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My one year old placed concrete foundation has a diagonal crack running down from a corner formed where the 4′ high wall for a walk out section meets the 8′ full wall. The crack runs 1/8″ wide at the top to nothing at the floor line.
There is also a 12′ long, 4′ high retaining wall running out perpendicular from the low concrete wall section.
Plenty of grade and drainage; no water problems.
Fairly certain the excavation wasn’t overdug and 1 1/4″ stone under everything with half the foundation on ledge. The excavator did bounce a stone off the wall when back filling (don’t get me started) but pulled it out of the way.
I’m thinking it’s just shrinkage as there are no other cracks anywhere and thought of boring a 3/4″ hole through the crack and running a threaded rod with nuts, ,lock washers and 4X8″ plates on either end sealed with epoxy.
If I could get an engineer to return my calls I’d have it looked at but what does everyone think about my inexperienced remedy? Suggestions?
Replies
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Why wont the engineers return your calls? The ones I've dealt with love to talk on the phone. I suspect that's how they avoid working. They have some of the best stories.
JonC
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Do you have re-rod in the walls?
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It could be that the section of foundation that is not on ledge settled- was the stone compacted before the foundation was poured? If it wasn't and there is no rebar in the footings and/or walls, that may explain it. I've used hydrualic cement(WaterPlug and QuikRock are two brands) to patch foundation cracks. I'd still try to contact the engineer.
*Since I dont spend alot of time on the phone, and I dont have very many good stories, you may want to look elsewhere for advice. But, I am an engineer, and holy cow, a residential contractor as well. JonC...you'd love me. From your description the crack indicates settlement not shrinkage. My advice would be to monitor the size of the crack to see if it is growing in width. Your foundation is new, and all things remaining equal, settlement will diminish over time. Once you are confident the crack isnt growing you can patch it. In addition to having an engineer come look at it...where's the foundation contractor and the GC? What do they say? Dave
*Two kinds of concrete:Concrete that is cracked.andConcrete that hasn't cracked yet.Drilling holes through it and bolting wood and epoxy sounds pretty un-engineered. Besides if you try and fix it yourself you assume some of the liability for any problems here. 1/8" isn't much but, trust your instincts and call back the responsible contractor. Responsible contractor huh, kind of an oxymoron like military intelligence, jumbo shrimp, etc.joe d
*Hi, just another run of the mill engineer with a good story!!!I assume the plates you refer to are just to keep the walls in alignment not to prevent the crack from widening. In this case I would still consult an engineer to check the right gauge of steel for the plates and number of fasteners to resist the lateral forces exerted by the wall.I agree that the crack could be from settling. One end of the foundation on rock and the other on dirt. Sounds like a recipe for a crack. Another possibility is shrinkage of the soil. I have this problem with my house. I had soil borings done and an "attenburg" or "atterburg" (sp) test done on the soil. This measures how much soil with shrink and swell with changes in moisture content. If it was fairly wet when the foundation was poured and then dried after backfilling, this could cause the soil to shrink and cause your crack. If you don't have furhter moisture problems then the crack shouldn't get any worse. If the crack gets bigger and smaller in different seasons it's probabley shrink/swell. In this case there is nothing you can do except fill the crack. There are some contractors who fill foundation cracks with a urethane sealant that remains flexable while sealing the crack.Hope this helps.Tim
*Flash,Contact your local concrete construction supply houseregarding two part epoxy injection. They will usually rent the applicator. Very strong repair and cost effective. Strong fumes for a few hours.Food for thought, Rick
*All this repair advice is great if we can determine; 1. the cause of the crack, and 2. If the cause was settlement it has dimished to a negligible level. If it isnt settlement then repair it now with one of the methods mentioned above. (I'd vote for something elastic.) If it is caused by settlement, and its still moving, you'll just be repairing it again next year. Out of curiosity....who's paying for this repair?Dave.
*............if you get to the repair part. check out Abatron (????) they usually run an add in some of the Restoration mags....they make prepackaged repair kits with plunger/ mixer applicators...have used their product for crack repair on a garage slab...I was impressed... we didn't have any local supplier that I could find... so they shipped the stuff fast..
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Thank you all for the responses!
Let's see if I can shed more light.
The GC, concrete contractor and excavator are doing a Three Stooges routine like you wouldn't believe. I'm just glad I'll never have a water problem where the crack is due to the severe grade!
While I paid for re-bar in the footings, I couldn't be here to see it before the pour so I'm trusting the inspector.In the walls?...I'm not confident on that at all.
