Posted By Calamityj on 21 May 2014 02:54 PM
We used 8" Logix and Amvic for our projects. The engineer called for the #5 Rebar both directions. We also added two 4'x8'x12' long deadmen for reinforcement on an 80' long wall that is 17' tall INGROUND....In a more conventional plan, you could most likely use #4 rebar.... This structure is 40x80 and has an offset gable with a 26' rise. We incorporated an enormous Lam Beam that is 6.5"x20"Hx80'Length....also engineered roof system with R55+ and dead air space of 4" under a standing rib metal roof, to accomodate a fan operated on a thermostat concealed in a large cupola.

Please NOTE: Logix blocks are great, but not Unisex.... therefore, you could have a little more waste than with other blocks such as Amvic/Build Block/Nudura/Quad0lock or other unisex products.... reason, they can go both ways for stacking.

I believe the above answers the below question posed by Robinnc. With 8" walls and all that heavy duty reinforcement your home required, I can see how it would cost 20-30% more than a wood frame home. With that being said, your home is not the "standard" ICF home and would be the exception to the rule. Most ICF homes require 6" walls (some can do 4") and a lot less reinforcement so the costs are considerably lower.

Post or link some pics so we can see this home. Hard to imagine what it looks like just based on the comments...

Posted By robinnc on 20 May 2014 11:13 PM
Cal.....where do you come up with 20-30% higher cost? Everything I've read over the years it's not even close to that much.

I will try to get some pics posted soon....

I know what it costs to build a house. I'm asking anyone about the s/f cost of the 'wall' of a stick built house. ICF is quoted by s/f range in $10-15. Just wondering if anyone has a ballpark price for stick built.

a typical 2x6 wall, single bottom plate, double top plate, 92 5/8" pre-cut studs, 7/16" OSB, 2x10 headers, R20 pink fiberglass, super 6 poly, tyvek exterior - $ 5.00-6.00 sq.ft.

Posted By robinnc on 21 May 2014 07:28 PM
I know what it costs to build a house. I'm asking anyone about the s/f cost of the 'wall' of a stick built house. ICF is quoted by s/f range in $10-15. Just wondering if anyone has a ballpark price for stick built.

Stick frame homes are not calculated that way so getting a figure is difficult. Too many variables involved in a stick frame home:

• 2x4, 2x6, or double stud
• fiberglass, cellulose, spray foam open or closed, polyiso, polyurethane, EPS, roxul batts, interior wall insulation choices
  
• Roxul, EPS, XPS, or no exterior wall insulation
• vapor & air barriers; Tyvek, tar paper, peel & stick, etc
  

With ICF you don't have all these variables so it's easier to calculate the wall square footage. You basically have the forms, rebar and concrete. ICF is more of a "packaged" system.

It's also not an apples to apples comparison. With stick framed homes, they are not as strong as an ICF home. Put up a 2x6 & OSB sheathed wall against a 6" reinforced concrete wall, no contest.

So a house with 5000 sq.ft. of wall, and just comparing the walls only is ranging from 20-45k more with ICF only

Average house I do is 1.2m, so increased cost is 3.75% overall.

Chances are when it's all said and done, increase cost is 10-15% based on better selections, not just ICF, but radiant heat, better windows, spray foam attic, etc, etc, etc

Thanks Chris, that's what I was looking for.

Lbear.....there is no question that ICF walls are superior over stick.

Hey there,

Originally from Europe I've over 15 years experience with ICF's and have used 10+ brands - all of which have their individual strong points and weak points. I'm not going to go into the advantages of ICF over Stick - suffice to say that in Europe where we are surrounded with structures built 100's and 1000's of years ago and still in daily use, they are mostly built with solid masonry and the downside is usually insulation - or lack of it. ICF solves this - and if you choose an ICF with offset insulation to the exterior of the wall you get a building that makes best use of the thermal mass of the concrete too.

