I am having garage/studio constructed using ICF for the lower level, with roughly 3, 16′ walls below grade into a hill side.
I noticed that when they installed the peel and stick water proofing membrane they started right at the footing and ICF joint and went up. They then added drainage rock, permiable cloth and drain tile and then backfilled.
I am not a construction person but, I did ask them if it would make more sense to have run the membrane lower so it would cover the ICF/footing joint and run over the footing edge before adding rest of the stuff. They said it was no big deal.
The footing uses vertical rebar, no key way to secure the walls. Does the concrete between the ICF and the footing creat enough of a seal?
Thoughts?
I live in the NW Montana, a fair bit of rain, snow and frozen ground in the winter.
Thanks.
Replies
zella.
That was done correctly. the purpose of water proofing is to prevent water pressure from forcing it's way thru the seems in the ICF's. Cover the seams and it's not possible for water to seep thru.
Frenchy is wrong. It is *possible* for water to penetrate that joint. And it has nothing to do with the seams in the foam. You are asking about the joint between footing concrete and wall concrete
But for practical purposes, it is highly unlikely.
They have provided a drainage path for water to move thru the drainage system far easier than it could move through that joint.
If the day ever comes when that drainage system fails, then there could be some hyraulic pressure forcing water into that joint, but if that does come, it will come to the interior of the structure under the slab, and those few drops would then find a way to percolate into the soil there.
I work in a lot of clay soils and places where ledge and springs flowing make redundancy wise, so I do lap my water shielding membrane out over the footer, but I am known for overkill. In most soils, given the description you make, you should not need to worry about this.
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Piffin is correct.
It's possible but not likely I stand corrected..
While it isn't a huge issue and the benefits might be minor, many engineered waterproofing membrane systems have the membrane running over the edge of the footer a bit.
While water entering at this level is typically under the slab and moisture barier, with some of our practices it isn't. Water migrating through this cold joint comes in on top of our moisture barrier and would pool in the sand under the slab. Typically not a lot of water at most and evaporation through the slab would take care of it with nobody being the wiser.
Having said that, there are engineered solutions that are comonly used in comercial construction and engineers and architects used to commercial jobs will sometimes include the details in a residential project.
Vinyl water stop is made just to span such cold joints and it reminds me of lawn edging, being about 4-6" tall and 1/4" thick with a barbell cross section. It's first cast into the footer with half the barbell sticking out, then the wall pour seals around the upper portion. To work it has to be detailed carefully at corners and at seams. View Image
Then there are rubber water stops made with bentonite, which swells when wet, sealing the cold joint. These are nailed or glued to the center of the footer and the walls are poured on top of it. As long as the material remains in contact with the cold joint it expands and seals. This stuff has been our choice when engineers have speced it.
Good building!
Beer was created so carpenters wouldn't rule the world.
Thanks for the explanations.
I had exactly the same question when they did mine a few weeks ago. It seemed like a strange practice, but I gather it is fine as is.
I would never do that , particularly with ICFs.
The reason is that with the ICFs you cannot see if there is a void at the bottom of the pour. One has to assume that there is solid and continuous contact between wall and footing
All it would take is one cell that for whatever reason failed to be completely filled right at the footing interface and you now have a hole through the concrete wall adjacent to the drain line.
Water will find the path of least resisitance.
In theory the drain line provides that path, but sometimes reality overcomes theory.
Something to worry about? Probably not.
Just my .02
Water will find the path of least resisitance.
One new ICF basement I was asked to look at had liquid water running through the ICF wall with enough volume to create what appeared to be a small stream. No kidding, water coming out of the middle, top and bottom of the wall.
The contractor poured a stiff mix and didn't vibrate at all. Honeycombed in many places, but hidden from prying eyes by the foam.
It was easy enough to suggest resloping the yard, digging out the exterior and water proofing the foundation, but the kicker is there's no way to know if anything is worth saving without tearing into the foam. The suggestion that there's a remote chance the entire foundation needed to be scrapped didn't go over well.
Cheers
Beer was created so carpenters wouldn't rule the world.
