Asbestos in a renovation: how to check before demolition

If the building you are renovating, or its surfaces, date from before 1994, asbestos must be checked before demolition, sanding or chiselling. A single suspect material, such as tile adhesive, filler or the adhesive under a vinyl floor, can be tested by taking a sample and sending it to a laboratory. Larger demolition or repair work usually requires an asbestos survey, carried out on site by a qualified surveyor.

Finding asbestos in a renovation is not unusual. It was used in many ordinary building materials and cannot be identified by eye. This article explains how to find out whether a property contains asbestos, when a sample is enough and what to do if asbestos turns up in the middle of the work.

Why must asbestos be checked before a renovation?

An intact asbestos-containing material does not release fibres. The risk arises when the material is broken: sanded, drilled, chiselled or torn off. Fibres can then be released into the air, and breathing them in can in the long term cause serious diseases such as asbestosis and mesothelioma.

The check is also a legal requirement. The Government Decree on the safety of asbestos work (798/2015) requires the asbestos content of materials to be demolished to be investigated before demolition work begins, when the building was built or repaired before 1994. Responsibility for the investigation lies with the developer, which in a home renovation is often the renovator.

The practical reason is just as important: if asbestos is found only during demolition, the work stops, the schedule slips and costs rise. Checking in advance is almost always the cheaper option.

How do I know whether the property I am renovating contains asbestos?

Only a laboratory analysis gives certainty. You can still start the assessment with three questions:

• When was the building built or last renovated? If surfaces or structures date from before 1994, asbestos is possible.
• Which materials are you going to demolish or break? Typical ones are tile adhesives and mortars, wall and ceiling fillers, vinyl flooring and its adhesives, vinyl tiles, pipe insulation and various boards.
• Has the property already been investigated? The housing company or the previous owner may have an earlier survey or sample results. Check that they cover exactly the materials the renovation will affect.

The most common renovation areas are bathrooms, kitchens and floors. In a bathroom, asbestos can be in the adhesives and fillers behind the tiles; in a kitchen, in wall fillers and in the adhesive behind splashback tiles; and in floors, in the adhesives under vinyl flooring and vinyl tiles. Read more in the articles asbestos in the bathroom and asbestos in tile adhesive.

Is an asbestos survey needed, or is a sample enough?

It depends on the scope of the renovation and on what information the planning of the demolition work requires.

• A sample is often enough when you want to know whether a single, well-defined material contains asbestos. Examples are the tile adhesive in one room or an old vinyl floor. You can take the sample yourself following the instructions and send it to the laboratory.
• An asbestos survey is needed when there are many materials to be removed, the renovation is extensive, or the property needs a written survey report for planning the demolition work, as is often the case in housing company projects. In a survey, a qualified surveyor goes through the property, takes the necessary samples and writes a report.

Onelab is a laboratory: we analyse samples but do not carry out on-site surveys. Surveys are handled by our sister brand AsbestiPro. The difference is explained in more detail in the article asbestos survey or asbestos analysis. If you are unsure which suits your situation, you can ask us before sending samples.

How do I take an asbestos sample at the renovation site?

You can take the sample yourself when the material is intact and the sampling spot is small. The key is to take the sample from exactly the material you plan to remove, and so that every layer is included. In a bathroom wall, for example, that means the tile, the adhesive and the filler all the way down to the substrate.

• Wear disposable gloves and preferably a respirator of at least class FFP3.
• Lightly mist the sampling spot so that as little dust as possible is produced.
• Using a knife or chisel, remove a piece of about 2–5 centimetres and put it straight into a zip-lock bag.
• Put the bag inside a second bag and mark it with the room, spot and material.
• Cover the sampling spot with tape and wipe the area with a damp cloth.

Take one sample of each different material. If the bathroom floor and wall have different tiles and adhesives, they are two separate samples. More detailed instructions are in the article how to take an asbestos sample.

What should I do if asbestos is found in the middle of a renovation?

Stop work at that spot immediately. Do not continue sanding, drilling or demolishing, and do not clean up the dust with an ordinary vacuum cleaner or brush.

1. Cordon off the work area and keep others out of the room.
2. Take a photo and record the exact location and material.
3. Take a controlled sample of the suspect material, or call in a professional if the material is extensively damaged.
4. Wait for the laboratory result before deciding how to continue.
5. If the result is positive, the removal is planned as asbestos work and carried out by a company authorised for asbestos removal work.

If the result is negative, you can continue working on that material. Remember, however, that the result only applies to the material tested: if a new layer or a different material is revealed during demolition, it is tested separately too.

A calm pause is almost always cheaper than guessing. A more detailed sequence of steps is in the post suspected asbestos in the middle of a renovation.

Checklist before the renovation starts

Go through these points before the first tile comes off or any filler is sanded:

• Find out the age of the building and its surfaces.
• List the materials that will be demolished, sanded or drilled.
• Ask the housing company or previous owner for earlier surveys and sample results.
• Decide whether a single sample is enough or a survey is needed.
• Take the samples following the sampling instructions so that every layer is included.
• Label each sample: room, spot and material.
• Allow time in the schedule for the results before demolition begins.
• Share the results with the contractor and everyone else involved before work starts.
• If asbestos is found, request a quote from a company authorised for asbestos removal work before the contract is fixed.

How much does an asbestos sample analysis cost?

At Onelab the analysis costs €39.90 + VAT per sample, and the price is the same for 1–100 samples. Orders of more than 100 samples can be priced separately. Postage is not included. Samples are analysed with a JEOL SEM-EDS electron microscope, and the result is sent by email, typically on the day the sample arrives. If you send the samples well before demolition and allow for postal delivery time, you will have the result before work begins. See the price list or order the analysis online.