Now while “stretch marks” may not be a topic anyone wants to talk about or SEE, this is about a different kind of stretch marks and how we can actually learn something useful from them.
You may be thinking this is a bit of a “stretch,” but I am serious. I did in fact use stretch marks to diagnose settlement—-and not any of the kinds of settlement you might be thinking of.
In this case the front porch on the house was settling. It is a condition that is quite common with older homes—and even improperly constructed newer homes. Entryway structures are often installed over inadequately compacted ground, and over time they settle.
The question I usually get is, “Is it going to get worse?” Often times there are already many different vintages of patches where people have tried to keep a crevasse from developing between the structure and the house. It can get so bad that the whole structure has to be rebuilt.
As you can see in this picture the Stretch Marks in this heavy coating applied over the wood deck structure graphically shows how there has been some settlement of the supports under this deck since the paint was installed. So in this case the settlement is ongoing and will have to be taken into account when repairs are made.
Believe it or not, the gap at the left of the brick was not always there. Over the years the brick support structure has settled and pulled away from the house. In this case the entire walking surface on top of the brick structure had been rebuilt to compensate for the crevasse that would otherwise exist at the doorway.
The stretch marks tell us that this settlement is continuing and a new crevasse will be forming.
****
Charles Buell, Seattle Home Inspector
If you enjoyed this post, and would like to get notices of new posts to my blog, please subscribe via email in the little box to the right. I promise NO spamming of your email
Oh, foundations! My favorite subject of worry. When we had the house inspected before purchase, about a dozen years ago, the inspector referred to cracks in the foundation of this one-story ranch house which are across from each other on opposite sides of the house. This, he said, makes the house move up and down as if on a hinge. On further questioning he said it was not beyond normal. This is in Oregon, lots of clay in the soil, lots of swelling and shrinking, and things do move around. And then there are a couple of large trees not quite 15 feet from the house and I would guess their roots have some effect.
When we moved in, I marked the crack’s open dimensions on the sill of the outside entry to the crawl space. Over a decade, it did not change. After that marks were erased just by abrasion when work was done in the crawl space. The house does move up and down a bit, but so do the houses of some friends whose foundations don’t have such cracks. In one friend’s older house, the sliding shower door doesn’t fit at some times of year. In my house we discovered later that the strike plate in several doorways had space cut for adjustment up and down, and it has been necessary to use this. Diagonal cracks appear above some interior door frames and reappear a couple of years after patching.
The floors of the house slope a bit, one way or another, noticeable to the eye only if you look carefully. All the support posts underneath the house have been checked, and repaired where necessary — only one needed repair; a new cement block was poured beneath it. All the posts were adjusted as necessary for the most level possible floor a few years ago, mostly a matter of shimming. The house is on a pad on a moderately sloping site, and when aluminum extrusion gutters were installed across the length of the roof a few years ago, the installers told me the whole house slopes in the same direction as the slope of the hill.
This is a long post to ask, do you think I’m justified in thinking the house has finished settling? With the soil here, houses will move around unless they are built better than was standard when this one was built, more than 35 years ago, as a spec house. So settling is relative, I think. Of course, you can’t really say without seeing it, but maybe you can make a comment based on your experience with these issues in the Pacific Northwest. Some of the bad support posts you’ve shown in pictures of crawl spaces have already made me feel much better about the ones this house has.
Elana, the real answer to your question might be just as long 🙂 But really, in this area, we typically can pretty safely say that a 35 year old house will be pretty much done settling. But there are so many factors that can change that assessment—like roof water drains terminating at the foundation because the drains are now clogged, or earthquakes etc. Of course we are not for the most part troubled with expansive soils like other areas of the country—although there are pockets where that occurs here as well. If you are in an area of expansive soils the house will likely continue to rock and roll as it has in the past but if it has never gotten out of control it may not get any worse—of course changes in ground water levels can alter that condition as well. A soils engineer can best assess your particular situation and if stabilization is warranted can design a system to make the foundation perform better.
Given the aged look and the steep front slope of the grade, I’d say the underlying cause here appears to be more of a soil erosion/ movement problem. Permanent repairs will require a new stoop or just keep patching because it’s not a critical part of the structure and it’s not going to fall off. But I would be concerned about how any surface or subterranean ground erosion may eventually affect the main foundation.
Bye the way, I see this shear stretches in the interior gypsum tape joints as well and use them to diagnose.
Daniel, yes those tape mark stretches are a good barometer too.