If a roof or facade was built before 1994, it may contain asbestos, typically in corrugated sheets, small fibre-cement roof slates, old roofing felt or Minerit cladding. Before renovating the roof or facade, an asbestos survey has to establish which materials are present and where the asbestos is. The survey report is what the removal contractor uses to plan the work and put together a quote.
What kinds of roofs contain asbestos?
An asbestos roof is not one particular type of roof. Asbestos was used in several roofing materials, and a single roof may have several different materials layered on top of each other.
Corrugated Eternit and Minerit
A grey corrugated sheet roof is a familiar sight on detached houses, saunas, garages, farm buildings and industrial halls. Corrugated Eternit and Minerit roofs used asbestos cement for decades. An old sheet is often covered in moss, with a rough surface and chipped edges. Asbestos-free corrugated fibre-cement sheets made later look the same, so the age of the roof is the most important clue. Corrugated sheets are also common on smaller buildings around the property, such as carports and sheds, which are easily forgotten in the renovation plan.
Fibre-cement slates
A roof made of small fibre-cement slates looks similar to a natural slate roof and was especially common in the 1970s and 1980s. An old roof of this kind may contain asbestos, as may other slate-style fibre-cement roofing. The small size of the slates does not reduce the risk: every slate that is cut or broken is handled during removal in the same way as a large sheet.
Bitumen roofing and roofing felt
On flat roofs, terraces and balconies, old layers of felt are often stacked on top of each other. The bottom layers may contain asbestos even if the top layer is new. This is covered in more detail in asbestos in roofing felt. Where needed, the survey also examines sealing compounds around roof penetrations, chimneys and eaves.
Minerit sheets as exterior cladding
Minerit sheets were used as exterior cladding in both flat and profiled form. Typical locations are the facades of detached and terraced houses, plinth boards, eaves, balcony panels and the cladding between windows in apartment buildings. A facade renovation, extra insulation or window replacement means the sheets have to be removed, cut or drilled, so their composition must be established before work starts. Painting changes nothing: a painted sheet has the same composition as before it was painted. The differences between board types are covered in asbestos sheets: Luja board, fibre cement or Minerit.
More on facade boards: asbestos in facade panels.
What if a new roof has already been laid over the old one?
On corrugated sheet and felt roofs in particular, the new roof has sometimes been laid over the old one. The old material is then hidden, but it has not gone away: the next time the roof is replaced or the building is demolished, the lower layers come off too. The same applies to facades where timber or metal cladding has been fitted over the old Minerit cladding. Where needed, the surveyor can open up the structure so that hidden layers are examined as well. When ordering the survey, mention any earlier repairs to the roof or facade that you know of.
Why does asbestos roof removal start with a survey?
The Finnish Asbestos Act (684/2015) and Government Decree 798/2015 on the safety of asbestos work require an asbestos survey before renovation and demolition work in buildings built before 1994 or containing materials from before 1994. Roof and facade renovations almost always fall within this, because old roofing or cladding is removed. The survey is also useful in practice:
- It shows which materials must be removed as asbestos removal work and which can be removed as ordinary demolition.
- Contractors can give comparable quotes based on the same information.
- The renovation does not grind to a halt because asbestos turns up halfway through the removal.
- The garden, the neighbours and the inside of the building can be protected properly.
- The workers know in advance what protective equipment and working methods each part of the building requires.
What does the survey report tell the removal contractor?
The asbestos survey report is the removal contractor's most important source of information. For a roof and facade project, it typically shows:
- the basic details of the property and the parts of the building examined, such as the roof, facade, eaves and plinth
- where each sample was taken and a description of the material
- the laboratory result for each sample, analysed with a JEOL SEM-EDS electron microscope
- a summary of which materials asbestos was found in and which it was not
- recommendations for next steps
Asbestos roof removal is priced per project. The price depends on factors such as the roof area, pitch and height, the need for scaffolding and how easy the site is to access. Removal contractors base their quotes on the survey report. For more on what affects the price, see asbestos removal price.
The practical order of work for a roof or facade renovation
- Find out the construction year and earlier renovations. If the roof or facade was built before 1994, or you do not know when, the materials need to be tested.
- Order an asbestos survey before asking for quotes. Depending on the city, a survey costs from 119 € incl. VAT, and the price covers the survey, all samples, the analysis, travel and the report. For demolition projects, 100 € is added. We carry out on-site surveys in Southern Finland; elsewhere you can post samples for 39,90 € + VAT per sample.
- Ask for removal quotes with the report attached. When every contractor receives the same report, the quotes are easy to compare.
- Removal. The asbestos-containing parts are removed by a company authorised to carry out asbestos removal work, which also handles the asbestos waste. AsbestiPro carries out surveys and analyses, not removal work.
- New roof or cladding. Once the old materials have been removed, the renovation continues as normal. Keep the survey report with the property documents, as it will be useful for later repairs and if the property is sold.
What should you not do to an old asbestos roof?
An intact asbestos cement roof does not usually release significant amounts of fibres, but working on it changes that. An old sheet roof should not be pressure-washed, scrubbed with a wire brush, sanded, drilled or cut with an angle grinder, because this releases fibres and spreads them around the property. Find out what the roof is made of before cleaning, coating or repairing it. When you are ready to start, order an asbestos survey before asking for removal quotes.