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ICF cost (post #81696)

Can anyone give me a general formula for estimating the cost of ICF?  Somewhere I saw $10/sq ft of wall space as a reasonable estimate when trying to decide which type of foundation to go with.  That figure included the cost of the block, steel, concrete and labor as a general guideline.  Does that sound reasonable?  We are in California and I'm wondering if it may be more.  Since our house plans aren't finished yet, we can't go after firm bids for it yet and I don't want to wastes time having the foundation drawings geared towards ICF if it's cost prohibitive.  Your experience?


Edited 3/15/2008 4:27 pm ET by ptmckiou

(post #81696, reply #1 of 98)

I was told just the material no concrete is $30 a block, but with a 300 mph rated wind speed, I would care how much it cost

(post #81696, reply #2 of 98)

There are different types of ICF blocks and I assume that they have different costs. Most are the polystyrene with various types of connectors between the inside and outside wall. However, there are also types of ICF blocks that are more like a lightweight concrete block that incorporate cement and either wood chips or polystyrene beads to provide an ICF that has much more inherent strength before the concrete is poured into it than does the polystyrene ICF. This type of ICF is supposedly more fire and insect resistant than the regular polystyrene based ICF.

There is also a type of polystyrene ICF that incorporates boric acid to keep the little creepy crawlies from partying in the plastic... I assume this comes as an extra cost item. Shipping may not be insignificant on ICFs, particularly if you want the boric acid treated ICFs in N. Calif. and they are only manufactured in Georgia.

A couple of years ago, I priced out the cement and wood chip ICFs and the price then was about $5.00 per square foot of wall area - rebar, concrete, and freight extra. I think this was for Faswall ICFs, but I think Rastra was similar. This may not have included the extra insulation that can be stuffed into the cavaties of this type of ICF to give it a reasonable R value.

(post #81696, reply #3 of 98)

Fox Blocks has their block prices posted and they are under $3.00 per block.  Most people I've talked to say the majority of ICF blocks are $2.75 to $3.25 per block (and they are hurricane proof).  Most block forms are 16" x 48" but they do vary some. That's why I wanted a sf price.  My 2008 National Construction Estimator calculates the block, steel, concrete and labor at $6.01 SF and that seems low to me.

(post #81696, reply #4 of 98)

ptmckiou


My 2008 Construction Estimator comes up with a price of 11.78/SF. That's ICF forms, rebar, concrete, labor and tax. No markup.


Rich 

(post #81696, reply #6 of 98)

Wow, that's cheap. We pay about 19 bucks for a 8x16X48 logix.

(post #81696, reply #47 of 98)

Closer to 25 here. I'm thinking he got his decimal misplaced

 

 


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(post #81696, reply #5 of 98)

Are you doing the whole house to plate line or just a basement area?

(post #81696, reply #7 of 98)

I had ICFs used for my "dream" house.  It produced the warmest, driest basement I've ever seen.  I would not hesitate to use them again.


As for estimating the price, get a price per block from the supplier and the price per yard for concrete and do the math.

(post #81696, reply #8 of 98)

I'd be interested in a comparison of the Mooney Wall system as employed by Mike Smith and ICFs, both on cost/sqft and energy efficiency. 


I'm posting this to Mike in hopes that he'll take the time to discuss it with us.

(post #81696, reply #9 of 98)

i'm home... and my mooney data is down at the office.. maybe tomorrow

Mike Smith Rhode Island : Design / Build / Repair / Restore

Mike Smith Rhode Island : Design / Build / Repair / Restore

              www.mfsmithbuilder.com

(post #81696, reply #10 of 98)

Mike,


I wager that, coming from you, such a comparison would be a valuable resource. 


I'll be building several homes which will use some type of super-insulated system so I'd certainly be grateful to have your help in estimating costs and long term value.


I'd suggest that you begin a new thread so that the topic isn't missed by the many people who are or will be considering the same questions.


Thanks, Peter

(post #81696, reply #11 of 98)

I just had a local California contractor email me a general line of cost .....


$4 Block &  materials


$1 rebar


$3 concrete, concrete pump & bracing system


$8 labor


=====


$16/sq foot  OUCH!  Thaaaaaat is cost prohibitive for us to go all the way to the eaves.  Looks like just the basement is going to be ICF.

(post #81696, reply #13 of 98)

ptmckiou


 $8.00 labor?   per sq.ft?  Do they arrive via private jet and  wear Armani suits while working?   

(post #81696, reply #15 of 98)

May I suggest that you peruse the www.arxxwalls.com web site, checking for videos on the installation of the forms.  I watched one on there which showed how fast and easy the blocks are to install, including cutting with a small hand saw. 


ICFs are probably the most DIY friendly building material to come along in my lifetime.  If you're serious about saving money, you should be willing to get involved in the building process.  Take a training seminar or go visit a jobsite and watch how it's done.  If you do that you'll be in a position to practically eliminate the labor portion of the equation.


At least take the time to contact several ICF manufacturers.  They have trained sales people who will happily return your call, ask a few simple questions, then send you a DVD which shows all the steps involved in building with ICFs.  I have several such DVDs on my desk. 


I'm not yet convinced that ICFs are the best solution for someone with my knowledge and skills but it's easy to see that they will soon become a much larger part of the DIY market. 


 

(post #81696, reply #16 of 98)

I've viewed the videos.  It certainly looks DIY friendly and I know I could to it -  but I work 16 hour days 5 days a  week now, so I have to hire out the job.  Unfortunately, doing it myself is not an option.  If I could find the time off... it would be a no brainer.

