I am planing to build a 32*16 home office as a starter project using ICF blocks. I am weighing the different ICF blocks with the highest priority being ease of use and less likelihood of blowouts.
here are the pros and cons based on the information I have gathered so far:

Apex, Rastra:
pros: seem sturdier with less likelihood for blowouts, requires less concrete, easier to apply stucco and drywall
cons: heavy, more expensive, harder to run electricity and plumbing

EPS: Amvic, FoxBlocks etc..
pros: easy to run electricity and plumbing, light, cheaper, Lego blocks seem easier to lay
cons: higher chance of blowouts

Can anyone confirm if vicf (hobbs & tfsystems) have less tendency of blowouts.

Reddi-Form - also uses less concrete and might have thicker walls than others(similar to apex)

Thank you.

Texaz

Based on all the experiences discussed here the last few years I would say that propensity to blowouts is a low priority factor in considering which block to use. Blowouts are more likely caused by improper techniques in installation and concrete pouring rather than by block design.

If you're located east of the Mississippi, take a look at Polycrete Big Block. It is prove to be the largest and strongest ICF on the market. It's got a steel reinforcement inside the EPS panel so it's clearly the least likely to blow out. Not recommended for DIY, though. www.polycreteusa.com

Go with a distributor that has a local presence and is able to provide extensive training and on-site technical support/inspections. Like dmaceld said, blow-outs are most often a result of improper installation. Given that this is your first ICF project, go with an established distributor in your area. This will help ensure you have easy access to tech support, a stock supply nearby if you need additional product, and should be able to return left over product that is not used. Don't be afraid to ask for references from previous DIY customers. DO NOT look solely at bottom-line price when making your decision. You have to compare apples-to-apples to ensure quotes includes same items (ie, delivery, bracing rental, accessories, etc.)

texaz so you have a blowout, so what? I had a blowout. Guy who was the brains behind the operation called a halt. The crew stopped. He quickly grabbed a 2x4 or two. Placed the piece of styrofoam that fell off back in its place. Placed the 2x4's over the styrofoam to hold it in place. Zip zip zip with a drill/driver. Voila. Called out that the patch is done and the crew went back to work as if nothing happened.

I would suggest that instead of looking for blocks that don't blow you look for someone local who will be the brains of the operation. Chances are they're an ICF distributor. Also I would suggest looking at ease of assembly. I bought a trailer full of Reward blocks for $50 and a warehouse full of IntegraSpec blocks for $400. Then I hired someone to help. The Reward blocks wall went up in 1-2 hours. The remaining 3 IntegraSpec walls required a week to put together. To be fair the Reward wall had no windows or doors or what-not. What I saved on IntegraSpec blocks I spent on hiring labor to help me. Next time I would only buy blocks that are not very time consuming to assemble and are easy to cut. If a block folds it's not easy to cut and could be dangerous to cut. Now the real pro just assembles his walls solid (no doors or windows) and then draws his windows/doors with a marker and then cuts the windows and doors out with a sawzall. You can do that with 4" core blocks and a 10" blade. The downside is that you have to buy alot more blocks. But compared to labor these days it is worth it. My second DIY project will be done that way.

I am located in Austin, TX.

jacktca - I saw a video showing a worker building the whole wall, then making a cut for the windows and sliding in what looked to me like a roll of flexible roof flashing (for the arch), then they poured the concrete, and at the end they pulled the cut block out and were left with a window.
i think they were using either an Apex or Rastra block. I am not sure if a regular foam would be strong enough to hold.

another question I have is would it be safer for me to pour the concrete in smaller lifts, such as 2 feet at a time?

No offense meant but you are going at this backwards. If you choose a design and an energy strategy first, the block style will choose itself. Apex and Rastra result in mass exposed to the interior that can buffer daily temp swings and keep the AC off when the daily average falls in the comfort zone. If you plan to incorporate passive solar, you'll also want interior mass to buffer afternoon peak heat. Foam ICF can't react fast enough to help in either case because the interior foam wall insulates the concrete from the house. Yes, I know you are building an office, but you should be practicing with the forms better suited to your eventual house. UCLA's Climate Consultant allows you to download historical weather data for Austin and gauge how many hours a year that various strategies result in comfort without air conditioning.