That is a concern I have had about ICF's. I have never built with them but it is not hard to imagine a pretty poor job of consolidation being done when using them. A lack of attention and you end up with just what you described.
They can't get your Goat if you don't tell them where it is hidden.
build yurself a test wall short of pour....
good way to get a feel for them...
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WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
I don't think I would have any problem with them myself, just haven't had a call for them on any job I have been on. I started pouring high wall back about 1974 or so . It is those without the experience to know what to look for that I worry about.
It wouldn't be impossible to have complete voids in more then one cell if things don't go right. Makes me wonder about the structural integrity of some pours, there is just no way to see what problems may be there.
They can't get your Goat if you don't tell them where it is hidden.
Makes me wonder about the structural integrity of some pours, there is just no way to see what problems may be there.
I've seen daylight coming through ICFs, many places. The architect owner/builder thought it was funny until I suggested that they could only see a tiny part of the problem. They continued building the house. 30' tall walls, honeycombed.
One of many reasons I prefer what I traditional casting.PAHS Designer/Builder- Bury it!
I have done ICF's for many years now and have yet to have any problems with waterproofing including one instance where we had an underground spring that flowed to a basement wall. I have used several different methods and finally settled on the following. In areas of extreme moisture (i.e., a spring) we use a product from Certainteed called "form-a-drain" which is nothing more than 2x8 vinyl footing forms that double as permanent drainage. You end up with continuous drainage on the interior and exterior of your footings and even more importantly it's placed to the side of the footing. This first step is optional. More often than not we place perforated PVC (NOT the corrugated black stuff) on top of the footing. This actually comes after we place one row of peel and stick EPDM lengthwise along the footing. We try to get at least six inches of EPDM on the footing with the other 30 inches placed up the wall. The rest of the wall is coverd with what I call a "drain curtain". There are several on the market, all of which we have found to work quite nicely. However, we always use Armtec system platon ( http://www.systemplaton.com ) because that's what our local retailer sells...at least after I got them to. A couple of key points. I only use PVC drainage with holes on one side only and that side goes DOWN per manufacturers specs. Water always follows the path of least resistance and what is created is a fancier version of a French drain. If you place the holes up then water has to build up to that point before it will get into the pipe and by then it might be in your basement. You can make the case for pipe that's perforated all over...I can't give you a good reason for not using it. We then backfill the first buried third of the way up the wall with washed gravel for two reasons. 1) Excellent drainage. 2) It exerts the least amount of pressure against a wall than other types of backfill. We always put at least one "cleanout" on our drainage system to make it easy to clean should a clog be suspected. I never use filter fabric and probably never will. Let's see, I don't want this pipe to clog so I'll put something over top of it which will clog with fine particulate? I cannot stress this point enough...EXCELLENT DRAINAGE HAS WAY MORE TO DO WITH DRY BASEMENTS THAN ANY WATERPROOFING GOO YOU CAN PUT ON YOUR WALLS. The reality is this, although we put the membrane on the footing there is simply no way with our method that we are getting a perfectly watertight seal against the footing. It's just not that sticky. Our success is due to the air gap membrane which allows moisture to condense on the outside of the ICF wall and run down to the drainage...EPDM all the way up the wall doesn't do this. It actually seals moisture in as well as out. And most importantly, excellent drainage that's easy to maintain over a long period of time.
I'd love to read that.
Is the enter key broken on your keyboard?[email protected]
I took the challenge of deciphering it to something readable, 'cause he seems to have something worth reading...."I have done ICF's for many years now and have yet to have any problems with waterproofing including one instance where we had an underground spring that flowed to a basement wall. I have used several different methods and finally settled on the following. In areas of extreme moisture (i.e., a spring) we use a product from Certainteed called "form-a-drain" which is nothing more than 2x8 vinyl footing forms that double as permanent drainage. You end up with continuous drainage on the interior and exterior of your footings and even more importantly it's placed to the side of the footing.
