We're having a general discussion about various types of cracks in our homes and on our properties. If you're not comfortable discussing cracks -- whether home inspector, Realtor, seller, or buyer -- hire a professional to help you. This discussion, however, should provide you with some basic knowledge about cracks and why they happen so that you don't automatically assume the worst. Cracks do happen, just like Active Rain blogs.

Lesson Six

Read previous lessons here.

Music for your reading pleasure

"Ireland's Call," Celtic Thunder

Before continuing, click here for your chance to win a $25 gift certificate.
It's fun, very easy, and you don't even have to leave Active Rain.

So far, we've discussed

1. curing and shrinkage cracks in the foundation stem wall in the garage,
2. cracks in the garage floor, and
3. cracks in the foundation stem wall of the house proper, the living area.
4. raised foundations with crawl spaces

Let's stick with raised foundations with crawl spaces, particularly ventilation of the crawl space.

Figure 1 shows a crack on the outside of the foundation, at a crawl space vent.

Figure 1. Raised foundation crack at vent

The type of crack in Figure 1 is extremely common and, all other things being equal, is not of a structural concern. On would want to double check the interior of the foundation, as well as the interior floor, wall, and ceiling in that location, to make sure that all other things are equal - 99% of the time, they are.

Any time you put a hole in a hard material, excepting perfectly round holes, the stresses in the surrounding materials will be focused at the corners. That's why round holes and semi-circles are so structurally sound and why you seem them in arches that are thousands of years old and still holding up very well.

Figure 2 shows a crack on the interior of the foundation wall that is a little more problematic.

Figure 2. Concrete block wall

Figure 3 shows a wall that is not only cracked, but excessively deteriorated. Deterioration such as this typically comes from an excessive amount of exposure to water, and since we don't have a lot of rain here in San Diego, the logical culprit are lack of gutters on the roof and a lawn irrigation system that is overwatering the property.

Figure 4 shows interior of the same foundation shown in Figure 3. As you can see, it does not look as bad as the exterior. However, any time you can see the aggregate (rocks) in the concrete, you've got problems that need to be addressed, especially before you go remodeling the interior of the house, and double especially if you plan on putting tile on floors or bathtub/shower walls.

Figure 5 shows a foundation that pretty much doesn't exist anymore. That whole corner of the house was sloping with multiple interior wall and ceiling cracks.

Figure 5. Failed foundation.

The type of water damage shown in Figures 3, 4, and 5 will result in sloping floors, cracked floors, squeaky floors, cracked walls, and cracked ceilings. That I can guarantee you.

There are basically two ways to prevent excessive water damage to a raised foundation:

1. Provide ventilation, very good ventilation. If you walk around a house built on a raised foundation, you'll vents every few feet like that shown in Figure 1. Adequate ventilation allows the interior of the foundation crawl space to air out, so to speak, preventing moisture from becoming trapped in the crawl space.
2. Protect the foundation from moisture. What the homeowner of the property shown in Figure 6 did when he renovated the property was to replace the foundation walls, enveloping them in 52-mm polyethylene to protect them from the soil. Then he laid more polyethylene on the ground and installed a concrete slab on top of it. Next he sealed the foundation vents, plastered and painted the interior of the crawl space, and installed an air removal system (the silver duct, top middle). That provided an interior crawl space that is almost completely sealed and should make the foundation last many, many years longer and probably never look like those in Figures 3-5.

Figure 6. Protected crawl space

Figure 7 shows a homeowner repair of a foundation, and I use the term "repair" very loosely. Generally, a bunch of rip-rap thrown in a hole isn't going to provide any significant support for anything.

Figure 7.

That's it for this lesson. Still to be discussed:

1. foundations with basements
2. retaining walls
3. water and efflorescence
4. foundation planters
5. driveways and walkways
6. solid fences
7. chimneys
8. interior floors
9. interior walls
10. interior ceilings
11. pools and spas

For a previous blog entry on foundations not related to our lessons here, click here.

As always, if you are not comfortable discussing common cracks, hire a professional to help you.

Join us soon for Lesson Six.

Be sure to scroll down for titles and quick links to some of my other blog entries.

Inspired by nature? Join the Inspired By Nature Group.

Classical music lover? Join the Classical Music Group.

Want to share a good book? Join the Active Rain Book Club.

Some of Russel's other blog entries

1. 12 reasons why I won't comment on your blogs
2. How a Seller can cancel the purchase contract during the home inspection
3. What do you do when deceit is obvious? (chapter two)
4. How to help your Clients' house burn down. 
5. That just ain't the way we do it out here, Sonny Boy
6. Not responsible for advice not taken
7. Sometimes it's just a question of semantics and definitions
8. A true real estate nightmare affecting hundreds of people
9. I purposefully burned a bridge yesterday
10. What part of that don't you understand? (Reading 101, English 101, & Spanish 101)
11. If I trip just one more time, I'll have a baker's dozen
12. Out of sight, out of mind, skip the work, charge for it
13. "How much will it cost?" "$399 plus a $100 aggravation surcharge."
14. In a home inspection, if the thing works, the thing works
15. What do you do when deceit is obvious?
16. Sometimes it really is that simple (electric again)
17. Sometimes it really is that simple (attic)