As for ease of construction, in the same position as you, I chose a stacking system similar to Rastra (AAC) over conventional ICF as DIY friendlier. Granted, it's no simple task to stack a wall that's true in three dimensions, but you have all the time in the world to find mistakes and fix them. With conventional ICF, once the pumper truck wheels into the drive, you have limited time and options. If you can find an expert willing to oversee the pour, the decision changes. Such a person does not exist in my part of Pa. In either case, see if you can find a project underway wihere you can observe.

> another question I have is would it be safer for me to pour the concrete in smaller lifts, such as 2 feet at a time?

If money is no object sure.   A barrel trucks = more or less same cost as material.   So by mixing yourself  you are behind financially.  A barrel truck gives you 45 minutes of free time then charges $5/minute afterward.   Then there is the issue of a pumper.   A pumper will charge you extra if you want him to stick around and wait up for you.   Then there is the crew to consider.    During the ICF pour you are hemorrhaging money.   If you want to be safer it's a free country.  You can pay everyone around you bucks per hour or extra money to sit around and chat while you take your sweet time and be safe about it.

Also be aware that due to a phenomenon known as "cold joints" this may produce weak spots in your walls if your pours are done at a time interval which would allow the concrete to dry.   If you mean "do 2 feet, everybody take a lunch break on me, then come back, do another 2 feet", I suppose that's fine.   If you mean come back the next day or a few days later that might be too late. 

 

If your system is installed and braced correctly, there is not a reason on earth to pour it in 2' lifts. Every time you go around, concrete sticks to your webs or ties and rebar, as that builds up you create resistance to concrete flow, creating a higher chance of voids in the wall, and making it harder to get good results. To combat that issue you have to come back and vibrate the heck out of it, which will be more likely to cause a blow out than a higher pour lift.

Use a quality system with local support and trained installers or contractors. If you are unfamiliar with concrete work, you will spend less money by having someone with experience on site for a pre-pour day, and the pour day than all the money it will cost to fix mistakes. Unlike 2x4's concrete is hard to un-do...

I don't have anything nice to say about the 'waffle grid' systems or vertical ICF's, so I won't say anything at all...

Best of luck, you are at the right place for advice!

Cheers.

when using 4' lift how long should I wait before pouring the second?

thank you toddm, I did not know of about the effect on temperature when using an Apex or Rastra blocks but I will take this into consideration as Texas gets pretty hot during the summer,
which ICF did you use and how easy was it to run electricity and plumbing?

The office is a starter project for me, but I am hoping to build more complicated structures in the future and would like a product that would make it easier to scale in the future.
I am a bit concerned that as a diy it would be difficult to use products such as Apex and Rastra for a multi-story structure.

The problem with stacking systems is that cast blocks are not truly uniform and must be shimmed. It's fussy work but not impossible. Two stories aren't all that difficult. We built the second floor when we got that high, moved our limited scaffolding up onto it and kept going. Electrical is messy (in any ICF) but not all that hard either. Run two circular saw cuts an inch apart along or down the wall. Break out the gap with a hammer and chisel. It took me a bit more than a day to get ready for the electrician. But talk to your local buiilding official. The easiest way is to run outdoor (waterproof) wiring through the concrete channels in the blocks. If you have to use conduit, as I did, ask if you can run a hybrid Romex/conduit design. The fact is that most of the wiring in a house is between floors and down interior stud walls. An advantage of the composite blocks is that you can just parge stucco on one side and plaster on the other. You should be able to slap paint on it in nonpublic areas like the garage but again ask your building department.

But again, go here for Climate Consultant: http://www.energy-design-tools.aud.ucla.edu/ It's a bit tricky to download and install the weather data, but the rest is as simple as reading a recommendations page that will list the most effective energy strategies. If it says insulation, then conventional ICF is for you, and I suspect you won't have much trouble finding people to help. Good luck. Nothing better than sitting in your new home and thinking, hey, I did that.

My first floor walls had blowouts they were between 9.5' and 12'.
The concrete was 8 slump. It was like ocean. We did not use vibrator.
A small hole in the forms was resulting the all concrete blowing out.
The crew was runnung from one hole to other.

