ICF Home - Contractor Talk - Professional Construction and Remodeling Forum

**joasis** · 03-17-2007, 05:18 PM

Here is the ICF home we are currently building...a few pics of the start. The footing is poured, and the first picture shows the wet set of the 1st course of ICF's. The second picture is the poured first course, showing the "hooks", and the plumber is doing his rough in...the floor will be poured Monday afternoon and I will begin standing the walls Wednesday.http://www.contractortalk.com/attach...1&d=1174169870

72chevy4x4 · 03-17-2007, 07:03 PM

I hope you will continue to post progress pictures. I was looking into an ICF basement for (my future) house-the forms for about 1200sqft (30'x40') would have been about $5500. Do you have any idea if that is a reasonable price for forms?

mdshunk · 03-17-2007, 07:22 PM

Joasis... where are you getting your ICF lego's from? Local vendor? Local manufacturer? Mail order/trucked in?

Does the portion of the ICF's that are above grade just get skim coated, like Dryvit?

**joasis** · 03-17-2007, 08:04 PM

The basic block price is $15, per 16 inch by 4 foot block. These are from BUILDBLOCK...and are very similar to REWARDWALL....there are more and more manufaturers out there...the ones I would like to try next are from FoxBlock...they have a dedicated "T" block, for intersecting walls.

I am certified by Buildblock....but the cert doesn't mean a whole lot. We have a BB rep in OKC, and they deliver job site for free. I understand with FB, they will deliver free for a contractor on the first order....

The "hooks" you can see in the bottom photo are my contribution. The hooks are 4 foot long #4 bar bent with an "L" on one end and hook on the opposite...the L drops in the wet footing and turns 90 degrees and pulled up so it is under the footing rebar...leaving the hook as seen. As I stack the walls up, they get #4 bars horizontly and when I get to the 5th course, 6'-8", I will drop verticle bars with another hook and "catch" the bottom hook and tie on the horizontle bars....then place that last course for the 8 foot high wall.

The home will get brick, MD...the footing is 24 inches wide, the block centered, so I have a 6 inch ledge.

The point of the "wet set" first course is to insulate the slab, and it also form the floor forming...which explains the horizontle boards visable...so when we pour the floor, the thresholds will be over the fist course.

I will post as we go.....looks like I have 2 more of these to go, if nothing goes wrong.

**joasis** · 03-17-2007, 08:08 PM

Quote:

Originally Posted by 72chevy4x4

I hope you will continue to post progress pictures. I was looking into an ICF basement for (my future) house-the forms for about 1200sqft (30'x40') would have been about $5500. Do you have any idea if that is a reasonable price for forms?

Sounds about right.....the FoxBlock.com site has a calculator and pricing, including concrete volume...pretty neat.

The footprint of the home in the pictures is 30 X 52, + garage....2136 total...1400 inside the living area walls...which will finish 16 inches thick.

This home will have a 5/12 trussed roof, with a vaulted ceiling over the main area...2-1/2-12 reversed scissors.

thom · 03-17-2007, 09:57 PM

I don't understand the point. I've looked at several ICF projects around here and they all promote the insulative value. The standard calcs I've done show 90% of your heat loss/gain is the roof/ceiling and 90% of the loss/gain in the walls is the windows & doors. You're then dealing with 1% of the loss/gain when dealing with the opaque walls. Seems to me that if you leave that bath fart fan run an extra hour you've lost any gain for that year. Maybe it makes more sense in a less moderate climate.

concretemasonry · 03-17-2007, 10:14 PM

Most people miss the point on the value of ICF or any heavyweight construction. There is simply a real world advantage to having mass when weather is a dynamic condition from hour to hour, month to month and from season to season.

If you apply the simplistic and misleading steady state concept of R-values for lightweight materials, you get misleading results. - Like R19 insulation in a steel stud wall that is really at best a R11 to R13 wall according recognized values.

The insulation values of heavyweight construction apply on daily basis where you have temperature swings and where you have seasonal swings.