This first step is optional. More often than not we place perforated PVC (NOT the corrugated black stuff) on top of the footing. This actually comes after we place one row of peel and stick EPDM lengthwise along the footing. We try to get at least six inches of EPDM on the footing with the other 30 inches placed up the wall. The rest of the wall is coverd with what I call a "drain curtain". There are several on the market, all of which we have found to work quite nicely. However, we always use Armtec system platon ( http://www.systemplaton.com ) because that's what our local retailer sells...at least after I got them to. A couple of key points. I only use PVC drainage with holes on one side only and that side goes DOWN per manufacturers specs. Water always follows the path of least resistance and what is created is a fancier version of a French drain. If you place the holes up then water has to build up to that point before it will get into the pipe and by then it might be in your basement. You can make the case for pipe that's perforated all over...I can't give you a good reason for not using it. We then backfill the first buried third of the way up the wall with washed gravel for two reasons. 1) Excellent drainage. 2) It exerts the least amount of pressure against a wall than other types of backfill. We always put at least one "cleanout" on our drainage system to make it easy to clean should a clog be suspected. I never use filter fabric and probably never will. Let's see, I don't want this pipe to clog so I'll put something over top of it which will clog with fine particulate? I cannot stress this point enough...EXCELLENT DRAINAGE HAS WAY MORE TO DO WITH DRY BASEMENTS THAN ANY WATERPROOFING GOO YOU CAN PUT ON YOUR WALLS. The reality is this, although we put the membrane on the footing there is simply no way with our method that we are getting a perfectly watertight seal against the footing. It's just not that sticky. Our success is due to the air gap membrane which allows moisture to condense on the outside of the ICF wall and run down to the drainage...EPDM all the way up the wall doesn't do this. It actually seals moisture in as well as out. And most importantly, excellent drainage that's easy to maintain over a long period of time.
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Thanks Paul,
Yes there was interesting information in there!
I sometimes can't help but be a bit of a wise azz. I can't for the life of me figure out how anyone can expect something in that structure to be readable. I got a headache just looking at it.
Judging by further posts by him, he didn't take my wisecrack to heart a bit. I type like #### and slow, but I understand the value of white space.
Have a very nice Christmas!
Eric[email protected]
No problems with inspections as blended steel fiber is code approved. We use a product provided through our concrete supplier call Novomesh made by SI Concrete Systems. (see http://www.fibermesh.com/application.aspx?ID=2177 for more details) I've even used them on below grade walls but that's a lot trickier...definately would consider an engineer although at one time, SI would do that for you as part of your purchase price. The stuff isn't cheap but since we add our verticle rebar at the end, the elimination of horizontal rebar allows you to FLY! We end up stacking forms 3-4 rows at at time in staggered fashion somewhat like a roofer lays shingles.
I was once told that I talk a lot...but not too much. There's a big difference.
Not sure what you are getting at, but there was no offense intended in my post to you. I'm a wise azz with old eyes. Looking at 10-15 paragraghs of writing all bought together with no breaks is REALLY hard on my eyes and eyes in general.
You brought lots of good info to the thread, thanks.
Eric[email protected]
I absolutely was NOT offended. My Dad even gives me a hard time saying, "For someone who talks so much you sure don't say anything."
You can't be in construction and have thin skin.
Steven, by using no filter fabric, you gaurantee that your perimeter drains will be silted up and non performing sometime in the next 30-50 years
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If they do get clogged that's what the cleanouts are for.
good luck with that
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dovetail,
Please read my response to Don.. . I've done ICF's and watched dozens since I did my first one in 2000. The situation described by Don would require a extremely rare combination of foul ups. Situations which are simply unlikely to happen if you read why.
I'm proud of the fact that my last ICF wall was a radius wall built on top of footing forms and I poured the whole thing,, footings, wall and floor in one 4 hour pour (and even had enough time to pour footings for a retaining wall down my driveway)
To avoid honeycombing you simply look down at the concrete as it's pumped out, if it's coming up from the bottom as it should you have a solid pour if it's hanging on the rebars which will give you the potential for honeycombing there are additives which can be added and will eliminate that risk without losing strength.. Vibrators are of course called for and should be used.. that's sort of like building without nails..
as for too stiff a mix.. most pumpers are owned by the redi mix plant and they know how stiff they can pump.. , if you get over the stiffness called for in forms you can't pump it!. They know that and know what sort of mess too stiff a mix will cause..
