Not to disagree with you KCMOK, but a capillary water break is not what we have here. A water break must be continuous, this is not, and in order to maintain structural integrity a minimum 2 inch deep 4 inch wide trough has to be driven into the foundation that is in filled by the concrete wall.

Structural integrity between the wall and its foundation are of paramount concern, water penetration is of secondary concern and any 'solutions' to prevent water penetration should not be allowed to compromise structural integrity.

Now, do any of you have a solution to the problem?

Since its too late for a key way with water barrier. I would consider laying two beads of self adhesive butyl water stop 2.5" & 4", respectively on the exterior side of the vertical rebar. They will embed in the fresh concrete and create an effective barrier to water migration.

I believe the plastic sheets will actually promote water migration.

Are keyways always necessary in the footer? I thought that vertical rebar that ties in to the verticals of the form (40d rule) should be enough. Certainly a keyed footer will strongly interface with the wall but is it truly necessary?

Also,

 

This is a nice link to Mr UFER in case anybody is interested.

 

LINK


Leonard

The house designer & TurboCAD guru who reviewed my plans in the early stages of drafting suggested this same thing. On the other hand, the
PRESCRIPTIVE METHOD FOR INSULATING CONCRETE FORMS IN RESIDENTIAL CONSTRUCTION,Second Edition, published by U.S. Department of Housing and Urban Development as part of the PATH project doesn't say anything about keyways, but instead calls for dowels, and even then only for serious side loading conditions. I can't find in the 2006 IRC what is required for the footing to ICF wall connection. Here's the requirement from the Prescriptive Method:

6.1 ICF Foundation Wall-to-Footing Connection
No vertical reinforcement (i.e., dowels) across the joint between the foundation wall and the
footing is required when one of the following exists:
• The unbalanced backfill height does not exceed 4 feet (1.2 m).
• The interior floor slab is installed in accordance with Figure 3.3 before backfilling.
• Temporary bracing at the bottom of the foundation wall is erected before backfilling and
remains in place during construction until an interior floor slab is installed in accordance
with Figure 3.3 or the wall is backfilled on both sides (i.e., stem wall).
For foundation walls that do not meet one of the above requirements, vertical reinforcement (i.e.,
dowel) shall be installed across the joint between the foundation wall and the footing at 48 inches
(1.2 m) on center in accordance with Figure 6.1. Vertical reinforcement (i.e., dowels) shall be
provided for all foundation walls for buildings located in regions with 3-second gust design wind
speeds greater than 130 mph (209 km/hr) or located in Seismic Design Categories D1 and D2 at
18 inches (457 mm) on center.
Exception: The foundation wall’s vertical wall reinforcement, at intervals of 4
feet (1.2 m) on center, shall extend 8 inches (203 mm) into the footing in lieu of using
a dowel as shown in Figure 6.1.

I take it you're referring to my quote of the NEC. Actually, I did Google UFER to make sure what it was, but I already knew about tying to the rebar from discussion with the electrical inspector and reading the IRC. I copied the quote from my own personal copy of the IRC, not from any web site! It's a great resource to have and well worth the $60 it cost. :-)

Thank you for the kind words!

OK, nice to see someone has a suggestion, although it wouldn't be my approach, there's a product by the name of Densicrete that will eat into the plastic barrier, sink into the concrete, travel down the new dowels and crystallize the surface of the steel and the whole of the cement in the concrete to a dept of 4 inches or so.

After crystallization the itself cement will be water proof, and the dowel protected against oxidization by the very first level of rust already promoted by the cement.

There are many tricks to solve 'poor workmanship' available to people who fix things, including exotic remedies such as the use of carbon fiber, aramid fibers and a myriad of complex epoxies.

As to a key-way, it is a required element of a 'damp proof course' as the method of build here would best be described, but since it's not possible to introduce one at this stage then the remedial solution would be to destroy the integrity of the plastic barrier as outlined above.

If you can't get hold of Densicrete a simple acetate based concrete bonding agent used in conjunction with a styrene free concrete plastisiser added to the concrete mix for the first 18 inches of the pour would be adequate.

OH, PS. Hope my spelling comes up to speck for an 'expert' LOL.

The plastic will come out tomorrow before I pour, it shouldn't be too hard since I can lift the interior panels and reach inside the wall. (for a video of this feature check out link)  I don't know if this is good advertising for TF system or not, but it is helpful where one makes an error like I did.

I could also drill holes in to the footing and epoxy in stainless rods to take the place of those rusting rebar "dowels".   I don't live in an earthquake zone,  but this is the house I intend to pass on to my kids and I certainly don't want them to have to deal with a failing foundation as my legacy. 

Thanks for all the discussion on this, funny how I thought I was doing the right thing, though now I see  AND comprehend  the keyway in that cross section on buildingscienceconsulting.com. 

I'll let y'all know how it goes tomorrow.

Ben

That would be the hard way Ben, droping the solution in would take 20 mins max and cost about 70 bucks.

Thanks for the encouragement, glad to see I didn't do everything wrong.

(I should be able to remove that plastic layer easy enough, just tear it to the inside, or lift the panels and cut it out if I have to. )

Ben

That'd be fine mate, use the densicrete to protect your re-bar, its well worth the wait to get it shiped. If I had some on hand I'd send it too you, but I just finished a big fix it job and ran out of everything other than zip ties and kevlar.

