but here's an attempt: Roughly speaking, in terms of structural strength only, used in residential, all things being the same, in terms of amount of rebar and 100% grouted CMU, a good 6" ICF will perform about the same as a good 8" cmu wall. A lot of other things to be considered for the rest of your question.

Sugar Babe,

Please start a new subject for your questions so they will stand out from the rest.  I am afraid that any help for you will be lost in the existing thread.  Believe me, you do not want to get lost in this current thread.

Have you installed ICF in the Ft. Myers area?

gms,

If you are referring to Fasano on the Ft. Myers area, the answer is yes and he is willing to travel. I am currently involved with a build the Greg and his company and believe he can really help you.

Best of luck.

Ren

Jim C,
Nice project! Was it specifically engineered? I ask because of the corners not being stacked and I have not seen any "generic" "universal" engineering cover canted corners.