Also, with the heavier ICF and concrete masonry walls, you have no air infiltration (cracks, gaps, around penetrations) while it is a major loss in lightweight construction.

joasis - break out the candles for heating - plural because you may need 2 of them.

Dick

**joasis** · 03-17-2007, 10:30 PM

I went to Texas a few years ago and helped on a RW ICF pour...the contractor told me over dinner that evening in his own ICF home, complete with light deck roof, that his air conditioner compressor had failed a month earlier...July, 100+ everyday....and he nor his wife noticed it for 2 days....maybe a stretch...but I think the day will come if we hit $80 or higher oil, that energy efficiency will be a BIG factor in new home contruction.

I have read online about R values and ICF's....design factors, etc, and one article stated that while the form has an R20 direct value, it "acts" like an R 40...due to the mass and division of insulative properties....plus with no air movement. Add a lite deck roof with another R40 value on top...and you could heat with a candle.

The challenge it seems, is having a home too air tight...making the outside air exchangers neccessary.

My own home plans are firmed up...steel construction....but I am so impressed with ICF's, we may go for a revision.

UpIACrete · 03-17-2007, 10:39 PM

How come you used candy canes? We always used straight bar and would cut some pvc collars and slide them over the dowels to hold the vertical bars in place. Not doubting your method, just curious.

thom · 03-18-2007, 09:27 AM

Quote:

Originally Posted by concretemasonry

Also, with the heavier ICF and concrete masonry walls, you have no air infiltration (cracks, gaps, around penetrations) while it is a major loss in lightweight construction.

Don't you put wook bucks around the ICF window and door openings in order to attach windows? This would create the same situation.

As for the thermal mass, that can be produced in various ways. Around here, many of the high-end homes use adobe. While it's true that mass moderates temperature swings, making the house more comfortable, it does not reduce heat gain/loss which is primarily windows/doors/exhaust fans/roof-ceiling.

concretemasonry · 03-18-2007, 10:12 AM

joasis -

You are right about the multplier that is an attempt to predict a realistic increased R-value for heivy weight construction. A very conservative mutiplier is in many codes, but it still is short of the actual benefits and proven performance.

Many of these energy conserving facts are not promoted because the money behind the light insualting materials (mainly bulk insulation) and the representation on the codes and standards. Have you ever seen the pink panther admit to the R19 going to produce a R11 or R13 wall, even though his "creator" is a part of the standard that includes the information?

Some of the international codes and standrards are more progressive than ours, but there may be U.S. improvements in a decade or two.

No matter how much wrap, tape and goop, wood frame construction as too many leaks and falls far short of more rigid, concrete and concrete masonry homes.

At least your home under construction in the tornado belt meets the standards for tornado protection that all of the wood frame stuctures in the area do not meet the standards. - I hope the home is large enough for all the neighbors and will be completed by the start of the heavy tornado season. - Are any builder putting in "safe cells" of poured/ICF or concrete masonry in the stick built shacks?

**joasis** · 03-18-2007, 11:38 AM

This is a small custom home...and will have a 6X11 interior safe room with 6 inch concrete "cap"....master closet.

About the only reason I signed on to build this home was the opportunity to do ICF construction on a cost plus 10% basis.

I guess I march to beat of a different drummer when it comes to construction, because I love non traditional methods, and being outside the "box" so to speak.

As a note...just the traffic I have had on this job site has led to one more custom.....and possible 2 others.....so this may be good or bad...we will see.

**joasis** · 03-18-2007, 11:40 AM

Quote:

Originally Posted by UpIACrete

How come you used candy canes? We always used straight bar and would cut some pvc collars and slide them over the dowels to hold the vertical bars in place. Not doubting your method, just curious.

I didn't like the "ring" method....the hooks will allow me to pull some down tension before the walls are poured. The RW rep and BB guys are all watching to see how I do this one....I don't think I am doing anything special...but for sure, it will not slip.

**joasis** · 03-18-2007, 11:44 AM

Quote:

Originally Posted by thom

Don't you put wook bucks around the ICF window and door openings in order to attach windows? This would create the same situation.

There will be wood bucks, yes..and then it goes to how well you seal the opening. The home will have only 7 windows and 2 exterior doors....top grade thermal windows....and yes, that would definately be the weak point, as it is in any construction.

