Publication Date: Wednesday, July 20, 2005

Hidden dangers
Cracks and slopes can indicate a need for a stronger foundation

by Erin Pursell

Earthquakes aren't the only things that should make homeowners worry about the strength of their homes.

"People always get especially worried when there's an earthquake," said Tom Anderson, co-owner of Anderson Niswander Construction, Inc., based in Redwood City. "But any time is a good time for thinking about foundation repairs."

Predominant warning signs such as new cracks on walls or ceilings, sloping floors, and sticking windows and doors can come at any time but may become more prevalent during seasonal changes.

"There's a lot of clay in the soil, which expands in seasonal rain, causing houses to rise a quarter to a half inch," said Gene Simpson of Palo Alto-based SimpCo construction.

A 100-year-old foundation in a historic La Honda farm structure crumbles when lightly tapped with a chipping hammer.

"If the foundation is strong, it will either hold the house where it is, or rise and fall with those changes. But if it (the foundation) isn't strong, just one part of the house may rise," Simpson said, adding that this usually leads to further problems.

In general, foundation problems are most common with houses that are about 50 years old, according to Simpson. These problems shouldn't be an issue with homes less than 10 years old, he said. Newer homes with ailing foundations usually indicate a problem with the initial construction of the house.

Some older Bay Area homes are on foundations made with such poor concrete that it can actually be scraped away with your fingers, Anderson said. Mere seismic retrofitting, essentially bolting the home onto its foundation, is not always adequate in many of these cases and more extensive repairs are often needed.

Water pooling under the foundation, another common problem, results from poor drainage around the house and can often cause more serious problems. The best way to avoid this problem is for homeowners to make sure the area around the home is slightly lower than the foundation at the house so water will drain away.

So how do you know water is pooling?

"You get a feeling it's (water) there, and you sometimes check it out and find two or three feet of water," Simpson said.

But this is no laughing matter.

Repairing this kind of damage can cost thousands, he added. That's one reason why people learn to just live with the damage, which is especially problematic during heavy rains.

Simpson recommends a sump pump to help run any excess water leakage out of basement and foundation areas during rainy times.

Water pooling in basements can also indicate foundation problems; cracks in the foundation can allow water to leak in.

Despite all the problems he sees with foundations, Simpson said most work his company does involves repairing damage to wood above the foundation level.

It is rare for him to do foundation work on residential properties, he said, noting the cost. Most of the foundation repairs he does are on commercial buildings, where there is a legal requirement, he said.

In many cases, foundation damage may be a nuisance, but does not make the home a danger as long as it is bolted to the foundation.

The repair process is no easy task. First, the house must be jacked up one to two feet, which alone can typically cost at least $4,000. A complete foundation replacement can take a minimum of two months, Anderson said, and for most homes can cost anywhere from $50,000 to $70,000.

While a cumbersome process, utilities don't have to be turned off and families don't have to vacate during repairs.

Homeowners often take the opportunity to add a basement if they don't already have one, which doesn't add any further complications since the house is already jacked up.

"While a major investment, this will fix the foundation problem, level the floors, and maybe double the size of your house," Anderson said.

When adding a basement, all utilities must be disconnected and the family must move out for up to several weeks -- all things that have to happen before the actual repairs can even begin.

While many homeowners choose to forgo these costly repairs and live with cracks and doors that won't close, it is important to consider a basic level of safety.

At the very least, Anderson said, residents should be certain their homes are secured to the foundation with a seismic retrofit, which usually costs about $4,000 to $7,000, and drainage should be monitored.

"This will go a long way to preserving your investment and keeping you safe," he said. "Remember the 'big-one' (earthquake) is still out there."