If you buy your forms from the same company that will pump you and sell you the concrete they should pretty much hold your hand thru the process.
I Can't tell you how easy it is, except to say that when I couldn't finish my first foundation, my sister -in-law with no prior experiance and only my drug slurred instructions as her only guide finished my whole foundation. (I 'd started the first two courses) on a Saturday by herself..
All I did was put the bracing/scaffold in place (rental was included in the price of forms) took a couple of hours and then they came out and checked that everything was ready..
We've had great luck eliminating horizontal rebar almost entirely and replacing it with steel fibers in the concrete mix. With only verticle rebar (except for over headers of course) even suspect mixes pour well. I've only ever refused one load of concrete...it was really bad. There were a couple of others I probably shouldn't have poured but they were above grade walls where honeycombing was a more cosmetic/thermal issue rather than a structural one.
stevenplane,
I've heard of doing that but I thought the rebar added a lot of rigidity to the forms during the pour. Do you use added bracing to make up for the lack of rebar?
I had no concrete pouring experience before my first ICF pour so I've never had anything to compare the bracing to. I've heard this a lot...that is to say trouble bracing ICF's "solid". I brace my corners rock solid with wood, not my specialty scaffolding. This allows me to pour my corners much more aggressively with no fear of blowouts. It also gives me precise points to pull stringlines from for wall alignment. We also "brace" the bottoms of my walls using 2 1/2" metal channel that is designed for steel framing. We use the thinner guage and anchor it to the footing with ramset nails. We only do one side of the form...the side that has our scaffold. We use the same kind of channel, only the thicker guage, for the top of our wall. This makes it easier to get "perfectly straight" wall alignment. Thicker guage is more durable and as a result, reusable. It also is a good way to protect the teeth on the forms if you plan to do another level. The scoffolding units are anything but "solid". They wobble all over until you get concrete in the forms. I always lean my walls in just a bit until I get my first "lift" poured then gradually bring them out to my stringline at that point. I prefer to not let the walls ever get "outside" of my stringline because you run the risk of making it a real pain in the a** to get them pulled back in. In my experience flexibility rather than rigidity is more important to a successful pour.
stevenplane,
I'll have to acknowledge your experiance and accept your opinion..
I know that I wouldn't have poured my 9 1/2 foot radius wall without rebar in place (I use reward forms and the rebar just snaps in place no tiewraps needed) I cut the basic form into three pieces and foamed the joint. I then cut some oak I had at a 7 1/2 degree bevel and joined them together using screws. put them at the splice..
I set this whole thing on top of forms to hold the footing and made the pour , footings walls and floor all at once. I'd already back filled the outside and since the top was tied in place with the joists I used I didn't feel the need for any bracing.. it was that rigid!
The pump guy wouldn't pour with out bracing so I quickly scabbed some in place but left it slightly loose (Just to prove to myself) the pour went flawless .. and no the bracing wasn't required.
A radius is a different story altogether. Horizontal rebar would be a very efficient method of giving the wall some rigidity. In fact, I'd have to really put some thought into it to come up with any other way of doing it, let alone a better way.
I'm a fan of Reward myself...6" oc ties are nice for fast agressive pouring.
stevenplane,
so where do you work? and are you feeling any of the effects of the slow down?
Have you compared the price of your work to say SIP's or other energy efficent ways of building? In general here in Minnesota I was seeong about a 5 to 8% premium untill about 2005 when I started to see as little as a 2% premium as more guys got used to working with it and developed the efficent methods of building..
Then last spring the damn burst and people were doing anything to stay busy including selling ICF houses for the same price as Stick built.. It didn't seem to work as the last few ICF houses were in the trim stage by last fall and since then I haven't seen any new ones going up..
