Crack in slab. Contract pending on house.

[themeanies]

I can't imagine this is a rare problem, so if there is a better place to research this please feel free to direct me elsewhere.

We have put a contract on a house and the inspection uncovered a crack in the slab.

The home is 5 years old built on what used to be a cotton farm. The area is now suburban with paved streets etc. The house is in a very dry climate with temps ranging from 25-105F annually.

The crack in question is approximately 25 ft long and travels under two walls. 4ft of the slab is exposed in the garage and the other 21 ft are tile in the kitchen. The grout in the tile is cracked. The crack does not seem to travel from one side of the slab to the other. The outer edge of the slab is approximately 10 feet parallel to this crack. There is what I assume is some very small shifting of the door frame into the house from the garage. This door is perpendicular to the crack and between the crack and the outer edge of the slab. Most of the rest of the home is carpeted and I am unable to see any other telltale signs in door frames or walls. The home is about 2 feet above the surrounding street and it is possible that this crack is from settling. I do not yet know how long it has been there or if it has been looked at professionally. The overall quality of the home is outstanding. High quality building materials were used and the builder has a great local reputation. The finish out is medium quality. There are no water lines involved as all water delivery is run through the ceilings.

A picture of the exposed area can be found here:

So questions.

1)Is this a deal breaker?

2)Should I look into stabilization?

3)What is likely to happen to this in the future? We plan to stay in this home for a long time.

Any other comments are greatly appreciated.

tM

[Italian]

YES,YES,YES,YES,YES,YES. And here is why there are litterally dozens of reason why this could be happening so of which are not to costly others would break you stay away from it-------even if they lower the price......

themeanies wrote:

[bigjim]

[Speedy Jim]

Doesn't look toooooooo bad...

You've answered the query about water lines. But you can bet that the kitchen drain (at the very least) is buried in/under the slab.

Since the kitchen tile is already compromised, maybe factor into the price a demo of the floor in that area and a re-tile.

If you like the house enough for other reasons, do what you gotta do...

Jim

[EXT]

I notice the crack is wider at the top/surface than it is at the bottom of the slab edge. To me this says, and can be checked with a straightedge if the concrete is reasonably level and flat, that the outer edges have settled or expansive soil has pushed up in the middle of the slab.

Without knowing the building design, I would assume that the bulk of the weight of the house is on the outer walls, hence causing the outer edges to settle a bit. The middle of the slab being supported on compacted fill or some concrete piers within the fill. Without much weight on this area it probably would not settle much resulting in the type of crack you are looking at. I would assume that the crack is still forming and will probably finish traveling across to the opposite outer wall.

The crack does not appear to be very wide, and probably not get much wider, but I cannot forecast that, only an engineer who checked the construction plans and is familiar with your form of construction may be able to estimate what will happen in the future.

I have seen a lot of concrete cracks, most are not a problem, and cause little concern. You may have to regrout the tiles, possibly using something flexible until all has stabilized. You may want to build into your price, any expected future repairs.

[No]

Not a deal breaker in my opinion. It is often said that there are two types of concrete... concrete that is cracked and concrete that will crack. This is not a deal breaker in my opinion. Worst thing is the effect on the tile. You could just re-grout the tile and cross your fingers and re-grout again in a couple of years if necessary. Thats the cheapest and easiest thing to do. The house wont fall down.

[dpb]

alt.building.construction is an alternative location

With the bare slab in the garage, I don't think it took much "uncovering"... :)

You don't say... :)

For five years, what appears to be no more than a hairline crack is certainly not unexpected--it would be more unusual for there to not be any.

I think the "NO!" crowd here are over-reacting given the (apparent) size of the crack and minimal apparent movement. I don't see the "wider at the top/surface than it is at the bottom of the slab edge" of another poster -- given the perspective the size of the crack looks essentially the same over the exposed length to me. It's hard to tell and I suspect it is mostly owing to the camera lens and angle but to me it appears there's possibly a high spot in the baseboard over the crack indicating a settling on one or both sides of the crack location. That, of course, would be very easy to check w/ a straightedge/level. Assuming that isn't real and significant, I'd not have too much reservation although it would certainly be prudent to get it looked at and to build in at least some discount in the price to account for some perceived risk.

You say it's a dry area but was farm ground previously--was it irrigated or dryland? The most likely probable future problems will undoubtedly be if it's an area that does have some rainfall and can have "wet spells" where the soil dries out between rain events. Ensuring good drainage away from the foundation on what is probably a very flat lot is also key.

[Edwin Pawlowski]

I'd want to know how long it has been there, and has it moved since.

I have a similar crack in my lower level slab. It has been there for 25 years and has not moved. If yours is a similar situation, no big deal. Do some checking, but I doubt it is a deal breaker.

[Not Avaiable]

dpb wrote: ou don't say... :)

This is true. Before I finished my (then) 5 year old basement, I had 6 or 7 cracks, mostly hairlines. A couple are almost 1/8". Additionly, I had cracks of 1/8" or more at all the joins. I covered those cracks with roofing felts, and put ceremic tiles on. No more cracks visible.

I visited 4 of my neighbor's basements. All of their slabs had cracks before put on a finished floors (they put laminates on).

To those who said that cracks are bad signs, maybe you can remove your carpets or laminates and report back about your results.

[The Reverend Natural Light]

I wouldn't be worried in the slightest over that crack unless it just showed up or the floor is tilted at either side. Use a straight edge and a marble to make sure everything is flat and level and then forget about it.

It's near impossible to pour that much concrete without a crack or two. Too bad about the tile in the kitchen. There are ways to lay tile over a crack so it won't come through, should you decide to replace it.

-rev

themeanies wrote:

[The Reverend Natural Light]

I wouldn't be worried in the slightest over that crack unless it just showed up or the floor is tilted at either side. Use a straight edge and a marble to make sure everything is flat and level and then forget about it.

It's near impossible to pour that much concrete without a crack or two. Too bad about the tile in the kitchen. There are ways to lay tile over a crack so it won't come through, should you decide to replace it.

-rev

themeanies wrote:

[DanG]

Anytime concrete is 12 feet or more in any one direction, it will crack. That is the reason for saw cut contraction joints, tooled contraction joints, and true construction joints. Most residential floor slabs are not jointed. They will crack. This is just as true on a huge commercial floor, a highway, or a sidewalk. I suspect the crack was there before the ceramic floor. IF the installer had seen the crack, he should have used an isolation sheet like Dutra to bridge the crack or installed an expansion joint in the tile.

I would not let the crack influence my decision. Consider the cost of the advice. ______________________________ Keep the whole world singing . . . . DanG (remove the sevens) [e-mail]

[hallerb]

probably best to get a structural engineer look at it.

just on the off chance its serious

make sure no mining has occured in your area....

[Michael Daly]

Better to get a soils and foundations engineer. After five years, it should have settled all it's going to, but some soils will settle for a long time. A local soil/foundation expert will know if there are problematic soils in your region. You might get all the info you need with a phone call.

Mike

[J.A. Michel]

Looks normal to me. Concrete cracks, there's no way around it. I have a brand new house, with poured concrete basement walls less than a year old. Some hairline cracks have appeared in the walls and floor. This doesn't necessarily mean that it's a problem. Deal breaker? No. Price negotiation tool? *YES*