Sunday, November 4, 2012

ICF forms are poured

Pump showed up at 8:30.  Concrete showed up at 9.  We had a good size crew there comprised of newbs, experienced ICFers, and the man himself, Andrew Hobbs.
However we were still scrambling to finish up last minute things.  The concrete had to sit there for about 20 minutes before we could start to pump it.
The specs called for a 3000lb, 3/8" ship mix at a 4 slump, then we would adjust it on site.  We started with the garage forms, and it went pretty well.  Moved over to the basement walls, and it was getting hung up on the rebar and forms inside.  We adjusted it to about a 5 slump and everything flowed great.  It took a little bit of practice on the pumper to control it well (ok, took about the entire basement pour to finally get the hang of it) but everything turned out well.  A little more sloppy and messy than I would have liked, but it all still works. 
All in all, the stressful day went on without any issue, no blow outs, no problems really of any kind.  However I am not sure if I am looking forward to it on the next level in a few weeks...

I am admiring our work from the mountain tops

Pumper truck getting started

Pouring the garage forms

first round around the basement forms.  We went around this 3 times with lifts of roughly 3-4' each.

Me and my younger brother moving the vibrator.  That large hole is for the HRV fresh air intake and exhaust.  All of the holes for the hvac and plumbing items are stubbed through the wall with pvc so we do not have to drill later.  Besides, not sure if they make a drill bit that big anyway....

Forms completed.  One level down, lots of work to go.
This week we will get the plastic and that pretty pink foam down down on the rock floor.  Hopefully pour the basement slab this Saturday weather permitting.

Rebar is continuous from the bottom of the form to out the top roughly 6".  I will install a horizontal #5 around the top at about 3" up for the main level forms.

Garage forms all finished


  1. Hi Jesse-

    Nice blog and even better house. This spring I'm doing a Hobbs walkout basement. I don't think the owner is coming to help and I can't afford any mis-steps. Can you share your tips for being successful (no blow-outs, straight, level, and plumb walls)?

    I tried joining you site to email you but couldn't find an address. HOpefully you can find mine through your "followers" list.

  2. Peter
    the trick is to prep everything and make sure you double check the list. Andy can provide you a prepour check list that is helpful in making sure everything is taken care of. Bracing and preparation is helpful. Do not underestimate the power of the walers and corner bracing. As I found out, these make a huge difference. Get the walers up, screw to everything and level/plumb as you go. Once that is done, and braced up, your forms wont move. Mine was not perfect, and I actually had more issues on the main level than the lower, but that was due to my fault. I did have a couple blow outs on the main level due to the foam not being tight in the plastic. The basement I had them tight, and a couple places they were just loose enough to pop out under the weight of concrete. This, however, is a major pro to Hobbs. We were able to slide the foam out and slide a new one in...with concrete in it. Took us a few minutes to do during the pour and you will never know it ever happened.

  3. Hi Jesse-

    Thanks for your response. I hadn't checked back here in a long time. Just finished my Hobbs basement wall pour yesterday. Things went well. Our bracing was up to the task. Nothing moved, no blow-outs. The system seems really robust. We did have a couple issues. Firstly, we didn't have enough scaffold/planking to walk all the way around the inside without moving it. That was a mistake. There are lots of things going on and people end up scattered all along the way. I like the bracing you did and should have insisted on doing it that way. Instead we had to have people dedicated to moving the walk planks/scaffold instead of something more useful. The second was dealing with a non-level top of wall. This may well have been the footing but we didn't check anything until we to to the top of the forms. Which made some sense because the footing weren't going to change now. We had nearly an inch from one corner of the house all the way to the other. We tried marking this along the top of the wall and cutting the foam before pouring but that didn't go so well. We're better now than we were but still out so I need to figure out how to fix that before moving upward.

    Our mix was 4000 psi 4-5" slump and it flowed pretty well. Did vibration do much on your walls?