Concrete/wall question.

[bluesman2a]

OK, so in my seemingly never-ending dealings with my contractor on my retaining wall. I've hit a new snag: the engineering drawings on the wall call for a 2" X 4" keyway on the foundation and there is NO keyway on the foundation, it's flat.

So my questions:
1) Is the keyway necessary? I have a call into the engineer to see if leaving it out is a problem and what the remediation would be if it isn't there. I just haben't heard back from the engineer.

2) How difficult would it be to put a 2 X 4 keyway into 139 linear feet of foundation? How would it be DONE? I can't see any way to do it that's not a complete PITA.

 

[PAToyota]

A retaining wall can be designed either way, but if it was designed with one it is necessary - it helps to keep the wall tied to the foundation and not push out. The engineer can probably come up with rebar to dowel into the foundation to take the place of the keyway, but it is sounding like your contractor really doesn't know what he is doing if he omitted a detail that was on the drawings....

 

[kbs2244]

I am with PT on both points.
In my part of the world they are so common, I would expect a cement contractor to put one in, even if it wasn't on the drawing.
Any poured wall sitting on a footing needs to be keyed to the footing so it dosn't slide off the footing when under side pressure.
Unless it is a pretty low wall that won't see a lot of pressure, the only thing I would accept would be cutting the slot out with a concrete saw. The cement is fresh enough, so it shouldn't be too hard to do.
I just don't think rebar pins are going to have the strengh all along the joint to hold back any kind of real pressure.

 

[MXtras]

Both posts above ring 100% true - it should not be ommitted if it's in the design.

Scott

 

[bluesman2a]

So the contractor for the foundation is offering to come in and either cut the keyway or credit me for $3 per foot to have somebody else cut it (139 feet). Anybody have a clue which is a better deal or if that's adequate? The current contractor will NOT be coming back to finish the wall, so I don't trust them to get the keyway correct, but I don't want to take a bath at the $3/foot price either...

<argh> this is SUCH a mess.

On the plus side, I just finished with the concrete company and got their price (for what was already poured) down from $122 per yard to $112 for 2.5" line pump mix. Not a great price, but not like I'm bending over the barrel at this point.

 

[MXtras]

If the original prints called out a key and he did not put it in, tell him it's his baby to fix and stand your ground. He has to fix it if he wants to remain in business.

This is why they make lawers and this is a legit reason to sue, unlike 90% of the **** you read about these days....

Scott

 

[PAToyota]

Who did the engineering drawings? I'd have them look at the situation and advise. As for KBS's comment that rebar won't take the place of a keyway, it may end up being #12 bar to do the trick... (1 1/2" dia...)

 

[boiler7904]

To answer you're questions:

1. Yes it is necessary unless you have an engineer that will accept steel rebar drilled and epoxied into the footing.
2. Yes, It will be a PITA. Cutting concrete is always a less than fun experince.

I'd have the original contractor cut the keyway and make his payment for the footing work contingent on three things (assuming you haven't paid him already):

1. It meets the approval of the engineer who designed the wall.
2. It passes all building inspections.
3. It is an acceptable substrate for the wall according to the contractor whose work follows. It's great if he makes a cut - not so great if no one will form and pour the wall because of something in the footing.

$3 a foot for 139 feet is just over $400. Cutting all of that is more than a day's work for one guy - probably enough to keep two guys busy for at least a day. Unless you've got a contractor who's paying his guys minimum wage, the new contractor isn't likely to want to do it since there isn't really any money to be made (and he has to fix someone else's mistakes on top of it). I'd consider calling a specialty concrete cutting or demolition company and have them give you a ballpark price over the phone. Should make it real easy to see if this guy is trying to hose you (again) or not.

 

[bluesman2a]

Boiler... that sounds emminently reasonable... Thanks for the feedback.

 

[Bigger Hammer]

If they cut it out, how are they going to remove the concrete for the keyway? remember that if they cut it, it will have to be cut on two sides, thus doubling the linear footage. Maybe that is what the $3.00 a foot includes but considering what needs to be done I think that sounds a little on the low side to me. In addition to that, the last thing I would want to have done to my new footing is a portion of it cut away and then jackhammered out. The hammering will most definitely cause stress fractures throughout the entire footing and weaken it below design strength. I am assuming that there are already rebar dowels sticking up out of the slab to prevent uplift and some shear. I know that an engineer could approve a method for drilling dowels and epoxying them into the footing to equal or exceed the shear strength of a 2"x4" key way.

Honestly I really wouldn't get too worked up over it if it was mine. At least in my head I wouldn't, I'd still beat the concrete sub up over it and get some money back out of him.

fwiw, I'm a Gen. Contractor superintendant and have poured 1000's of feet of concrete walls so it isn't as if I'm some jagoff that doesn't have a clue what I'm talking about.

 

[SCOOTER]

If they cut it out, how are they going to remove the concrete for the keyway? remember that if they cut it, it will have to be cut on two sides, thus doubling the linear footage. Maybe that is what the $3.00 a foot includes but considering what needs to be done I think that sounds a little on the low side to me. In addition to that, the last thing I would want to have done to my new footing is a portion of it cut away and then jackhammered out. The hammering will most definitely cause stress fractures throughout the entire footing and weaken it below design strength. I am assuming that there are already rebar dowels sticking up out of the slab to prevent uplift and some shear. I know that an engineer could approve a method for drilling dowels and epoxying them into the footing to equal or exceed the shear strength of a 2"x4" key way.

