New floor and wall cracks concern homeowner

Q. Our house is a 50-year-old Colonial, wood-framed with a brick exterior on the first floor and vinyl siding on the second. I have been getting more cracks lately and am concerned about them. We have 4 or 5 window corner cracks, 2 to 3 feet long, and a ceiling crack all across the width of our master suite.

My garage slab concrete floor has been sinking at the front corners, and the corner adjacent to the front stoop has dropped about 4 inches, while the opposite front has dropped about 2 inches. The sagging is in the floor only as the adjacent pillar sections of the garage are holding up. I am developing a small but lengthy floor crack in the garage as well as the front stoop.

Could the problem be either improper drainage, or chipmunks? My garage gutter's front downspout emptied into a somewhat confined area, now corrected, while the downspouts for the rest of the house have good drainage. I have a large patio in the rear with an unpaved rock garden (about 20 square feet) surrounding my family room fireplace chimney, with nothing to prevent heavy rainfall from soaking in. So far, the brick walls have shown no sign of cracking, but I am beginning to think the rock garden was a big mistake. Of note is our front garden level, which has dropped 6 to 8 inches below the tar markings on the foundation. Our house is built on a foundation, except for the garage and family room, which are on a slab. We also have had a large number of chipmunks in the front and rear yards, with several deep holes dug adjacent to our stoop. Could they be contributing to the problem?

A. It is most unusual that you should get so many new cracks on a 50-year-old house.

Since the first floor brick walls are not affected, it tells me the basic foundation is still sound.

So the problem seems to be with the framed portions of the house, and particularly the second floor. Such movements may be caused by some extensive rotting or insect damage to the framing.

Have you noticed any signs of water leakage over the years? Have you had severe ice dams that may have caused invisible water intrusion inside the walls, wetting the insulation, which cannot dry?

The attic should also be checked to make sure the framing is not suffering from a long-standing moisture problem that may be reflected in the cracks on the master suite ceiling.

Do you have severe termite or carpenter ant problems in your area? Those are wild guesses, but they should be checked out.

As to the garage floor, it is possible that improper drainage may be responsible for its recent settling. Chipmunks can become a nuisance, but it would be unusual for them to cause that much damage. However, if they have dug a number of tunnels into which water can run, it is possible this caused some settling of the soil.

The poor drainage in the rock garden may allow deep water penetration, but since you have not experienced damage to the foundation or brick walls, it does not seem to be something to worry about. If it were a problem, it would result in leakage in your basement or crawl space.

The settlement in the front of the house is likely to be the result of the natural process of rain and time packing the backfill of the foundation, perhaps aggravated by poor final grading and plantings that allowed water to pool and penetrate deeply instead of draining away.

Considering the severity of the problems, I urge you to retain the services of a structural engineer to investigate before more serious damages occur.

Q. Our house has an 6-square-foot concrete platform outside the front door, in a corner under a projection of the garage roof, a foot above ground level, two steps above the front walk, and one step up to inside floor level. The step from the front walk has sunk several inches over the 25 years that we have lived here, probably a consequence of my installation of gutters. The outboard corner of the main platform has also cracked away and sagged a couple of inches.

Several households in the immediate neighborhood have removed concrete front steps and put in new woodish-looking platforms and steps. I'd like to avoid the expense of professional demolition and replacement by putting a new "wooden" platform on the existing concrete, shimmed as necessary, and a similarly shimmed step, hiding the existing concrete. This would be something of a bet that the subsidence has gone about as far as it can go, so I will hedge my bet by providing for releveling later on.

As an amateur handyman with lots of tools, I'd like to do it myself. What do you think?

A. It is more likely that the entire stoop is following the settling of the soil that was used to backfill the foundation.

To build a house, the excavation is several feet wider than the footprint of the house so workers can set forms or build the bock walls, etc.

If the backfill is made with loose natural soil, it will take some time for it to pack enough to become stabilized. Rain, traffic nearby and other natural elements contribute to this. After 25 years, it is very likely that the settling is over.

I see no reason why a talented DIY homeowner should not be successful in building a pressure-treated wood stoop and steps over the concrete structure.

Q. When I read your response to a person who wrote that his ice cubes had a strange taste after he had a new polyethylene water line installed, I think you may have jumped to a conclusion a little too fast without thinking about what the person wrote.

They said they had a new line that was connected to a cold softened line and the cubes had an odd taste whereas when they previously filled trays from the kitchen faucet they never had such an issue.

I have been a licensed plumber for more than 35 years and have never connected certain lines to softened lines. All kitchen cold water, hose bibs and ice makers are always run on a cold water hard line.

It may not always be the case, but the softener probably is the cause of this, not the piping.

A. In my experience, a water softener is installed as close to the service entrance into the house if on city water and just past a pressure tank if the water is from a well.

So all fixtures in the house, except hose bibbs, but particularly kitchen faucets and the hot water tank for its own protection, are supplied with softened water.

The kitchen faucet is the most used in the house and the one where bad taste would be found if it were not on the softened line. My daughter just bought a 15-year-old house in which the kitchen tap water tasted terrible. A water specialist repaired a nonfunctioning water softener and it cured the problem.

The reader experiencing the bad taste in his ice cubes ended his question with the following: "P.S. The taste is that of a chemical nature, as best we can describe, and has subsided considerably since installation."

This is what I based my answer on; the water running through the new polyethylene line had leached whatever gave the water a bad taste.

Replacement of the line with a flexible stainless steel one, which is what should have been used in the first place, is the ultimate answer.

• Henri de Marne, a former remodeling contractor turned columnist and consultant, is the author of "About the House with Henri de Marne" (Upper Access Publishing). He continues to take questions from readers for this column and his website, www.henridemarne.com. Email questions to aboutthehouse@gmavt.net.