I had lots of questions from my post on Tuesday, so I thought I’d answer them in a post so others can find the answers quicker.
what material is used to hold back the concrete for the ceiling itself? steel? foam? could you do the job with “pre stressed” concrete precast panels?
when you pour the side walls, how high can you go in one pour, without additional bracing around the ICFs?
The ceiling was held up for the pour by plywood and insulation panels. Once dry, the plywood (and 2×4 bracings) were taken away, and the insulation panels were left up. I can’t remember if those panels were just painted with ceiling paint, or whether we did some ceiling drywall.
I know nothing about pre-stressed concrete precast panels. I would say you’d need to refer to engineering specs for the panels, and compare those specs to what you need in terms of spans between support and weight bearing requirements.
Side walls, experienced crews with top of the line equipment can go 14 feet in one pour with minimal bracing. Regional crews without all the fancy (expensive) gear can pour an 8-10 foot wall in one pour, no problem. (Or they should, be wary if yours can’t.) The bracing required for a wall is shown to the right. If you are doing a multistory house, pour the walls, then install the flooring, and then begin the process again.
child of Odin
As always, this is my favorite blog. … First, do you have pics of the finished product? My wife is not a prepper, and not interested in “alternative” building techniques unless thy look normal. Pics could help convince her. Second question: how does this compare, price wise, with conventional building methods? Third: you use a crew, but how DIY friendly is it.
Glad to hear we’re your favorite!
I don’t have public pics of the doomstead. I’m a little paranoid about how easy it can be to use images on the web to find places/people. Plus, I don’t know if I’d call it finished. It’s getting a lot closer, and there have been people living in it for a couple of years now, but it’s definitely still a work in progress.
ICF houses can look like hobbit holes, or they can look like mansions. It all depends on how they are designed. I wouldn’t try to DIY one of the mansion ones, but hobbit holes are very friendly for non-professionals. Check out this picture from the company we used for materials. Quad-lock.
They still need to put on some exterior finishing, like a siding or brick, but it has windows and doors and when finished will likely look like any other nice home.
Most builders put building costs at 6-8% above conventional building.
On one hand it’s very DIY friendly. It’s easy to design with, and the forms are easy to put together. But, you have to be careful about the pouring; between bracing, vibrating out bubbles and slowing the pour from the pump truck, it can be intimidating if you are a complete novice.
What’s the Ballistic Protection profile like? For example will it stop sustained .50 BMG fire from a crew-served weapon? Or is it designed to only stop sustained .30-06 fire from a shoulder-fired weapon? If the protection profile is there, then it would be the ideal barrier material for exterior walls in a residential structure, especially if said structure was located either semi or completely encased in a hill-side or underground. Of course that leads to the question about overhead protection against indirect fire weapons such as the universal 155mm howitzer round.
KC, wow man. Those are some important questions. We certainly have felt at times like firing ammunition at the doomstead-in-progress. However, we haven’t actually gotten around to doing that. And since I don’t think I know anyone with access to a .50 or a howitzer, I’m not sure I’ll ever have an answer for you on those. I do know that we used the 6 inch molds, so ammunition would have to get through 6 inches of concrete and rebar, plus the 2-5 feet of dirt and rocks used in the berms. Or it would have to go through a window. :-D We put windows in, since we like our sunshine and we like the pretty bit of land the doomstead is on.
http://www.icfbasement.org/ <– They have some great project pics.
http://www.icfmag.com/index.html <– There is an ICF magazine, for all your ICF reading needs. :-)
Spray foam is your friend!
Don’t forget to leave openings for your HVAC, electricity, telecommunications and plumbing. :-D
Thanks for all the questions! Hope these answers shed some light.
- Calamity Jane