Home Inspection Service for Horry and Surrounding Counties

Getting to the Heart of Structural Flaws:

The ad read, "Handy Man Special, minor structural repairs probable." I had long wanted to tackle a "fixer-upper." I had faith in my basic skills and felt this would be a good way to earn equity in a house. But I was worried. How could I tell if the place was structurally sound?

Well, I bought thae house and fixed it, too. And along the way I found out how to tell if a house is sound.

Here is my recommended "10 minute EKG" for evaluating the foundation of any house you are considering for purchase. You won't become an expert on structural soundness, but it can help you avoid a lemon and know when to seek professional advice.

You'll need a strong flashlight and some basic understanding.

The foundation is the masonry that supports the house. Built into the ground, it supports the weight of the house and keeps the dirt out of your basement. Movement of any part of the masonry usually spells trouble and can be detected by cracks in the walls of the foundaation. You can read some meaning into those cracks.

The foundation usually consists of two parts: the footing and the walls. The footing is a concrete pad about eight inches deep and usually 16 to 24 inches wide. The footing supports the walls, which may be masonry block or poured concrete. The deeper the basement , the thicker the walls must be to resist the pressure of the outside earth. (The concrete slab on the floor of most houses is not a structural component and almost always has some hairline cracks, which are usually caused by shrinkage. These can be safely ignored.) However, never ignore large or multiple cracks in any surface.

To begin your inspection, start in a basement corner and look down the wall sufaces. Make sure the walls are straight (in a flat plane, perpendicular to the floor and ceiling.) Inward bulges in the wall may mean the earth is shoving in and are signs of big trouble. Back off from the wall, walk alongside it, and examine it from top to bottom. Cracks or cracks that have been previously repaired should get close attention. Scan every wall and note what is outside each wall.

It is important to distinguish between the normal cracks found in foundations and those that indicate structural trouble. Don't worry about the house's early settlement (initial movement that usually occurs within the first two years of a house's construction) or very old cracks. Be more concerned with continious movements, not one-time movement.

Diagonal cracks starting in the corners and progressively widening as they rise from the floor are very common. They often step along mortar joints in a roughly diagonal direction and often occur within the first two years of construction. The early movement and resulting hairline cracks usually occur because the footings are unevenly loaded and frequently rest in soils of somewhat differing bearing capacities. (Bearing capacity is the ability to support weight without sinking or compressing.) Small hairline cracks like these are usually safely ignored.

Watch out when you spot the following conditions: A diagonal crack that exhibits signs of recent movement especially if it occurs after initial settlement.

A large crack. (If your finger can fit in it, it is large.)

A long horizontal crack on an outside wall.

A vertical crack on any wall.

A slant or bulge on any wall.

Cracks large enough to admit you little finger are significant and are best examined be someone with experience. Other signs of recent movement are a crack that was filled with mortar and has reopened; or a crack in a recently painted wall with no paint within the crack.

A very common crack is a long horizontal one significant above the slab height. These cracks frequently occur a foot or two below the outside soil surface in a masonry-block foundation and are often caused by water that has collected against the masony, frozen, and then exerted inward pressure.

This usually occurs because the gutters and downspouts have failed to deliver runoff water far enough away from the foundation. Repairing the gutters and spout and increasing the grade (the slope of the soil away from the house) ordinarily will be sufficient to deal with the problem. But if the crack is more than 1'8 inch wide, "pinning" may be necessary. Pinning consists of inserting bars into the cores of the blocks and grouting (filling with concrete) around the bars. This greatly increases the tensile strength of the wall and often isn't very espensive.

Other common horizontal cracks can occur high up on a basement wall on the inside of the foundation wall where it touches the garage slab, that is the concrete that the car rests on in the driveway. When a garage slab (or any outside slab) settles, it can push the foundation wall. But as long as water isn't running down the driveway and getting under the slab there is probably no cause for concern. The force of tree roots can also produce large horizontal cracks and bulges. Remove the root and pin the wall as noted above.

Vertical cracks are usually found at the midpoint of walls; they can be uniform in width, or more commonly, can progressively widen as the crack rises from the floor. This usually means that the corners of that wall of the house are still settling. This is cause for concern.

Hosues that are still settling usually call for "underpinning", a method of enlarging existing footings to better enable them to handle the weight they support. Houses resting over expansive soils may even require piers under their footings to transfer their weight to stable soil. These cures tend to be expensive and call for a professional evaluation.

Almost all structural problems are related to moisture in the soil. If movement is suspected in a house, poor drainage is the likely culprit. So it is particularly important that the drainage around homes be maintained. Houses on hillsides with deep basements sometimes get bulges in the uphill foundation wall. This is often due to poor drainage; the resulting saturated soil increases pressure against the wall. The wall could collapse.

If the gutter downspouts of a house empty at the corners of the house they can frequently saturate the soil, which lessens its bearing capacity. Improving the drainage to eliminate saturation is often sufficient to arrest ongoing movement.