Tilting floors, asbestos roof call for close attention

Inspector's Eye

January 27, 2002|By Dean Uhler

Amy and Dan Rossi of Crownsville are considering buying an Eastern Shore house built in the 1920s, with an "asphalt/asbestos roof" that needs to be replaced. They asked about the difficulty and expense of removing the old roof. Also, the floors slope toward the center of the house and they are wondering whether this is necessarily a bad thing.

Starting with the second part of the question, floors that slope toward the center of an old house are obviously undesirable for practical reasons, but whether they pose a structural problem depends on considerations such as how far out of square the rooms are, the cause, what effect it has had on structural connections, and whether movement is still occurring and, if so, how fast.

A number of factors can contribute to the sag in the middle.

Some fall under the catch-all phrase "normal settlement," including moderate deflection of beams and joists under load, shrinkage of wood columns and bearing walls as lumber dries out after construction, and closing of gaps at joints in the framing as the weight of the house compresses them.

On the other hand, settlement can occur because of factors such as subsidence of footings under columns or bearing walls supporting the house, rot or insect damage to wood framing and split beams.

A house in Baltimore comes to mind that was so crooked that people were speculating as to whether someone living in the house would choose to sleep feet uphill or downhill - putting a bed sideways to the slope didn't seem like an option if you didn't want to roll off the bed.

In that house, the footing under a bearing wall appeared to have gradually subsided over about 80 years to reach its advanced state. The house did not appear to be imminently unstable, but there was every indication that, without repair, the settlement would slowly continue, possibly reaching a state where torqued connections in framing and bearing walls would become a problem.

A more common problem in old houses is wood columns in the basement that have rotted at the bottom because of chronic moisture. Often, the rot has caused subsidence as the weakened wood is crushed under the house's weight.

For an opinion on the unevenness in the crooked house you want to buy, have the structure looked at by a home inspector or engineer with knowledge of old houses.

Regarding replacement of the asphalt roofing shingles, the first step is to confirm that they contain asbestos.

Although asbestos apparently was an ingredient in some three-tab asphalt shingles in the past, I am unable to determine how common it was. The White Lung Association, based in Baltimore, states in its Web site that asbestos was used in asphalt shingles from 1971 to 1974, a figure used in several other sources I found. The only way to be certain is to have a sample tested by a laboratory, which should cost less than $75.

If the shingles contain asbestos, precautions should be taken. Asbestos roofing shingles are considered nonfriable, and removal is allowed without special procedures provided they are not severely damaged in the process.

Asbestos-containing asphalt shingles can be removed by prying the shingles loose and lowering them to the ground. To suppress fugitive fibers, the shingles should be wet during the project.

If the roof is so steeply pitched that wetting it makes it too dangerous to work on, extra precautions should be taken to remove the material with as little breakage as possible. After the material is lowered to the ground, it should be misted and wrapped in plastic.

Inspector's Eye

Dean Uhler has been a home inspector for more than 12 years and is president of Baltimore-based Boswell Building Surveys Inc. Uhler is a member of the American Society of Home Inspectors (ASHI) and is the treasurer of the Greater Baltimore Chapter of ASHI.

Questions, with name, address and daytime telephone number, about homes and home inspections can be faxed to 410-783-2517, e-mailed to real.estate@baltsun.com or mailed to Inspector's Eye, Second Floor, 501 N. Calvert St., Baltimore, Md. 21278-0001.

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