Crack in bricks - result of expansive soils???

[Anonymous]

Posted by: Edwardo (old forum transfer)
27 Aug 2002 02:29 pm

In September 2001, we purchased an approximately 30 year old home. The home is located in northern Alabama. This home is 100% brick with a walkout basement. The front yard is approximately 3-4 feet higher than the back yard, so not much of the basement is actually underground.

The neighbor's house ( brick ) has a large zig-zag crack starting about 15' in from one corner, going to a window that is approximately 5' from the corner.

At the time we purchased our house, there was no crack on it that we could see. We did have the house inspected and the inspector did not detect or comment on any cracks or soil issues. After moving in and meeting the neighbors, we learned that our house had a crack similar to the neighbor's, although it went up two stories. There is a similar crack on the back of the house, giving the impression that one corner of our house has sunk slightly ( cracks are wider the farther up the house they go ). These cracks opened up very suddenly during a prolonged dry spell this summer ( August ).

We learned from our neighbors that this house had these cracks for many years, but that shortly before putting the house on the market, the previous owners "fixed" the crack ( DIY ). He actually did a very good job, at least cosmetically, as one would have been hard pressed to spot the crack until it was pointed out.

I can't really tell what the crack was repaired with, but it might be some form of caulk or some of that concrete crack repair stuff that comes in a bottle.

Apparently, also from our neighbors, our neighborhood has expansive soils. I have noticed a few other homes that have the tell-tale zig-zag cracks.

What options do we have for repair? It would seem that if the soils are truly expansive and expand and contract, it would be hard to make a repair job stick. Who would we call?

Is there any kind of soil remediation that can minimize the amount of expansive soil?

I am not so worried about the house collapsing, but rather about minimizing collateral damage due to leaking and also future resale value.

Although we are in a buyer beware state I can't help but feel that if this is an expensive proposition to get fixed, that we would have some legal recourse.

[Anonymous]

Posted by: Wgoodrich
Posted: 27 Aug 2002 03:40 pm

In northern states we have requirements of deeper footings and wider footing to compensate from the problems you are experiencing. Often times we still have the same problem appear regardless of the added attempt of strength due to the freezing and thawing heave.

IN you case I suspect that when the dry season happened the dirt dried out allowing the footing to settle yet when the earth picks up mosture again and swells the crack may reduce a bit. Problem is the crack will get worse as time goes by.

The house may have been built over disturbed dirt, sink hole type soil, loose soil washing out in the rain due to being in the side of a hill, during construction your builder may have back filled in a manner causing pressure from the dirt and compaction of heavy equipment during the back fill process while the brick and mortor was still green or many other reasons.

To patch as you discribed the previous owner did will hide the problem for a bit of time but the problem will reappear.

To properly repair you crack and cause of your crack you need to discover if your wall is pushing in due to side pressure. This I do not believe your problem to be since you discribed the crack to pass above the finished grade. Just to be sure though look at the crack from top to bottom. See if your crack is in line up and down or if the crack is offset up and down. An offset up and lower crack surface depicts sideways pressure that may have been caused by improper bracing and curing during the back fill process of the building activities. If this is the case you will need to dig a trench allowing the pressure to release from that wall. Then jack up the wall and floor and remove the lower cracked brick or block. Then you will need to rebuild your brick or block to above the finished grade, then brace that entire wall from the inside and let the wall cure. Then seal that wall on the outside. Then back fill partially allowing the dirt to settle against the wall. Once that motor has cured finish the back fill again allowing it to settle. Then do a final back fill. The entire time keep the bracing there to support that wall until that wall is well cured and the ground has settled completely. This should solve the side pressure problem if that is what you have depicted by misalligned portions of that existing crack.

If you have a crack that is lined up leaving a flat wall but a growing crack from bottom to top you most likely have a settling foundation and footing. If this is the case you most likely can remove the finished floor covering and find a cracked concrete also in the floor somewhere from the wall itself and the middle of the basement. If you find this then you will again have to jack up the main floor supporting the house. Then remove the damaged wall again digging the dirt away from the underground portion of that wall so the wall can be rebuilt. Then dig you footing deeper into solid ground and at least as deep as the footing is required in depth by your area whether by siesmic or by soil types. Dig out the floor to the crack then further by about 2'. Then insert metal reinforcing rebar wired together in a grid not only in the length of the new footing but in the floor also. Then repour you concrete footing and flooring as a unpour all at once making sure you have a thickness of at least 4 hopefully 5" thick in the floor area with a footing pad of about 2' to hopefully 3' if you have a loose soil condition under that new footing. Once that footing and floor has been repoured then rebuild the wall to above finished grade and again brace the underground wall from the inside thoroughly again doing a partial back fill again a back fill and again a finish back fill all the time leaving the braces to support for any side pressure while the dirt is settling in. Once the dirt has settled and hte wall has cured allow the few inches of the original wall jacked up to be allowed to settle back to the new replaced wall. Then about a year later as long as this repair has held you can saw out the mortor of the crack left above ground of the original crack left and do what is called a tuck point of mortor worked back into the place of the old mortor that was sawed out. The strenth of hte new wall and footing with the rebar re-enforcement should solve you settling problem.