The pump guy wouldn't pour with out bracingthat not his job or concern, he would of been fired in a heartbeat
When you guys pour a foundation do you ever have a testing company on site to test the concrete. I know there are some concrete dispatchers out there who will, and have dumped off a bad batch of concrete on someone is is unsuspecting. For instance, a truck gets turned away from a highway job because of to much air, instead of dumping it they send it your way and half way thru the pour it is setting up. Now you have a lot of honeycombing in your wall. Do these results sound familiar? Just a thought!
happens all the time
Edited 12/24/2007 10:36 am by brownbagg
when we pour ICF with pump truck. we have an understanding with the operator. I keep it wet enough so he donesnt get clog, and protect the pump at all time. he doesnt interfer with the trucks or the pour.I add the water, I sign the tickets, I turn down the trucks. i back the trucks up. He just pumps.we usually pump a three inch slump pea gravel, then add super, that gives him about a six in the hopper. we use alot of 36-42 meter trucks so he lose about a inch in the lines. we add a tremby to the hose so it controls free fall.opereator know at anytime he can blow/dump his system if he start getting clog. 5000 psi you got to keep an eye on it..
Edited 12/24/2007 10:44 am by brownbagg
I agree that a conscientious contractor will find it hard to create voids in an ICF. Somebody has to almost TRY to screw up the job to create so many voids that water will run through like that. Souinds like a bunch of druggies were placing that stuff.But
"as for too stiff a mix.. most pumpers are owned by the redi mix plant "that must be a regional thing for you. More of a rarity here. The only pumper I know of that was owned by the batch plant got spun off to be a separate entity like the rest of them around here.
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Do you have any problem getting inspected with no rebar?
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IdahoDon,
there isn't anything made by man that can't be screwed up with enough effort.. But to have a problem with honey comb really calls for major effort..
Too stiff a mix? sounds like a problem for the concrete company.. pretty hard to pump when it's stiffer than what ICF's call for.. Most concrete companies own their own pumpers so you'd think they would know. On top of that you are standing right over the forms watching it pour in. If it's not coming up from the bottom but hanging up on the rebar or whatever that is clearly obvious.. plenty of additives companies can use to achieve a proper pour even with too stiff a mixture.. additives most concrete trucks carry with them as a matter of course..
Piffin and Idaho Don have given you good advice, which I want to expand upon.
Paying careful attention to site conditions and positive drainage is the cheapest and most effective part of the strategy. A footing drain is always good, too.
As for the joint between the wall and the footing, when building on sites where I know there is a water problem, I will install a cant strip at the base of the wall where it meets the footing and run the membrane down the wall, across the cant strip, and out over the edge of the footing, where the water can find the drain. Any of the plastic dimpled drainage planes are also good.
As for the cold joint, it is a legitimate concern. Don is right on eery count in his comments. Keyways are good, and don't cost anything to install, just tool a keyway with a 2x4 on edge along the verticals while the footer is still plastic. Another less expensive and easier way to go than cast-in waterstop is a dash coat of Portland cement in a mixture of half water and half Anti-Hydro and apply it right before you place the concrete for the walls. Of course your footers are clean, no dirt spilled down inside the forms.
Most critical, as noted, is to avoid rock pockets, voids, and honeycombs. Your concrete should be a 3/8-minus pump mix batched at a slump 4 and brought up to about a 7 or 8 with super-plasticizer. The concrete should be placed continuously, start in one corner and work in fairly shallow (about 2') lifts, placing the concrete against the leading edge, using the pressure of the pump for consolidation. Work against that leading edge of the slump, drawing it with you as you go, just like you paint to a wet edge.
Have a helper rod the concrete down as you go. If you want to vibrate it, take the blade out of a recip saw and run the shoe on the outside of the forms. Forget about using a concrete vibrator unless you actually know what you are doing with it. You can do far more harm than good.
Work your way around the forms in this manner until you get back to the starting point, and then repeat the process.
If you have a good mix and it is placed properly there is no reason whatsoever for voids or pockets.
You may also find it helpful to leave the top horizontal out until the concrete is placed up to that level, it cuts down on the spatter, splash, and aggregate segregation.