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Cracking puzzle - UPDATED with pictures and links


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Who is the expert I need to seek?

My cousin called me and asked if I could take a look at her house. She said there was a crack in the wall she was concerned about. Well when I got there, there was a crack in the drywall along the seam vertical from the corner of the window going to the floor. On the other side of the window there was another smaller one, it reached about half way to the floor (maybe 8 inches). The window opens freely with no binding. Well I looked around the foundation on the house and one corner the cinder block was cracked diagonally and the lower corner separated and sagging a bit. Along the foundation at the back of the house, same side, there were several mortar crack repairs made but it looked like all the cinder blocks were in place. Along this side of the house, onto which two gutters (at front and rear corner) drain, the ground has formed an almost V cut trench. The difference between the top of the V where the foundation is and the bottom is a good 18inches at maybe a 30 degree down angle. They report that during a rain storm, there is a good flowing river there. BTW, this trench goes to the sidewalk and on top of the street gutter opening. Also of note, there is a large partially exposed root system between the top of the trench and the foundation edge.

I went back into the house and looked some more. At that front corner where the cinder block is cracked and sagging, the closet door binds and will no longer close. Also a bathroom window and spare room window along that side also bind but will move if enough pressure is applied. Also next to that corner but on the front of the house is a large sliding window. A crack extends from the top corner of the window horizontally to the wall and about 2inches from the wall takes a 90 degree turn up. It appears to be a stair step crack forming, but there isn't enough wall left to do it. This window does NOT bind and moves very easily. Of course, this window and the other front window for which I was originally called were installed maybe 1 year ago. The door and windows that bind are original or at least over 11 years of age (they bought the house 11 years ago).

So then I went into the attic to look for problems there. All the trusses lined up properly. I didn't find any signs of extreme compression or cracking. The attic, except for the bathroom exhaust venting into it, looked just fine. The roof had no sagging or other signs of problems. Back down stairs I used a level to check several spots along the floor including right at the corner with the crack, and all was good.

Now, this is more than a home inspection because it was family asking for help. It is also a complicated puzzle to find the exact cause of the cracking walls. I think the foundation is slipping, or has slipped into that trench as it grows bigger. The exposed roots I believe have actually helped to prevent more damage.

I'm thinking that backfilling the trench then addressing the drainage problem, maybe with a French drain, should prevent further damage. Then if so, just repair the cracks and live a happy life.

My question is this. Who would I call for the next step to confirm my thoughts and suggest a repair? Of course the first experts are here so I'd like to hear your thoughts.

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I don't know about the rest of the guys here, but that got a little hard for me to follow without photos to illustrate. So, pending the posting of some photos, I will limit my comments to the following:

1. Most straight line cracks in drywall are usually harmless -- be they vertical or horizontal. Most often, they are just the result of normal drying/shrinkage or compression of the framing members. Wood moves; drywall doesn't like to. These types of cracks may be unrelated to the problem at hand. Diagonal or stair step cracks in drywall likely indicate potentially more worrisome movement, especially in a newer home like this.

2. I think I know you well enough to know you won't take offense at this...PLEASE don't use the term "cinder blocks". Maybe it's just me, but that grates on my ears as badly as people saying "masonary" with the extra "a". Concrete blocks is more appropriate. If you want to really engage in construction speak -- and I don't advise that as it will only confuse laymen -- call 'em CMU's. (Concrete masonry units.)

3. Concrete blocks can show stair step cracking due to normal expansion/contraction cycles. This is not the same as with brick veneer where straight line cracks are generally from routine expansion/contraction and stair step cracking is generally indicative of differential settlement.

Clear as mud?

Throw some photos at us and maybe the situation will be clearer.

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John, I guess I'd have some more questions first.

How old is the house? How much, if any, reframing did they do a year ago when they put in the new windows? Did the new window get a proper header? Is the grading at that side towards the house and/or is the trench supposed to be draining the back yard? Or, is it just the gutters causing the "river"?

"Who would I call for the next step to confirm my thoughts and suggest a repair?"

I realize this is family but I'd be careful about diagnosing this too much further. Obviously, you have some drainage issues and if you didn't have suspicions about the foundation, I'd recommend a drainage contractor. In this case, with the old CMU repairs and the "sagging" bit, etc, etc, it sounds like your cousin needs a well qualified foundation contractor for a full and professional evaluation of the existing foundation and underlying soil and to design improvements or repairs, including the drainage.

