Hazards when you renovate an older home - Pro Construction Guide
Beware these hazards when renovating older homes and buildings

Beware these hazards when you renovate an older home

Old shingles can contain lead

Old shingles can contain lead, and though less likely to become friable they still should be handled appropriately.

If you renovate older homes and buildings, you can face some serious safety risks due to the presence of hazardous materials, fumes from toxic chemicals, dust, and live electrical or gas utilities, as well as the potential for structural failures. Beware these hazards when you renovate an older home.

Asbestos and lead paint are the most commonly found hazardous materials in older buildings. Both were widely used prior to being prohibited in the 1970’s and 80’s due to the inherent health risks.

Asbestos hazards

In the renovation of older homes and buildings, asbestos containing materials (ACM) are prevalent and dangerous. ACMs were used in insulation, flooring, adhesives, sprayed on fire proofing, ceiling tiles, floor tiles, putties, caulk, joint compound, wall and ceiling texture materials, siding and roof shingles.


When removing VCT (vinyl composition tile) formerly called VAT (vinyl asbestos tile) be skeptical of tiles that are smaller than 12 inches x 12 inches. Older VAT tiles were often a smaller size, such as 9 inches x 9 inches. The adhesive below VCT and VAT can also contain asbestos. In some cases, old floor tiles can legally be tiled or carpeted over, without abatement. If penetrations or disturbances to the floor are required, proper removal is required.

Each one can be hazardous to varying degrees, and the methods used to test for, abate and encapsulate them are strictly controlled by OSHA.

When asbestos is disturbed, it can become airborne, or “friable,” which is by far the greatest hazard. If these miniscule asbestos particles are ingested or inhaled, they can cause serious illnesses, including mesothelioma and various types of cancer, although the symptoms may not surface for many years.

Roof and wall insulation and pipe coverings are probably the worst sources. Over many years, they become dry and easy to crumble. Shingles, floor tile and adhesives are less likely to become friable but still need to be handled appropriately.

It’s typically the owner’s responsibility to ensure no ACM materials are present in the building. Contractors are typically required by the terms of the contract to stop work immediately and notify the owner if they encounter any materials suspected of being asbestos.

Should ACM be located, or even just suspected, the owner is required to employ professional firms to sample and test the material in question. If ACM is verified, special containment, removal and air testing procedures must be conducted, until the material has been totally abated or encapsulated, and air samples prove that no risk remains.


In some cases, asbestos containing materials can be legally disposed of with the demolition debris itself without the need for abatement. How and where this debris is disposed of must be properly performed and documented. As an example, asbestos shingles on a dormer would not need to be abated prior to demolishing and disposing of the framing, sheeting, etc. of the dormer itself. Always check local codes to see if this disposal option is allowed.

Prior to 1978, lead was used as a pigment and drying agent.

Prior to 1978, lead was used as
a pigment and drying agent in
oil-based paints.

Lead paint hazards

Prior to 1978, lead was used as a pigment and drying agent in oil-based paints. That lead-containing paint can cause a health risk if ingested. Federal law requires contractors performing renovation, repair and painting projects on homes built before 1978 (also child care facilities and schools) be certified and trained to prevent lead contamination.

The regulation applies if the work is being done for compensation and a painted surface is being disturbed that exceeds 6 square feet in an interior or 20 square feet of exterior; painted walls are being demolished, sanded or scraped; and/or windows are being removed and replaced.

If the work does not meet these conditions, however, the Environmental Protection Agency (EPA) allows contractors to dispose of lead-based paint waste as household waste disposed of as municipal waste, and managed according to state and local requirements. Residents are also allowed to discard lead-based paint waste in this way.

EPA encourages anyone who handles lead-based paint to collect paint chips, dust, dirt, and debris in plastic trash bags for disposal. A covered dumpster is preferred for storing the debris until the job is done. Always contact local authorities to determine where and how lead-based paint debris can be disposed of.

Utilities hazards

Live building utilities, such as natural gas and electricity, cause obvious risks. The power stays ‘on’ during most renovation projects, so temporary lighting and power tools can be used, without the need for portable generators. During demolition, it’s critical that power is de-energized.

Many times it’s difficult to be 100 percent certain of how various devices are circuited, especially in older homes where homeowners or less-skilled contractors may have installed new work without regard to code compliance. When in doubt, be sure to test any device to make sure the power is off, prior to starting any demolition activities.

When any electrical work is being performed on a live system, the ‘lock-out tag-out’ procedure is vital to ensure a panel is not inadvertently energized while workers are exposed to circuits or device that they think are off.

Natural gas piping presents an obvious fire risk. While not necessarily a health risk, a broken water pipe can result in serious damage and costs. Gas piping is easy to locate and shut off during construction, but water pipes are often not visible. Before any demolition starts, make sure both utilities are turned off and isolated from work areas.

Other hazards when you renovate

Other hazards when you renovate an older home include abandoned paint cans and other improperly stored chemicals, which should be removed to avoid the risk of fire or health risks due to fumes.

Also, chemicals, such as cleaners, bleaches, acids, solvents, etc. can present a health risk if they are inhaled, ingested, absorbed through contact with skin, or injected by accidental puncture.

Ventilation is a key consideration during all construction activities for any type of building. Strong fumes are common due to paints, adhesives, welding, gas-powered equipment and temporary heaters and should be thoroughly disbursed with fresh air to mitigate the potential health risks.

Even construction dust from relatively mundane materials, such as sawdust and coal, can explode if the right concentrations exist and come in contact with a spark or open flame.

–By Bruce Webb, general contractor

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