Cracks happen for all sorts of reasons. Different construction materials have different expansion and contraction coefficients, some materials change shape and size as they absorb water and water vapor while materials immediately adjacent to them do not budge, and Mother Earth is a dynamic body - meaning soils can move!

Understanding House Settling Cracks

If you have an understanding as to why cracks happen, then you can often work to make permanent repairs. There are some cracks that can't be easily repaired. What's more, it is hard to totally disguise some cracks. Large houses have joints within them. These are places where the house relieves movement, just like the joints in our fingers, arms and legs. I often see cracks in modern homes where columns support beams. You can see cracks right where the contact point between these two structural members meet.

Hardwood floors often develop cracks. There are all sorts of reasons for that to happen, and almost always they can be traced to a humidity or moisture problem.

Soil Problems

I routinely act as an expert witness in court cases involving poor quality construction. Recently, I finished a case that involved a house built on poor soil. The foundation actually dropped several inches in numerous places and caused all sorts of havoc within the home and in its outside walls. There were huge vertical cracks in the brick work, the basement floor looked like an earthquake had struck and interior steel I-beams were twisted and compressed so much that they were crushing 2x4 plates. I was amazed at what can really happen when houses are built on poor soil.

If you are getting ready to build a home, you need to realize that certain subdivisions are cut and fill operations. In other words, the developer takes dirt from one place and uses it for fill in other parts of the subdivision. If this soil is not placed with great care, it can settle! If you think that you are building on fill dirt, by all means spend the extra money to get it tested by a soil engineering firm. If you don't and you end up with problems, I GUARANTEE you that you will spend ten times the amount hiring an attorney! Request soil inspections in your contract and hire the soil testing company yourself.

Shallow Foundations

Many houses are built on slabs or have crawlspaces. The footers for these structures need to be placed just below the frost limit in the local area. The closer the frost line is to the surface (warmer climates) the greater chance you might have for droughts that cause your foundation to move.

If you live in an area of clay soils and have seen a dried mud puddle with large cracks in it, then you have expansive clay soils in your area. Not only do these soils shrink sideways as they dry (this creates the cracks you see), but they also shrink down in volume. The shrinkage can be dramatic and can cause all sorts of cracking, door and window fit problems, etc.

You can plan ahead and minimize foundation movement if you install water injection pipes next to the footer when you build the structure. I always did this on my jobs and it has given my clients the ability of tricking the soil under their houses and room additions into thinking it is raining up there on the surface!

The way you trick the soil is to install a four inch perforated pipe along the side or on top of the footer of the shallow foundation. You install one or two tee fittings in the piping so that you can extend a vertical riser pipe up to the surface. Install a loose fitting cap over this riser. When the drought hits, you simply let a garden hose run very slowly in the riser pipe for 24 hours or so. The pipe will evenly distribute the water around the footer if you have installed the footer fairly level. This system is simple and inexpensive to install and will save you hundreds of dollars in repairs and lots of headaches as well!

If you are getting ready to build in an area that has expansive clay soils, HIRE a soils engineer and a structural engineer to tell you how to design the foundation to withstand the differential soil movements that will occur!

If you try to fix a house that has cracks, talk with a structural engineer. If you pier one or more corners, you may create new stress points at other places!