I'd stay involved for the education and to, perhaps, prevent the contractor taking your cousin for a ride, but you may have done all you can already.

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OK, first off I got a structural engineer coming over middle of next week to take a look. I met this guy at a networking meeting and we had lunch and talked. Like I have done with other contractors, he is providing me some hands on training and agreed to help me with this puzzle. But anyways, here are some pictures and maybe a better explanation. What ya think?

Front view of the house, you can see the erosion that has taken place creating the small gully on the left.



A close up of the corner.



Rear corner same side


http://img231.imageshack.us/img231/7035 ... nergw8.jpg

Here is the side.



This is the front door, notice how it doesn't quite fit anymore.



I'm not sure if this was added after the house was built, but it doesn't look right and may be another indicator. Notice the distance from the siding to the cement at the front then again near the door. Also I poured some water on it to see the slope. Near the front it flows away but at the door it pools. Something is not in kilter here but I can't make it out.


http://img206.imageshack.us/img206/4609 ... rchiy9.jpg

There are three windows at the front of the house. From the corner with the problem it goes to the right, Window, porch with front door, window 2 and window 3.

Here are two pictures of window 2.

This is the one that started my cousins concern. They put some clear tape on it and used a sharpie to outline the crack to see if it is moving/growing. It's only been a few days and no change so far.



The other side of same window.



Window 3 has a small crack, I don't think it's related but I added it anyways.



Finally this is the bedroom on the corner. There is a crack in the top corner, the closet door doesn't close, and the window in the bathroom won't open.



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I'll take a stab at it. However, this is just guesswork. No way would I diagnose a problem like this w/o a site visit.

Anyway, I suspect that the area you believe has eroded is the original grade, or close to it. It looks like there was either a pad built up that the home was built on, or there was soil added after construction to cover up the foundation better and improve drainage away from the home.

If there was a pad prepared prior to the footing dig, it's possible that the dirt was not compacted properly and the footing was placed on soil which has since settled.

But here's what I find curious: It's hard to tell, but in the photo labeled fcornerpw6, it looks like there is a concrete perimeter block on the left side and poured concrete (monolithic slab) adjacent to it to the right. The slab appears to key on the perimeter block on the side but rest on soil to the right, across the front. Is this correct? If so, that's wrong. The bottom of the concrete shouldn't be sitting just on top of the fill. It should at least be below the frost line and not visible. If it is resting on the dirt only, you could be dealing with frost heave, shrinking/swelling soil due to moisture changes, or differential settlement from improperly compacted soil. Possibly elements of all 3.

Is this the original construction, or was some remodeling done? If so, when and what?

In any case, it doesn't look good. Let us know what the engineer says.

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Originally posted by AHI in AR

But here's what I find curious: It's hard to tell, but in the photo labeled fcornerpw6, it looks like there is a concrete perimeter block on the left side and poured concrete (monolithic slab) adjacent to it to the right. The slab appears to key on the perimeter block on the side but rest on soil to the right, across the front.


I thought that looked a little odd too. I wish I could see a photo of the entire property from all angles so that I could get a better idea of the site - those are called "establishing" shots, John.

With such a limited view of the foundation to make a determination, it's hard, but it looks to me almost like you might be dealing with a portion of the home that's been converted from a garage to living space and that concrete is where they added a little concrete stemwall to support the front wall where they filled in the overhead door opening with studs. I see those all the time around here. If that's the case, there very well could be some settling issues; I've seen settled garage floors many times.

There are all sorts of possible causes for a garage slab to settle but the most common one I can think of is impatience. Some builders will store all of their crap in the garage on the dirt floor during a build and don't bother to place the slab until the very last thing. When that happens, if they're impatient, and don't take the trouble to carefully compact the soil that's going to be beneath the garage floor slab, the slab can settle.

My mother just moved to Florida from Virginia Beach last year after living in VB for about 15 years. Her sister and my cousins have lived there for half a century. The first time I visited VB, I noticed that once you are through the top soil the soil beneath is very sandy - almost like beach sand. Once, i noticed a pipe projecting from the yard in my mothers back yard and asked her what it was about. She said it was a well pipe so folks could hook up a pump and use groundwater to irrigate their lawns. Apparently, the water table is so high there that it's possible to do so. Compared to some of the drainage and erosion issues I see around here, what I see in that photo is a cakewalk. I think you have to be more concerned with what the footer has been placed on and what kind of drainage exists immediately next to the footer.

My opinion, worth what you paid for it.



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