Here's their website

Looks like that website is dead, try this one

Ben
Leave the plastic. Not the easiest capillary break to install but it works fine and is far better than nothing. We've had great luck with concrete sealer specified for green concrete. This is to be sprayed on the area where the concrete cavity will sit on the footer.
Great pictures. Good choice on the wood, they are the best bang for your "buck."


We have performed commercial demolition projects in the past, and torn up concrete slabs. The visquine under the slab has become an integral part of the system. It would seem glued to the concrete above and formed to the subgrade below.
To think plastic on the footer would allow water intrusion is ludicrous, any more that the plastic webs are water intrusion points... No concrete to concrete connection such as wall to footer is waterproof anyways unless a keyway with a product like volclay rx101 is used, and to their exact manufacture specs using primer etc.
1/ slab elevation will be above the footing elevation.
2/ exterior waterproofing (preferably dimple membrane) should roll down the wall and over the footing anyways.

ACI 318 says dowels OR keyway, subject to specific engineering....

Kevin

What is ludicrous is to think that draping visquine over a footer and pouring a stemwall on top of that is an ok practice. Lets examine this for a second. By the looks of Ben's project hes looking at 5-6 feet + of backfill. When it rains its obvious that the ground water is going to eventually hit the wall and vertically travel down its path. Now lets just say that there is no water proofing membrane installed. The water will travel down the wall and hit the visquine on top of the footer.

Where is the water going to go? Some of it will flow off to the side of the footer into the ground. Thats fine. Some of the water will puddle agianst the wall and some of the water will make its way under the eps of the TF system. The water will then hit the concrete core and do as it pleases from there. Whether it intrudes or not is uncertain and that is what I don't like.

Now what about the water that makes its way underneath the visquine? Will this water will travel along the top of the footer and UNDERNEATH the concrete core of the wall? Well if you think about it chances are a definite yes because there is no way that the visquine could make a solid connection to the cured concrete in the footer.  Even with the weight of the freshly poured concrete on top of the visquine, the uneveness of the footer is going to cause small voids between the footer and the visquine thus creating a path for water to travel that really shouldn't even be there.

Structurally this addition to an icf system is a bad idea. It results in an unesscesary addition to a cold joint in your wall.

- Pete

Pete,

Plastic's out, here's how I did it.  Thanks for your help on this one.  Speak up when you see other things like this, maybe there's still time to remedy it.

Ben

Here's some more pics from the pour...

I ran a 1.5" vibrator in each space, dropping it till it tapped the footing.  We started under the windows and continued in a   3'-4' lift all the way around with me dropping the stinger about 6' behind the pump. 

Things went well until we reached the first corner with the second lift.  Note the picture with the long vertical black crack.  That's the ladder webbing, and there's not much more before we lose the corner.   Fortunately Dave saw what was going on and got some bracing in place very quickly.  I'd hate to  know just how close we came. 

 I NEED TO ADD HERE AFTER LOOKING AT THE ALMOST BLOWOUT WITH  THE TF SYSTEM NAME RIGHT BESIDE IT... THIS WAS AN INSTALLER ERROR DUE TO NOT FOLLOWING THE INSTRUCTION MANUAL.  THE MANUAL STATES ATTACH ANGLE BRACING TO THE C CHANNEL WITH 2 SCREWS.  I ATTACHED A BLOCK TO THE FOOTING USING TAPCONS,  RELYING ON THE BITE OF THE TAPCON THREADS AND NOT THE SHEAR OF 2 SCREWS THROUGH THE C CHANNEL.   I CAN JUST HEAR MY SALESMAN BEMOANING A PICTURE IS WORTH A THOUSAND WORDS, MAYBE I SHOULD TAKE IT OFF...

Now, I post these pictures because I want feedback.  Be honest, and don't worry about hurting my feelings.  Call me a flying monkey hack if it helps you say what you want to say.  I only do the best I know how, and I was admittedly in over my head today.

Thanks again for all the feedback on the plastic over the footing.  I always intended to cut it back flush with the forms and seal the joint with something.  Next time...

Ben

Capillary breaks are a great idea to avoid rising damp. Period. Chose your method, but chose a method.

Some will always build to code which are effectually, "minimum standards for legal construction practices" There are many of us who practice code plus construction for equivalent pricing.

Kevin

You did well holding the breach, that could have been messy.

What mix did you use Ben? I would have recommended a 6.5 slump, pea gravel, 4000PSI, and ensure they didn't throw any ash in there.

As to methods of pouring to stop corner break out I recommend starting at the corners with a fill of about 2ft and 'flowing' the concrete from the corner along the wall. In this way you can make sure that there is no separation of the cement and its aggregate, known here as 'graveling' but more properly termed as 'concrete shere'. If poured by this method the cement in the concrete doesn't get enough time to set up before the next flow of concrete gets placed, and the heat generated in the wall remains even throughout.  Little known in the field of ICF's heat in-balances in the pour are a significant cause of deflection and warping due to stresses created by differing parts of the wall curing faster than others. Significant factors that come into play is basements for instance are ground temperatures differing from one side of your foundation to the other normally related to ambient heat more readily retained on the south side of a footing.