To come back to the question, as far as cost goes what I've found is that an experienced ICF crew can get the construction cost of a finished house down to about the same price of Stick - and that's without considering all the cost savings an ICF owner/user makes - Cheaper heating / cooling / insurance + Increased home value + Increased security + Comfort + Sound insulation etc. etc.

So that's what my experienced view is - seek out a highly experienced team to help and you are on a winner.

It's also often worth looking into an ICF form for Floor Slabs and Footings - some systems for basements also allow for a monolithic pour which sure keeps everything solid and water resistant.

Last but not least - since Helix Steel micro rebar got vertical wall approval http://goo.gl/7az9US if in a suitable area its worth doing a cost comparison based on both the time/labor saving of rebar placement and the actual materials cost saving.

As you mention Florida - I worked recently with an engineer in Florida who has specific concrete and ICF experience - and Sam helped the project overall make significant savings through experience, contacts and common sense - I'm happy to recommend him - Samuel N. Barresi, BS CE http://goo.gl/F5K3Nh

Should have mentioned too - on the project for a simple but robust 2500 sq ft home in Florida that can take a storm and be very energy efficient, we used Geo-Slab for the footings, BuildBlock's GlobalBlock and the Helix for the walls, Metaldeck and suspended drywall for intermediate floors and BuildDeck for the roof and we got overall cost to less than Stick due to time savings and concrete reduction. I know the all foam GlobalBlocks aren't ideal for every application - but by taking some care to extra brace corners we had no issues.

Have a great build and enjoy your ICF home - if you have any questions i'm happy to respond.

30years under the belt
if your icf cost numbers are what you say, i have lots of work for you.
contact me at 772 225 5404
or insuldeckflorida at aol dot com
peter

It would be impossible to build ICF in total for the same cost as stick-built...without slave labor. We built ours and still paid some labor. IF we had hired a GC, and his crew, we would have added another 80-100K to our project. We carefully contained costs and built a 4,000 SQ FT. upscale Rustic Industrial inground, all ICF to the gable ends 30' in the air, with two 4'x12' deadmen for under $300,000 USD. It almost killed us, AND, we lived in a horsebarn tackroom for a year and a half.... It is nothing short of amazing every day. Constant temp maintained at 68* floor to ceiling.

I tried to download photos but could not seem to get them to.

BB's Global block is less money than the standard block and because it is a screen grid, uses less concrete.

Hi all, l-o-n-g time lurker, first time poster. It's great to find some current pricing (ballpark of course) on ICF's as I'm currently looking into building an ICF home in NH. I'm particularly interested in concrete floor system pricing. I've only just begun researching concrete decks so I've got a way to go, but some great info here. Thanks all!

A while back there was a discussion about concrete deck pricing. I think it was said that total with labor was around $25/ft2. We did our 1st floor and roof last year using 12.5" quad deck forms $5.60/ft2- came out to $13.60/ft2 we did all the labor. Both were spanning 30ft. rebar was pretty heavy, also included Vl-2020 (sealer) in all the concrete to get rid of moisture.

Who's block are you using for that price and how does it compare to others? At this point my interest is in Amvic or BuildBlock. Also, do you do any radiant concrete floors and if so do you still use ash in the concrete and how much? How would the ash affect the slab with the heating?

Don't use high fly ash content for floors. It finishes terribly

Does it matter if the floors are going to be covered? Probably with engineered wood flooring.

Can you describe the terrible finish? I assume that working the concrete was ok. What percentage of the mix was the fly ash.

35%. If you work the floor in a regular manner the floor when it is dry will be powdery not hard like a usual floor.

Interesting that you would have a powdery finish on the concrete. As a rule, this is the result of recombining weep waters into the floor, that is getting on the slab to soon with the power trowel. Fly ash can slow down the kick over time of the concrete so a finisher may not have waited long enough for the weep waters to rise and then rehydrate. Also fly ash mixes may not need as much water as non fly ash mixes, so there might have been more water added then needed.

Because concrete is never the same twice, it can be really hard to say just why your floor would have gone soft but it is something I have not experienced when using fly ash mixes.