Honestly I really wouldn't get too worked up over it if it was mine. At least in my head I wouldn't, I'd still beat the concrete sub up over it and get some money back out of him.

fwiw, I'm a Gen. Contractor superintendant and have poured 1000's of feet of concrete walls so it isn't as if I'm some jagoff that doesn't have a clue what I'm talking about.

You took the words right outta my mouth.........

 

[Bigger Hammer]

You took the words right outta my mouth.........

Thanks, I was afraid I may have opened up a can of worms with that one. It's just that I've seen soooo many different designs and one engineers "just enough" is another's "complete overkill".


Besides, half of us contractor types can't read plans anyway

 

[mandersen]

Hi,

When pouring una-slabs for additions, footings and slab as one pour, we always poured stub or short walls directly on the slab for walls later......How do you anchor them? 3/4 inch rebar six inches into the slab while wet. Since yours is dry/set, you can do the same by drilling 7/8 inch holes 24 inches o.c. If your wall is 48 inches high, then your vertical rebar should be 54 minimum. Bond this to slab in the holes with construction masonry epoxy. This is the same stuff contractors use to bond cracked poured foundations together with when mother nature rears her ugly side...... But contacting a structural engineer or the inspector might help too......

Mark A.

 

[bluesman2a]

OK so a quick update here:

I fired everybody. I'm now 95% clear on all my previous contractors (thank gawd). Got a refund from my general (which immediately bounced at HIS bank, but he's made good).

Then I found that every purchase the GC's company made at the masonry supply where I got the rebar has been going on MY credit card since my name mysteriously got associated with his account. THAT's now cleared up.

Called the concrete company, and beat them down on pricing and have THEM paid off (GC dodged that too).

The engineer has given us a letter saying that #6 rebar 24" long and 24" apart sunk 6" and epoxied into the footers will remediate the keyway issue. The original contractor on the wall will have to come back in and do that before I pay them, but that should happen early next week.

Best of all, I've found a wall company I think I can work with, reputable, responsive, and reasonably priced. They'll be coming in once I get the foundation remediated.

 

[Beegs]

OK so a quick update here:

I fired everybody. I'm now 95% clear on all my previous contractors (thank gawd). Got a refund from my general (which immediately bounced at HIS bank, but he's made good).

Then I found that every purchase the GC's company made at the masonry supply where I got the rebar has been going on MY credit card since my name mysteriously got associated with his account. THAT's now cleared up.

Called the concrete company, and beat them down on pricing and have THEM paid off (GC dodged that too).

The engineer has given us a letter saying that #6 rebar 24" long and 24" apart sunk 6" and epoxied into the footers will remediate the keyway issue. The original contractor on the wall will have to come back in and do that before I pay them, but that should happen early next week.

Best of all, I've found a wall company I think I can work with, reputable, responsive, and reasonably priced. They'll be coming in once I get the foundation remediated.

Good news on finding another contractor! Around here it is nearly impossible to get someone to pour on somebody elses footings.

I prefer the vertical dowel design over the keyway. Not only will it help keep the bottom of the wall in place, it will now make the wall act as a beam, helping it to span soil that may have been disturbed more than it should have as an example.

 

[Bigger Hammer]

What an absolute nightmare!! Stories like this make it seem so easy for me to break out on my own and run a reputable company. lol

Very glad to hear that things are at the very least back on the right track and you have your money woes figured out. Hope that credit card mix up doesn't come back to haunt you some time down the road.

 

[bluesman2a]

What an absolute nightmare!! Stories like this make it seem so easy for me to break out on my own and run a reputable company. lol

Very glad to hear that things are at the very least back on the right track and you have your money woes figured out. Hope that credit card mix up doesn't come back to haunt you some time down the road.

Thanks all, I appreciate the commiseration. I have no doubt that an honest man who has two goals could make a mint in this industry. If you just a) call people back and b) do what you say you will do I know you would have more work than you can handle!!!

It would be one thing if I were a "difficult" or uninformed customer, but I'm really NOT (Lord knows I deal with enough of them in my own line of business). In fact I would go so far as to say I WANT to be any contractor's BEST customer, clear scope of project, no changes that aren't in writing and pre-costed, and payment ON TIME when work is completed to satisfaction of the agreement. Is that too much to ask?

As for the credit card, I'm good on that one too, the bank has them all in dispute, and I have the refund reciepts from the vendor. Also cancelled the card, so now it's just a case of waiting for the refunds to post...

 

[bluesman2a]

OK, I would like to thank everybody for their assistance and advice so far, you guys have been a HUGE help.

As of today, we have the foundation completely remediated!!! The old contractor came back in, put in the #6 rebar and epoxied it at no cost to me. So I did let them do it, but I watched them like a hawk.

So my next question (sorry for all the questions): I'm talking to people on the drain-tile for the wall... Some are saying to waterproof the backside of the wall, some are not. The idea is that the waterproofing will keep the calcium from going through the concrete.

I don't plan on doing anything with the wall in the way of a covering (no brick, etc.) in the near future, so I don't know if it makes a difference. I mean this IS a retaining wall, but I would like to maintain the aesthetics over time (or at least as much "aesthetic" as a poured wall CAN have).
any thoughts here?