Cracks in Foundation Wall

[Digger1799]

I have a 3 yr old poured concrete foundation with 3 steps in the wall. I got a crack in the first step within months of it being framed. Now that wall has a crack (full lenght) at evert step. The opposite was has one at one step.

The floor cracked a littel the first year and has increasingly grown to more cracks each year. Now I noticed that I have un-even floor heights at two of the cracks.

I am looking to install some kind of crack monitor to see just how much this house is moving.

 

[apetr26542]

Spacing of these cracks?How wide? How much is uneveness at floor? You mentioned the opposite wall has one also, does this crack go end to end? Could be settlement, some settlement is natural. The steps in the wall created a discontinuity and likely started out as shrinkage cracks. The crack was likely always there, just not visible, creating a weak plane, now that some settling may be occuring, the existing cracks are getting wider.

My house is going on 7 years old, I've noticed the same cracks from day 1, or month 1. The seem to open a little close a little, you could stick some toothpicks loosely in the cracks, if they fall out, then you know they are moveing.

 

[apetr26542]

I did an inspection of a residential home, had a good size crack in the wall, the home owner had filled it with silicone. The wall closed up and sqeezed it out over time. Just so you know. Every residential concrete foundation I've seen has always had cracks. Is there any reinforcing steel in the walls?

 

[bjb]

The steps are natural places for the concrete wall to crack because you have a stress concentration at the step. Also, residential concrete typically has almost none to no horizontal reinforcing in the wall, and no control joints in the wall. Residentail construction is quick and dirty. The subgrade/subase under your slab may have been improperly prepared, the native soils may be problematic, etc.

Also, the quality of concrete, and the construction practices for residential concrete are typically poor. Your slab probably went in with a high water cement ratio, which can result in a slab which is prone to curling and excessive shrinkage. It is possible that the un-even floor heights are the result of slab curling. Do you have any joints in your slab? Your house may be moving, but it is also possible that relatively low quality concrete is also the reason.

 

[Digger1799]

I will be up at the home in two weeks. I will shoot some pics and take some measurements. I know these not your usual settling cracks for two reasons. First: I am in construction and am quite familar with what is "normal" and what is a potential nigthmare. Second: These cracks have multiplied, grown or increased in distance unequally. I was always taughht that a crack that is wider at the top than bottom shows movement.

The other thing is that the cracks in the floor seem to deliniate a specific area of settlement. Everything forward a a specific point is cracked, everything behind it is not.

Though I was to supervise the pour, I was hit by a car and spent that month in rehab. I speced if I remeber corrctly #4 rebar in the footing and #5 in the walls (or is that backwards). Horizontal rebar was not speced, but my local masons always did it, my fault, maybe, as I was working outside of my area and was unfamilar with there job or practices. The footings were to to be 10" x 24" and I remeber them complaining about that. They said it was overkill and I insisted they do it this way, but again I was unable to watch it. Same thing with the footings and slab pour. I always require plate compaction prior to forming the footings as well and plate compaction ever 6" on the floor.

I was thinking that maybe they did not compact it or maybe it is simple that the front in settling a lot as the back 1/2 of the house is on a blasted out rock ledge.