You can say wow that is a lot of work but if you are carefull you can do it with rented equipment and some advice from others as you do the job. Then you have a stong house again of value.

Without doing this work as discribed above over time the condition will worsen and eventually a portion of that wall will cave in or out and then you will have to do the repair. Problem with waiting is the longer it goes on the more damage you will experience both by the settling during the damage being done and the jacking up of the few inches as the repair is being done.

While jacking the wall you may create a crack or two or some damaged drywall duing this jacking for repair process. As the house is let back down the cracks created will settle back as they were and minor repair will correct these cracks with patch material. At least then you have a solid foot print and should have no more damage.

Often times if rebar re-enforcement and compaction of loose soil were done when the original building process was done this problem you have now could have stood a good chance to have been prevented.

You said you have a buyer beware state. Yet you also said you hired your own home inspector before buying that home. A patched wall even when done well can be seen on most occasions. Before you do anything ask for a few expert opinions if this settling problem was evident when the home inspector made his report. If you have expert opinoins such as engineers to state the home inspector should have reported and seen the footing and cracked wall problem then you may have civil recourse holding that home inspector liable. May be worth your consulting an attorney on the subject for you own peace of mind.

Let us know how you come out and good luck

Wg

[Anonymous]

Posted by: guest
Posted: 27 Aug 2002 04:25 pm

Thanks for the quick response!

The main two cracks are:

1) In the middle of the side wall of the house ( house is two rooms deep with bathroom between the two rooms ), starting at ground level going almost straight up to garage window and continuing almost straight up to upstairs bathroom window ( which is directly over garage window ). There is some zig-zagging, but the crack is mostly straight up either following vertical mortar joints or passing right through bricks. The fill on this side of the house is minor ( 0 at back, 3 or so feet at front, probably 1-1.5 feet at crack ). There is a crack on the garage floor that goes to the wall right the crack is. There is also a crack in the driveway expansion joint ( the thing that is supposed to direct cracks where you "want" them ), which matches up exactly with the start of the crack. Inside the brick is cinder block which is not directly visible because the garage is finished with drywall. This crack pulls the brick away from the right side of the window ( as you are facing it ).

2) Between the two garage doors on the back of the house. If you turn from the street onto our driveway, our house will be immediately to your left. This is the wall described in 1). When you get to the back of the house, you can see that the two garage doors are on the side of the house closest to the driveway ( left side as you face the back of the house ). There is some evidence of repaired crack between the garage doors, but it really opens up ( probably to 1/4" ) between the garage doors and an upstairs window. This crack is also mostly vertical, following vertical mortar joints or passing right through brick, splitting it. The brick has pulled away from the left side of the window ( as you face it ), leaving a gap of 1/2+ inch.

I anticipate that we will have an engineer come out to look at it. Ironically, the guy we originally hired as a home inspector is also listed in the yellow pages as a foundation engineer and as a structural engineer!

[Anonymous]

Posted by: Wgoodrich
27 Aug 2002 10:57 pm

Imagine a bad settling of the earth below your house foot print the house sets on that earth. Imagine you house breaking off and falling due to the settling of that earth. This is what you are discribing as to what is happening. Almost reminds me of the mud slide problem in California years ago where the used fill dirt to extend a housing developement beyond where the clif was originally. They brought in huge amounts of fill dirt and used sheep foot compactors and filled as high as 20' of fill dirt and higher until that clif was extended out enough to build another row of houses. Decades later the houses slide off the hill or cliff due to huge movements of muddy fill dirt that was installed decades before where the houses were set.

In you case I suspect there was disturbed dirt below the house and there was no on not enough re-enforcing rebar in the concrete or / and the concrete was not thick enough to span the loose or disturbed dirt if settling occurred. Then when the dirt settled the house cracked and that portion of the house has created the crack you see on both sides of the house and a crack in the concrete floor located from crack to crack.

To confirm what I am suspecting take a 4' level and place on the floor where the house is known not to be settling [larger portion of the house that you believe has not settled. Then move the level to the floor area beyond an imaginary line from wall crack to wall crack. Look at the bubble on the 4' level in both the unmoved portion of the floor and the settled portion of the floor with or without carpeting. If you placed the 4' level on the smaller suspected settled part of the house perpendicular of the expected crack in the floor from wall crack to wall crack I suspect you will find a major difference in that bubble showing the floor is out of level in that sinking section of you home.

I believe you house was built on either fill dirt, or you experiencing a washout of dirt from under you footing of that house.

Let us know what you engineer has to say. Be sure to call an engineer known to have a strong reputation for his skills in the field. Also wouldn't hurt to ask to see his engineering degree to confirm you are talking to a certified engineer.

Good Luck

Wg