(post #81696, reply #17 of 98)

I recently heard of a new system (I think by dow/corning) in which the insulation is put in the middle of the form.

This is to resolve moisture issues that have been found in icf's.

Something to look at and may be less expensive.

(post #81696, reply #18 of 98)

I recently heard of a new system (I think by dow/corning) in which the insulation is put in the middle of the form.


This is to resolve moisture issues that have been found in icf's.


Something to look at and may be less expensive.


What "moisture issues"? 


None of your speculation is useful without a link to a verifiable source, as a reference. 


 

(post #81696, reply #19 of 98)

I also am looking at a project that requires ICF.
4000sq/ft. building.

Completed Costs from others projects for the ICF portion would be nice to know


They can't get your Goat if you don't tell them where it is hidden.

Life is Good

(post #81696, reply #20 of 98)

Here is a link to what I mentioned for the process although it says nothing about the moisture I was talking about.

http://building.dow.com/styrofoam/media/news/backgrounders/styrofoamtmass.htm

(post #81696, reply #22 of 98)

Jebedia,


That's a good discussion, on that linked site.  Thanks for posting it here.


Peter

(post #81696, reply #28 of 98)

It appears to me that this is a precast slab that you would get from a concrete plant that had the equipment, not a form that would be used on site such as the usual ICFs. Just trying to clarify, I am not knocking the product. I have yet to find a good technical description of it, however.

(post #81696, reply #29 of 98)

To My understanding it is not precast or should I say it can be poured on site. There is rebar in the insulation already. This was a discussion at a continuing education class.

I am not completely sure about the product as I have not researched it at all.

I was merely putting it out there.

(post #81696, reply #27 of 98)

Not sure how a "Moisture Issue" can be caused by a ICF block wall.  The only way that can happen is to have poor circulation and that problem is endemic in any very tight homes. 


That is why it is so important to involve a HRV or HVAC designer before the first block is ever laid. The same is said for SIP construction. 


 YOU MUST HAVE PROPER VENTALTILATION  in any home where you don't have air infiltration problems. 


Stick built homes with F/G insulation and little no or improper moisture barrier will not see this problem because of the permeability of the walls.  Hence you are (attempting)to heat the outdoors.

(post #81696, reply #30 of 98)

Talisker2,

I apologize for not knowing the specifics.

It was brought up in an continuing ed class I recently took and I don't remember the whole discussion.

I will however see If I can find out more though.

(post #81696, reply #31 of 98)

Jeb, not a problem.  It is a misconception among many people that believe that a house can be built "too tight".  In the days of cheap energy it was common practice to build with a expected amount of air moving through the house.  I did back in the 70's and now I am paying for it.  I have a laundry list of things I must do before I can even request a preliminary energy audit.  I know I have a leaky house and have the gas bills to prove it.<G>


But now I have the knowledge to fix as much as I can without a major expense.


Jim

(post #81696, reply #34 of 98)

From what I remember of the discussion there is a certain amount of moisture released from concrete and by putting the insulation between the concrete it is supposed to help it from gathering mold?

Like I said I will have to get a hold of the instructor to find out what it was we were discussing exactly.

The instructor is a contractor himself teaching the con. ed. 1-2 days a month. He is rather informative.

(post #81696, reply #37 of 98)

jebadia,


 OH I think I understand the issue. concrete releases moisture as it cures..  to prevent this from being an issue they require  decay resistant wood as a top plate. Insulated as it is the moisture is released slower producing less stress in drying making the concrete strnger than it's rating..  but there are a lot of materials in a house that a releasing moisture at the same time..


  The wood a house is built with for exapmple is usually stamped something like  KD 19  which means Kiln dried to 19% moisture plus or minus 2%.  normal moisture in those 2x4's is around 5 to 7% once completely dried..  add the water for the concrete and the moisture from wood and the average house is extremely damp the first tear.. damp means mold potential..  

(post #81696, reply #48 of 98)

"which means Kiln dried to 19% moisture plus or minus 2%. normal moisture in those 2x4's is around 5 to 7% once completely dried.."

Try that again. Maybe 7% dried in Tucson...10-12% elsewhere.

The KD is surface dried to 19% so inside the lumber can still be much wetter. overall you point is right here, but you really gotta quit making up the specifics on the fly like that unless you want us to call you the poet so you can employ that poetic license...

;)

 

 


Welcome to the
Taunton University of
Knowledge FHB Campus at Breaktime.
 where ...
Excellence is its own reward!

 

 

Oh Well,

We did the best we could...

(post #81696, reply #50 of 98)

piffin,


 Ah!  Now I got you!  You just split hairs and I'll split them finer..


  Your numbers aren't valid in houses heated in the winter unless they are pumping moisture into the air..


 So yes I'll grant your numbers might be valid in the summer but not in the winter.


  The thrust of my comment was correct as you kindly pointed out..

(post #81696, reply #32 of 98)

Jebadia


 If there were a moisture problem with ICF's I'd know about it.. six years ago I put my first wall of ICF's and sheetrocked it.. Moisture sure would have ruined it by now..


  No I'm afraid if you understood ICF's that issue wouldn't have come up.  While it is true that you need to waterproof the outside simply because under enough water pressure water can be forced thru the seams in the block,  thru the concrete, and thru the inside foam. 


  But you need to waterproof cement block, you need to waterproof poured concrete, or any other type of foundation..