So I worked harder for 2nd floor walls.
I put extra plywoods for every connection.
It was like a patch work. The walls were only 8'.
First truck was 7 slump, second was 6".
So no bolwouts.

Enough bracing, supported openings, proper concrete slump and 4' steping result in success.

> Some misinformation here particularly about a folding block being dangerous

No misinformation, just an impartial source telling you that this is misinformation to misinform you.
The guy who claims this is misinformation also admits to being an ICF seller. So his opinion is not impartial. This guy wants to sell you as many blocks as possible.

> why would we be so popular for serious ICF work

If you read what I wrote, recap...

> ... could be dangerous to cut. Now the real pro ...

the real pro just buys more blocks than he needs and cuts holes for windows and doors with a sawzall after the wall is standing.

If you want to save money and do-it-yourself those extra blocks that you waste using this method will cost you no small amount of money. At $16-20/block do the math. If you want to avoid that very easy to build but costly way of doing things you have to cut the blocks as you assemble the wall. If that is the case then imagine trying to cut a block with a circular saw or table saw and the thing moves around and folds. texaz it's your fingers and hands and arms. I want to keep mine and so I stay away from anything that is big and bulky and folds and moves around when I'm trying to cut if I can avoid it.

Sorry Jacktca,  But having worked with dozens of installers and having been involved with several million square feet over the years I can tell you that the pros build the wall to the opening buck and never ever cut the block out afterwards.  That would silly and wastful in several ways and no serious installers that I am aware of do it.   

You would also be cutting over the wall which is a beginner mistake as well.   You don't want any foam shavings etc. in the wall cavity -- just more that you need to wash out before you pour.  

As far as the dangerous block cutting is concerned I doubt you've run a folded eight foot piece through a table saw.   You don't open the block until you've cut bloth sides and some installers even cut both sides at the same time with a band saw -- (again, block is not open yet).

Hey texaz, TexasICF knows what he's talking about. Jacktca is a troll and a moron with some sort of axe to grind. He knows the price of everything and the value of nothing. Ignore him.

> the pros build the wall to the opening buck and never ever cut the block out afterwards

> You don't open the block until you've cut bloth sides and some installers even cut both sides at the same time

Wait! You just said never ever cut the block. Then you go on to explain how to cut the block.

If I am understanding you correctly you are saying that the pro knows where to cut before he stacks and assembles the block, correct? OK, I respect that opinion. What I have difficulty understanding is how you can cut a block that folds easily on both sides or with the band saw. I think it's rather you saying that it's easy because you have some affinity to work with some specific block manufacturer that you like or represent. An impartial independent third party will say forget trying to cut blocks that fold or move around.

Jack, You rip it (folded) on a table saw. To cross cut, you just stick a 2x6 (or whatever) inside to hold it open and cut one side at a time with a circular saw or a demo saw (depends how good you are with a saw). If you don't know how to use a saw, you oughtn't to be doing this in the first place.

Posted By TexasICF on 22 Nov 2012 03:05 PM
Sorry Jacktca,  But having worked with dozens of installers and having been involved with several million square feet over the years I can tell you that the pros build the wall to the opening buck and never ever cut the block out afterwards.  That would silly and wastful in several ways and no serious installers that I am aware of do it.   

You would also be cutting over the wall which is a beginner mistake as well.   You don't want any foam shavings etc. in the wall cavity -- just more that you need to wash out before you pour.  

As far as the dangerous block cutting is concerned I doubt you've run a folded eight foot piece through a table saw.   You don't open the block until you've cut bloth sides and some installers even cut both sides at the same time with a band saw -- (again, block is not open yet).

Well said. Any ICF installer that would cut out the window or door with a SawZall after they stacked is an ICF installer you need to run far away from. Folding blocks like Nudura are not difficult to cut except for those with little to no experience with ICF.

I used Nudura. I tried to cut some parts after installing.

1 - I found that it not easy to cut stright with a Makita recip saw.
2 - How they are cuting the other side of ICF when installing 2nd floor.
3 - The hardest part is not to cut the ICF, Installing the wood supports is the hard part..
4 - I used a big hand saw before installing. It is easy to cut stright with a big saw.
5 - I used table saw when I need to cut webs. (a cheap thick blade is the best, expensive thin blades are throwing the form forward.)