Asbestos in concrete is one of the most common findings when properties built from the 1950s to the 1980s start to be renovated in Finland. Asbestos fibers were mixed with cement, mortars and pre-cast concrete elements to improve the strength, fire resistance and weather resistance of the materials. The use of asbestos in building materials was completely banned in Finland only before 1994, so concrete structures can still contain significant amounts of asbestos.
Why was asbestos added to concrete and mortars
The properties of asbestos made it an ideal additive for the construction industry. The fibers could withstand high temperatures, strengthen the cement mass and improve moisture resistance. Both on-site cast structures and industrially produced sheets and profiles were made from asbestos cement. Asbestos plaster, on the other hand, was widely used in masonry mortars and plastering of facades, because it adhered better to the substrate and was resistant to cracking.
Typical sites where asbestos in concrete occurs
Asbestos-containing concrete and asbestos cement were used in many parts of the building. The most common items are:
- Concrete elements of exterior walls and asbestos-cement sheets for facades
- Plinths and foundations, which used asbestos-containing mortar
- Balcony railings, tiles and concrete structures
- Yard stones, sewer pipes and well rings
- Pipe casings and chimneys, where asbestos cement served as fire protection
- Leveling of intermediate floors and roofs
Especially in 1960 and 1970 apartment buildings asbestos in concrete is almost the rule, not the exception. Asbestos is also often found in the plaster of foundations and chimneys of single-family houses.
Years of construction and prevalence of asbestos
The greatest risk for the presence of asbestos is in buildings that were built or renovated between 1950 and 1980. The use continued partly until the end of the 1980s, and the stored products were still used before 1994. If the property was built during this period, the risk of asbestos in concrete structures cannot be ruled out without sampling and laboratory analysis.
Can asbestos be identified visually?
Visual identification is not reliable. Asbestos fibers are microscopically small and mix evenly in the cement mass. Outwardly, old concrete or mortar can completely resemble ordinary building material. The only reliable way to confirm the presence of asbestos is to take a sample of the material and analyze it in an asbestos laboratory.
Renovation risks when asbestos is treated in concrete
Solid asbestos cement in itself is not an acute health risk when it is intact in place. Danger always arises when the material is worked on. Drilling, sawing, grinding, pickling or removal work release microscopic asbestos fibers into the air, which when inhaled cause serious lung diseases decades later.
Finnish legislation requires an asbestos survey before all demolition and repair work involving structures built before 1994. This also applies to small measures, such as drilling holes in a concrete wall or renewing tiling.
What to do if you suspect asbestos in concrete structures
If you are renovating a property built from the 1950s to the 1980s, order an asbestos survey before starting the work. A professional takes representative samples of all suspicious structures and laboratory analysis confirms the content. Based on the survey report, you know exactly which structures must be treated as asbestos demolition and which are safe. This way you avoid both health risks and subsequent problems with the authorities. Order an asbestos survey on time, and your renovation will proceed smoothly and safely.