The stone was compacted but I'm also leaning toward "jcallahan's" and Tim Daniel's thought of the footings half sitting on ledge and the other on the stone.
JoeD is absolutely correct in "two kinds of concrete"!
I 'd like to ad that I'm not expecting perfection from people, technologies and materials which don't posess it to begin with, but this has been the WORST experience of my life! (Well...there was that first marriage and the trip to SE Asia)
From the ledge to the ridge vent I've heard more lame-ass excuses for things NOT being square, plumb and level I could write a book were it not for trying to forget I ever heard them! (breath in slowly...out slowly)
There's just too much money out there. Anyone with a hammer and three friends who'll lie as references are giving true craftspeople a black eye.
Were it not for the location of this house I'd dump it.
ANYWAY...who's a good Structural Engineer in CT?
Any references? :)
*Flash, Sounds like you are having fun! The reason I asked about the re-bar in the walls is that I don't think you have much to worry about if you have horizontal re-bar in the walls. Almost all poured concrete foundations crack at a junction like you have or crack at the edges of the window openings. The main reason is usually that they have watered down the concrete so much that it simply shrinks and that is the natural weak point. A 1/8" crack is a pretty good sized crack and is not your typical shrinkage crack. You have a classic setup for a footing crack because part of the footing is sitting on something absolutely solid (rock ledge). I don't care how much you compact the other material, it is going to settle and you will probably get a cracked footing. You probably have a combination of the two problems. Many times, horizontal reinforcing in the walls will hold the whole structure together and not allow this to happen. I would find out for sure if you have re-bar in the walls (both horizontally and vertically) If you don't, you have been shafted. Don't you have building inspectors that check this before they pour the walls?? If you have no rod, I think it would be a good idea to get someone with knowledge of concrete walls to evaluate what you have to do to stabilize and waterproof the wall. You will certainly need to dig up the backfill down to the footings and thoroughly waterproof it to make sure that you don't get water entering the inner parts of your wall from rain or whatever. This is a good example of why a person building a new home should at least familiarize themselves with the basics and make sure that each stage of construction is done to spec. In this day and age, and with the costs of new homes, you really have to assume a lot of the responsibility for monitoring your own projects.Good luck!!
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My one year old placed concrete foundation has a diagonal crack running down from a corner formed where the 4' high wall for a walk out section meets the 8' full wall. The crack runs 1/8" wide at the top to nothing at the floor line.
There is also a 12' long, 4' high retaining wall running out perpendicular from the low concrete wall section.
Plenty of grade and drainage; no water problems.
Fairly certain the excavation wasn't overdug and 1 1/4" stone under everything with half the foundation on ledge. The excavator did bounce a stone off the wall when back filling (don't get me started) but pulled it out of the way.
I'm thinking it's just shrinkage as there are no other cracks anywhere and thought of boring a 3/4" hole through the crack and running a threaded rod with nuts, ,lock washers and 4X8" plates on either end sealed with epoxy.
If I could get an engineer to return my calls I'd have it looked at but what does everyone think about my inexperienced remedy? Suggestions?
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b flash
Sorry to hear of your dreadful experience. You couldn't be more correct with regard to considering sources of information or in this case references. The Three Stooges told you to call the Keystone Cops and Luarel & Hardy who gave raving reviews of Stooges work. What are you going to do. More names. I don't need to tell you this now.
I've poured many miles and many cubic yards of concrete here in Terra-shaker country and to keep the concrete from cracking many elements and proceedures must be followed to a tee to bring it all together.
The discription was a little difficult to follow, however I do understand you have a crack. You have recieved some sound advice already, I'd like to affirm the documentation route. Besides contacting via certified mail all envolved to make sure they are aware, might be a good idea to get an engineer involved to begin tracking the movement of the crack. Are there any photos of the foundation while under construction? Given the amount of concrete placed, was the foundation area tested by a soils engineer to determine whether it could handle the new load.
You do not appear to be too concerned with moisture penetrating, was the back side of the wall sealed or protected with some form of a water stop?
Out here rebar is everywhere in concrete construction with very tight tolerences. And for the right reasons. Even in your area I don't understand why some contractors choose to exclude to save a buck.
Have the drawings examined by the new engineer to find out which stage of the operation may have been negleted which leads to your current problem.
Uncompacted soil. Lack of rebar or improperly placed rebar can be just as bad. Bad batch or wrong mix of concrete in the walls. (Different mixes for different compressive strengths) Concrete was either not vibrated or over vibrated.
Sure hope you can get those contractors to stand behind thier work and cooperate with you.
Talk to Moe, it seems he keeps the other in line.
Just one man's opinion.