New Idea For ICF Stem Wall / Footer Foundation
Last Post 18 Nov 2008 12:50 AM by tlynch. 17 Replies.
Printer Friendly
Sort:
PrevPrev NextNext
You are not authorized to post a reply.
Author Messages
tlynchUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:105

--
05 Nov 2008 05:09 PM
I have searched the web and I have not found anything like what I am thinking about, but I thought it might be a cost efficient system for building an insulated stem wall / and footer foundation. It would be a set of plastic pieces that would allow you to create your foundation form work out of standard 4x8 pieces of foam. The plastic pieces would hold the foam in place, along with plastic ties that would pierce through both pieces of foam and hold the two sides from spreading apart. The holes in the plastic pieces would provide places to rest the rebar. The plastic footing forms for the footings (not shown) would have channels in the top where the foam sheets would fit snugly. The stem wall and the footings could be poured in one pour. You might have to backfill before the pour. Thoughts?

Attachment: basic.jpg
Attachment: wireframe.jpg

tlynchUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:105

--
05 Nov 2008 05:14 PM
This would be used for slab foundations with stem walls.


AltonUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:1974

--
05 Nov 2008 08:03 PM

Tlynch,

Royal Building Technologies has a system called Royal Building Systems that can consist of a double-wall vinyl form filled with concrete and polyurethane foam.  This system can be used for above and below grade applications.  My experience with this system is limited to one home, but I did find it very easy to use.



Residential Designer & Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu, 334 826-3979
tlynchUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:105

--
05 Nov 2008 10:09 PM
I just took a look at that system. It is along the lines of my idea.

Mine would only be for below grade applications - with a max 4' wall height - and the plastic would not completely encapsulate the foam, just provide the minimum support to hold it in place during the poor.

The goal would be to create a system that standard foundation contractors, who are used to working with steel or wood forms, could easily set up in the same or less amount of time, and the forms would not have to be removed or washed. That labor cost savings would cover the cost of the additional insulation and the plastic ties, spacers and connectors, and plastic footing molds. The cost of the plastic footing molds could be saved by allowing for a single pour.

Pushing a plastic tie through both materials and slipping a self locking washer over the far side could be done very quickly by a team of two, faster than the steel ties used with a wood form. Even if more are required.

Any engineers have an idea of how many plastic ties would be needed to hold two sheets of EPS foam in place for a 4' wall pour? Is it realistic?









tlynchUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:105

--
05 Nov 2008 10:13 PM
Or maybe re-usable steel shaped U's that are slipped over the top of the forms, and slide right off when you are done. Bracing could attach to these steel U's.

There could be a plastic tie that is inserted at the bottom of the U holding the two loose ends of the U together.


tlynchUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:105

--
05 Nov 2008 11:04 PM
An 8x4', 2" thick EPS board is $20 per board. 2 boards = $40. For 32 square feet. $1.25 a square foot.

You would need one end connector per section, which might cost $5 each and 4 spacer which might also cost $5 each, and 32 plastic ties at $.20 each, so that would be another $30 a section. This puts you at roughly $2 a square foot.

Shipping would be far less than ICF's.

The cheapest ICF is roughly $3.25 a square foot.

For someone pouring a slab on grade with stem walls, cost saving is obviously key, and this might serve that purpose well.






ErgoDeskUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:149

--
07 Nov 2008 08:44 PM

The construction industry is changing fast, I just posted on the Sip's Forum but it is relevant here. This System uses EPS Foam from in the ground to the roof and coated with concrete to become fire proof.

Link: http://greenbuildingtalk.com/Forums/tabid/53/forumid/5/postid/44971/view/topic/Default.aspx



Build Smarter with Structural Insulated Air
http://StyroHomeNews.blogspot.com
rgbUser is Offline
New Member
New Member
Send Private Message
Posts:21

--
08 Nov 2008 06:22 PM
tlynch

I'm a greenhorn on this site, so if I miss the etiquette, please excuse me.

