Cold Joint Nervous

roadhouse

so i finally got our new house on the go. but, when my concrete guy was puoring the footer they were unable to finish the pour in one shot. it wasnt planned out like that, just some unforseen problems accured. but any way im very concerned about the "cold jiont" in the footer. it has rebar in it all the way around, so there will be bar where the joint is. the walls on top of it are going to be styrofoam and theres going to be rock laid under the slab. the footer is about 6 foot below grade (its a full basement) and laid on 'hardpan". should i have any concerns? any input will be greatly appreciated.

NJ Brickie

No reason for concern. Footings are poured in sections all the time. As long as the footings are doweled together and a keyway would have been a good idea.

roadhouse

would the rebar running through be considered "dowling". could you explain "keyed", ima plumber so not a familier word.

NJ Brickie

yes the rebar going from the old pour to the new pour would be doweling. A keyway would be a groove in the footing where the old pour and new pour meet. It is done by placing a V cut 2x4 into the form work at the pour stop (where the pour is going to stop) vertically. Then removing this and the pour stop after the concrete sets up.This leaves a groove in the old pour for the new pour to lock into the old footing.

roadhouse

thanks for the info, its to late to key it but atleast its dowled. hope i dont have any problems.

NJ Brickie

was a bulkhead placed where the old pour ended? What I mean is the footing stopped by a piece of formwork so that it is the full depth and does not just taper off? I would have some reservations if the footing just tapered off and you are going to have to pour over it in that section to level it off

Chris Johnson

Yes, if it is not squared off that can be an issue. It is fairly simple to clean it up if not, just use a Hilti and chip it as square (90 degrees) as possible.

Personally I am not sold on a keyway if you have rebar in a footing, shouldn't be required. It is considered old school, engineers still draw it as habit but no one can explain why it is still there or needed.

__________________
Chris

roadhouse

yes it does taper off and i will talk to them about squaring it off. whats the worst case scenario for a situation like this,ie: water issues or actuall structure problems?

NJ Brickie

Personally I am not sold on a keyway if you have rebar in a footing, shouldn't be required. It is considered old school, engineers still draw it as habit but no one can explain why it is still there or needed.[/quote]

You are most likely correct about the keyway in this situation. Just a little insurance that costs next to nothing, if planned ahead.

NJ Brickie

Square it off like chris said. Yes I would think you might have some structural issues in the future. Might be fine but why gamble?

Chris Johnson

If it tapers off you end up with the concrete being too thin, concrete does not bond to concrete so that thinner section will crack and could potentially cause structural damage.

The keyway is spec'd in all drawings I get, I always question why I need a keyway when I have rebar dowels (#5, gr. 60) every 6-8" o.c., some engineers concede and say yes, ignore the keyway, others want it all, so me being lazy I pour and cut it in with a scrap of 2x material just to appease them.

__________________
Chris

roadhouse

its not a long taper, probobly around 45 degrees or a little more so it shouldtnt be to thin. as far as structual, what am i looking at, the footer actually moving seperatly? seperating at the joint? if it moves, is going to crack my basement wall all the up?

roadhouse

also thanks for the replies and info.

genecarp

Are you really a plumber? If you are i will tell you what to do

__________________

Chris Johnson

potentially or theoretically yes, that is what can happen

__________________
Chris

roadhouse

yes i am actually a plumber. for comfort systems usa in syracuse ny.

genecarp

THere is a product made for bonding cold joints, Google NITOBOND, apply the product, as directed, the joint will then be stronger than the surrounding area. G

__________________

genecarp

HERE YOU GO

http://www.scl.co.tt/Assets/nitobond%20ep...pdf

__________________

roadhouse

ill have to check into that nitobond. this hole situation just plain sucks. it seems to me that the footer is one of the most important parts of the whole house. this is probobly going to be hanging in my head for the next 50 years!

genecarp

Rest easy, if you use the nitobond correctly, this will be a non issue. G

__________________