6 signs your home could be a lemon (© Image Source/SuperStock; Hemera/agefotostock)

There is no flawless house. Each home, even a new one, has some issues.  The trick is in spotting the really big ones before you sign on the dotted line.

"People get emotionally attached to a house before they understand what the issues are with it," says Kirk Juneau, a home inspector in the Bellingham, Wash., area.

Subtle signs such as tiny insect holes or water behind walls will be next to impossible to detect amidst freshly painted walls, new siding and snazzy appliances. But you can look for several big, flashing cues to some of the worst problems.

When you go shopping for a home, wear old clothes and sturdy shoes. Bring along:

  • A flashlight
  • A carpenter’s level and a child’s marble
  • Binoculars

Here's what to look for:

1.  Foundation cracks
Foundations can crack because they're poorly built or made of insufficient materials, or because the house is poorly engineered. You're most likely to find foundation cracks in older homes. In Seattle, home inspector Darrell Hay says, "New homes have so much (foundation) rebar and structural reinforcing because of building codes that structural cracking is usually unheard of." That's not the case everywhere, though, so check foundations on new homes, as well.

What's your home worth?

Types of foundations include a basement, partial basement and concrete-enclosed crawl space under the house. Not every house has a foundation.  Some homes are built on a concrete slab (called slab on grade) or are set on posts that are sunk into concrete footings (called post and pier).

  • Walk around the outside of the house if you can, looking for cracks in the concrete, stone or brick foundation. (With some homes, shrubbery or a cement board skirting around the foundation make this impossible.)
  • If there's a basement, check the inner walls for evidence of leaks or seeping water, especially where walls meet the floor.

A few hairline vertical or stair-step cracks in concrete are not significant, Juneau says. Likewise, stair-step cracks in a brick or block foundation aren't cause for alarm if they're only in the mortar.

Signs of trouble:

  • A stair-step crack that breaks a brick, block or solid concrete can indicate powerful forces at odds beneath the house.
  • Horizontal cracks, wide cracks (the thickness of your fingernail or greater) or a pattern of cracks starting on one side of a corner and picking up on the other side show the foundation is unable to bear the home’s weight.
  • A crack that is wider at the top is a clue that one part of the house is staying still while another is pulling away, Juneau says.
  • A crack whose surface is uneven can be a sign that the house is shifting. Rub your hand over it to tell if one edge is higher.
  • Be alert with hillside homes where earth movement can cause a foundation to slide. Conscientious builders perform a soil test before they start to learn how solid the earth is beneath the building. A few skip this step. 
  • Pay special attention to homes in a flood plain. Saturation and drying or freezing and thawing can stress the foundation.

The fixes:
There are many possible causes, so costs can vary widely. Fixing a leak may require only a new $50 gutter downspout or $100,000 to lift the house and build a new foundation. A crack might signal weakness throughout the foundation or only in certain spots. Costs also vary with the size and severity of the problem, the size of the home and the materials used. For example:

  • A section of failing foundation might require an underpinning of steel posts sunk into concrete pads. Cost: $20,000 on up. Jacking up the house adds $10,000 or more.
  • Sometimes a slipping foundation can be lifted and moved back into place. Costs begin at several thousands of dollars.
  • If water has penetrated the concrete, turning it soft and powdery, a new foundation — for $10,000 or more — may be required.
  • Repairing a crack from soil instability could entail installing a new drainage system on the lot at a cost of $2,000 or more, or a retaining wall, which can run from $1,000 to $10,000.

2.  A sagging roof
A home's roof sags when it's bearing too much weight, often from too many layers of shingles piled one on top of the other.  "I've had houses that have had a layer of wood shingles on the bottom and two or three layers of asphalt composite shingles on top of that. That will make the roof sag," Juneau says.

Damage from a crushing weight of snow also causes roofs to sag. The damage is compounded when it snows repeatedly. Sagging changes the roof's pitch. Then new snow stays on longer, weighing the roof down more.

Signs of trouble

  • When you drive up, look carefully at the house from the street: Are the chimney and roof line straight? If you can't tell, compare the roof line with the house next door, suggests Jay Balin, owner of Habitat Home Inspection in Thiensville, Wis.
  • Using binoculars, scan the roof's surface. Flat shingles are good. Problem shingles are crinkled or curled. Old shingles may turn up at the ends. Moss will need to be cleaned off or treated.

The fix

  • A sagging roof will need to be replaced. New roofs run $6,000 to $8,000 or more, depending on the roof size, the materials used and whether repairs must be made to the underlying roof supports.
  • You can remove moss from a roof by scraping or applying chemicals that kill it. Cost: Your labor. But do not pressure-wash a roof; you might dislodge the shingles.  Or hire someone to clean off the moss for less than $100.