I think you might be onto something here with a bit more work.

The difficulties I see are in things like fishing the rebar through the holes in the internal supports once the form has been assembled to a height of four feet, dealing with angles including 90's, especially with the extra reinforcing there and, once you've ironed out some wrinkles, marketing such a specialized product.

rgb


tlynchUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:105

--
09 Nov 2008 02:51 PM
I sent an email to Sonotube about my idea because I think they would be in a position to market it. Their tubes and footings are an industry standard from what I understand. Their square footings could be elongated to make the forms for the footing. The top of the footing forms would have two channels spaced 8" apart that would accept the base of the EPS. The channel would be deep enough to keep the bottom of the forms from blowing out.

I realized that the forms only have to be held apart until the pour starts, at that point, the only force needed is to keep the EPS from bursting. I think the inverted U's could have 1" spikes that bite into the foam keeping it in place until the pour starts. I think You would need one inverted steel U every 12"-18". This would allow you to easily place rebar inside. The rebar could be supported by plastic rods pushed through the foam.

I think the H channel that holds the ends of the foam together would not have to be that big and could be cheaply extruded. A U channel could go over the top edge of the foam to hold the butt ends in proper alignment.

1" wide Nylon straps could attach to the top of the U's and could be used as guy lines with tent stakes to hold the form in place.

1" Nylon


smartwallUser is Offline
Advanced Member
Advanced Member
Send Private Message
Posts:575
Avatar

--
12 Nov 2008 08:03 AM
There are already a number of systems to mono-pour stem walls and full height walls.


arkie6User is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:1067

--
12 Nov 2008 11:31 AM
This looks like a complicated solution compared to systems that already exist. Lite-Form for instance makes an 8"x8'x2" XPS flat plank with slots cut every 8" along the edge. Plastic ties (length varies depending on desired concrete width) are then inserted in these slots to hold the panels together and support horizontal rebar as required. They also have friction fit metal in-wall bracing to hold the forms straight. To use this in a footing/stem wall mono-pour just requires some method to support the foam over the footing forms. I've seen drop ceiling metal "T" rail supports cut to span across the footing forms and used for this purpose.

Lite-Form also makes plastic ties that have heads that can be sheared off so the foam panels can be removed and reused if desired.


tlynchUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:105

--
12 Nov 2008 03:17 PM
Thanks arkie6, that system is right along the lines of what I was thinking about. I would like larger generic panels to reduce cost, but that system would work.

Footing forms that have channels to hold the first course of foam would complete the system perfectly.


tlynchUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:105

--
13 Nov 2008 08:22 PM
All you are missing is the footer form, like the attached image... And the ability to use stock EPS board!

Attachment: footerform.gif

arkie6User is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:1067

--
14 Nov 2008 10:16 AM
Posted By tlynch on 11/12/2008 3:17 PM
Thanks arkie6, that system is right along the lines of what I was thinking about. I would like larger generic panels to reduce cost, but that system would work.

Footing forms that have channels to hold the first course of foam would complete the system perfectly.
I'm not sure how much you could actually save, but you could buy your own 2" x 4' x 8' sheets of XPS and cut them to the desired width and then cut the 1" deep notches every 8" OC yourself.  Then just buy the ties from a Lite-Form dealer or directly from Lite-Form.   This stuff is easily cut with a 10" abrasive saw blade in a table saw.

If you were not going more than 4' high, you could probably get away with 12" high planks of XPS instead of 8".  That would save a few cuts and a few ties.

