Russel Ray is a very professional, knowledgeable and experienced home inspector from San Diego CA and fellow Active Rain blogger. Over the last while, he has written a series of posts on the subject of cracks in a property. If you have a crack and are unsure of the impact on your property, consult with a professional, such as a structural engineer, however, as a primer, and to gain general knowledge, I have found Russel's information very helpful. This is Part Nine of the series and discusses the possible effect on a structure of a cycle of wet and drying clay soil...
Here a crack, there a crack....
DISCLAIMER: This discussion is based on several decades of experience in real estate, including as a home inspector and general contractor. I am not a licensed structural engineer, so if you are not comfortable with cracks and our discussion here, hire a structural engineer to help you. This discussion, however, should help you be a little more knowledgeable about cracks so that you don't just automatically assume the worst. Cracks happen, kind of like ActiveRain blogs.
I'll presume that you have read previous lessons.
So far, we've discussed
- curing and shrinkage cracks in the foundation stem wall in the garage (Lesson One and Lesson Two),
- cracks in the garage floor (Lesson Three),
- cracks in the foundation stem wall of the house proper, the living area (Lesson Four),
- cracks in raised foundations with crawl spaces (Lesson Five and Lesson Six),
- water (Lesson Seven), and
- stucco cracks (Lesson Eight)
In many parts of the country, the makeup of the soil is critical to the structural integrity of the home. After all, the home has to sit on the soil, so if the soil hasn't been prepared properly and allowed to settle (or had some huge, monster compacting machines working on it), as the soil settles, the house will settle too, creating various cracks.
As with all cracks, the location of the cracks, as well as their size, width, and displacement, can tell us a lot about what is going on.
Some people believe that a home on a raised foundation, especially one with piers and beams like my wise old grandmother's house in Kingsville, Texas, will be subject to fewer settling cracks because there isn't as much foundation to settle. However, if one part of the foundation does settle, there's not much secondary support from the rest of the foundation like there would be in a concrete slab-on-grade. I have no opinion one way or the other because I've seen the best and worst in homes with raised foundations and in homes with slab-on-grade foundations. Rather than making summary statements of which type of home is better, it might be better to simply ensure that the foundation soils are prepared properly to begin with.
In the following picture, we see lots of large cracks in the soil.
That happens to be at a home built on a raised foundation that I inspected many years ago. Those cracks indicate a dessicated clay soil.
A dessicated soil means that it is dry, very dry, and clay soils are expansive. Soils will shrink and contract as they dry. As the structure accomodates the drying soil — by settling and cracking — the potential for more significant cracks increases because when the rains come. A dessicated clay soil has the potential to absorb a significant amount of moisture, up to about 35% moisture content. As the soil absorbs that moisture, it expands, causing additional damage to the house. Obviously, if this goes on regularly over the years, the house could be a total disaster after twenty or thirty years.
If you go watch the soils being prepared on a new home being built in an area of expansive clays, you'll usually find the workers spreading tons of lime in the soil and then compacting it before laying the foundation. Lime is a great additive for stabilizing expansive soils like clays.
Here in San Diego County, there is a large pocket of clay soil that affects quite a few homes in many luxury areas, such as Black Mountain Ranch, Carmel Mountain, Fairbanks Ranch, Poway, Rancho Bernardo, Rancho Santa Fe, Sabre Springs, and Scripps Ranch.
Many of the older homes in those areas do have settling cracks in them. Many of the newer homes are using advanced technology to help prevent settling cracks, especially around doors and windows. For example, if you find a home that has various accoutrements around the doors and windows, like in the following picture, that usually indicates that the windows have been framed to help distribute stresses along the length of the accoutrement rather than at the corners. It will be rare to find stucco cracks at door and window corners here.
Unfortunately, that type of work is labor intensive, so it increases the cost of the home, which is why we only find that kind of work in the high-end subdivisions, and quite often, it's only done on the front side of the house. The other three sides are often ignored. I guess it has something to do with curb appeal.
Twenty most recent posts
- The Music Chronicles of Russel Ray — Just a bunch of fluff
- Flower Fiesta — Flowers for Easter week
- Pay It Forward — Just a spoonful of sugar helps the Google juice go down....
- San Diego Home Inspections — Here a crack, there a crack (part 8)
- I've had it!
- San Diego Home Inspections — Here a crack, there a crack (part 7)
- Nature Handbook — Handle with extreme care
- Opinion — Why did we change?
- The Music Chronicles of Russel Ray — Martha, My Dear!
- Picture of the Moment by Russel Ray Photos — Picture of the Moment - How to sneak up on a sleeping cat
- Picture of the Moment by Russel Ray Photos — I wasn't even out in the boondocks!
- Halls of History — You little tramp!
- San Diego Home Inspections — Here a crack, there a crack (part 6)
- Flower Fiesta — How do they know when Easter is here?
- San Diego Home Inspections — Here a crack, there a crack (part 5)
- Pay It Forward — Pay It Forward - Donors choose, and I chose photojournalism!
- San Diego Home Inspections — Here a crack, there a crack (part 4)
- San Diego Home Inspections — Why is E&O insurance so high?
- San Diego Home Inspections — Here a crack, there a crack (part 3)
- Halls of History — What did 627,000 people accomplish?
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Chris Smith CSSBB
Chay Realty Inc., Brokerage