Considering all the factors, I still think this is a neat system.

vwovw · 03-19-2007, 08:26 AM

post pics of progress. I'm thinking about doing some of these. the guy from reward calls all the time trying to get me to buy.

72chevy4x4 · 03-21-2007, 09:04 AM

I have another question regarding use in as a 7 course (9' 3") basement form: do I have to pour it continous or could this be done in two pours (say half the height on day one, rest on day two)? I've read of others having problems w/ the form blowing out-is that operator error and would two pours (if it is allowable for reasons of strength) be safer.

How expensive is it to have a pump truck come in and pump the concrete?

Do you use a 3500# concrete-or something slightly different. Would fiber reinforced be a good idea for foundations to hedge the effect of settling walls?

concretemasonry · 03-21-2007, 10:09 AM

Chevy -

Forget about fibermesh in a wall - it does nothing good and is a waste of money. Slabs are a different story. It helps with micro cracks, but is not an adequate substitute for wire mesh.

You do not want anything approaching a cold joint in the wall. One of the problems with ICF construction, is that you do not have the opportunity to look at the concrete and make any repairs. Near corners and around windows are prime areas for problems (voids, bridging, honeycombing, etc.) that can lead to leakage and cracks.

Placing concrete in ICFs is really not a DIY project, so you will need to hire someone experienced to help. Some people get lucky and others have tear-out disasters.

Use good concrete placement practices and pour in smaller lifts, progressing around the basement. Repeat again and again and again, vibrating each lift into the previous lift of concrete. I would never use fly ash or any retarder in the mix since the concrete will set slower. For most sites a pump is very valuable if not absolutely necessary and is really the way to go. Just do not let the concrete get too soupy (pumpers like it that way), since blow-outs would be more possible.

Even if if it takes a little more time on the pump, you could spread out the concrete deliveries to give yourself the luxury of a slower pace on the pouring. Usually a big part of pump cost is set-up and clean-up anyway. If your trucls have pumps, then the sread out delivery time is not a problem.

In addition to blow-outs, you must be aware of the forms shifting after you have started. Brace your forms twice as well as you think you should. If you have a shift you will be stuck with with it since you cannot bring a wet wall back with flexible forms. No one wants to try to build a square home on a bowed or out of square foundation.

Follow your foam form manufacturers suggestions on the rate of pouring. There is a range of strength and stability between the form types. When selecting a system, pay attention to the technical information (details, design data, proceedures, guarantees and limitations). The quality of the technical support is much more variable than the strength and stability of the forms. Some manufacturers are just in the business because they lost the meat tray business or contract for Walmart or something like that. Avoid that type of commodity supplier!!!!

**joasis** · 03-21-2007, 06:42 PM

Here is today..we got a break on the weather and got the floor poured, finally...so the walls go up next.http://www.contractortalk.com/attach...1&d=1174520506

mdshunk · 03-21-2007, 06:45 PM

Crazy close side setback. Variance?

**joasis** · 03-21-2007, 06:46 PM

Quote:

Originally Posted by 72chevy4x4

I have another question regarding use in as a 7 course (9' 3") basement form: do I have to pour it continous or could this be done in two pours (say half the height on day one, rest on day two)? I've read of others having problems w/ the form blowing out-is that operator error and would two pours (if it is allowable for reasons of strength) be safer.

How expensive is it to have a pump truck come in and pump the concrete?

Do you use a 3500# concrete-or something slightly different. Would fiber reinforced be a good idea for foundations to hedge the effect of settling walls?

I will get a line pump to do this one, and for what you are doing, it would be about half price for a line pump as opposed to a boom pump.
Pouring slowly, as advised above, will help keep form pressure down and the risk of a blow out.

The manufacturers allow for cold joints in a bearing wall, if you have sufficient steel in place...but I would not do it...there isn't a reason to not pour it all at once.

The mix we will be using is about 4500 psi, 1/2 inch aggregate...and specific to the manufaturers specs....about $15 a yard higher here then 3000psi standard mud.