For the footing attachement, if you were using something like say Fab-Form FastFoot attached to staked 2x4s, you could use the drop ceiling metal support grid  "T"s cut ~6" wider than your footing top width, then take a grinder with a cut-off wheel or tin snips and cut through the bottom leg of the "T" at the inside edge of the footing boards, then make another cut at the outside edge of the footing boards.  Now fold this ~1-1/2" leg section over until it is flat with the top of the "T".  Now place this over your footing forms and screw to the top of the forms.  This will serve two purposes: 1) hold the stem wall forms up, and 2) hold the footing forms at the desired width during the pour.   Repeat every 2' or so.  Now place your first course of Lite-Form panels over the "T"s and align such that the bottom ties in the Lite-Form panels are directly over the metal "T"s.  Now you can either wire tie or zip tie the Lite-Form ties directly to the metal "T"s to hold the stem wall forms in place.

After the pour is complete and concrete sufficiently cured, take your angle grinder with cut-off wheel and cut the metal "T"s flush with the outside edge of the footing.

Another alternative would be to make a 1-1/2" deep saw cut in the top of your footing forms where a metal "T" needs to be placed so that the leg of the "T" can drop in this slot.  Then, no cutting of the "T" is needed until you get ready to remove the forms.


rgbUser is Offline
New Member
New Member
Send Private Message
Posts:21

--
15 Nov 2008 04:58 PM

Arkie,

I just poured a footing/frost wall monopour using a slightly simpler mehod than that.

I followed the instructions on the Fabform FastFoot web site for a method developed by a brilliant ICF builder in Idaho. The cross ties on the footing form are drywall hat channel. I cut it in bulk and screwed it on with a single drywall screw in each end. I then added steel stud track to align and support the ICF form (not Lite Form -  never Lite form) The track is fastened to the hat channel, the ICF is fastened to the track.

I poured the first load of concrete quite dry and vibrated it into place to fill the footing form and maybe halfway up the first ICF form. The rest of the concrete is poured as normal.

I braced everything from the outside using vertical 1 x 3 fastened to the forms with a diagonal 1 x 3 to a driven stake.

Easy.

The totally enclosed footing form shown above would not be permitted in my part of Canada as the municipal inspector must be able to see the depth of the concrete in the footing and the quality of the pour. Also, if the whole top isn't open the weight of the concrete falling on it will blow it apart.

rgb




BEN694User is Offline
New Member
New Member
Send Private Message
Posts:1

--
15 Nov 2008 11:00 PM
this is my technic for frost wall and footing + drain in same pooring with form-a-drain system.


tlynchUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:105

--
18 Nov 2008 12:42 AM
I think the last post is spam.

RGB - I like the solution that you just explained. Quick question - is there an open gap between the ICF and the top edge of the footing form on each side of the ICF blocksl? Is that why you pour the first pour dry? Do you have a link to where the system is described on the FastFoot website? I think that I am going to ask my foundation guy to consider this method when I finally get around to building.

It would be great if FastFoot designed a system that basically is what you just described, but also allows the FastFoot form to continue over the top of the footing and lock into the channels.


tlynchUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:105

--
18 Nov 2008 12:50 AM
Ignore me. Found the page:

http://www.fab-form.com/projects/Fastfoot/Residential/triple_a.html

This system is great. Thanks.


You are not authorized to post a reply.

Active Forums 4.1
Membership Membership: Latest New User Latest: vtsailor New Today New Today: 0 New Yesterday New Yesterday: 7 User Count Overall: 28619
People Online People Online: Visitors Visitors: 94 Members Members: 10 Total Total: 104

GreenBuildingTalk

Welcome to GreenBuildingTalk, the largest, most active forum on green building. While you can browse the site as a guest, you need to register in order to post.

Register Member Login Forum Home

Search Directory

Professionals Products

Get Free Quotes

Tell us about your building project and get free quotes from green building professionals. It's fast & easy! Click here to get your free quote.

Site Sponsors

For Advertising Info:
Call 866-316-5300 or 312-223-1600

Professionals Serving Your Area:

Newsletter

Read the latest GBT Newsletter!

Copyright 2011 by BuildCentral, Inc.   Terms Of Use  Privacy Statement  Free Quotes  Professional Directory  Advertising Programs