Asbestos in parquet adhesive: sanding, removal and sampling

The adhesive under old parquet can contain asbestos, but the wooden parquet itself does not. The risk concerns parquet that was glued directly to concrete or levelling compound before 1994, such as the mosaic parquet found in many older apartment buildings. The adhesive is often a dark, bitumen-based compound, but its colour does not tell you whether it contains asbestos. You get certainty by taking a sample of the adhesive under the parquet and of the levelling compound beneath it, and having it analysed in a laboratory.

This article explains which types of parquet were glued to the subfloor, which parquet jobs actually reach the adhesive, how to get at the adhesive and sample it, and what the result means for your floor renovation. Adhesives under vinyl flooring, and the question of adhesive colour, are covered separately in the article asbestos in adhesive.

Which types of parquet were glued to the subfloor?

The asbestos concern is the adhesive layer, so the first question is whether the parquet was glued to the subfloor at all. The installation method tells you where the adhesive is and whether there is any.

Mosaic parquet

Mosaic parquet made of small wooden pieces was typically glued straight onto the concrete slab or levelling compound, and it is common in older apartment buildings. The adhesive covers the whole floor, and much of it stays on the concrete when the parquet is removed.

Glued strip and plank parquet

Larger parquet strips and planks were also glued down over their full surface. In that case the situation is the same as with mosaic parquet: the adhesive is under the entire floor.

Nailed and floating parquet

Parquet nailed to battens and floating parquet laid on an underlay are not attached to the subfloor with adhesive, so there is usually no parquet adhesive under them. A floating floor can, however, hide an older floor, such as vinyl flooring with its adhesive or adhesive residue from an earlier parquet. These are separate materials and are tested separately. Vinyl flooring is covered on the page asbestos in vinyl flooring.

Levelling compound under the adhesive

Under parquet adhesive there is often a floor levelling compound, which is a layer of its own and can also contain asbestos. More on this on the page asbestos in filler and levelling compound.

Does sanding parquet reach the adhesive?

Not every parquet job touches the adhesive. It is worth thinking first about what is going to be done to the floor.

• Sanding and surface finishing: ordinary sanding followed by lacquering or oiling works on the surface of the wood. It usually does not reach the adhesive, as long as the parquet still has enough wear layer left and the sanding does not go through the wood.
• Replacing individual pieces: lifting a loose or damaged piece and gluing in a new one breaks the old adhesive over a small area.
• Removing the parquet: taking up the parquet breaks the adhesive layer across the whole floor.
• Removing adhesive residue: scraping, sanding or grinding adhesive left on the concrete is usually the dustiest stage of a floor renovation.

If the parquet is worn so thin that sanding might go through the wood, or if pieces have come loose and adhesive is visible underneath, it is worth testing the adhesive before you sand.

Why is parquet adhesive tested separately?

Parquet adhesive is a different product from vinyl flooring adhesive, even though both can be dark and bitumen-based. The same flat may have parquet in the living room and vinyl in the kitchen, and their adhesives and levelling compounds come from different periods and manufacturers. The result from one floor therefore tells you nothing about another. A good rule of thumb is one sample per different floor build-up. The number of samples is covered in more detail in the article how many asbestos samples are needed.

Asbestos was used above all in bitumen-based adhesives, which were used to glue parquet, vinyl sheet flooring and vinyl tiles, among other things. Old bitumen-based adhesives can also contain PAH compounds in addition to asbestos. PAHs are a different matter from asbestos and are not part of an asbestos analysis, so they are worth bearing in mind when the removal work is planned.

In an apartment building, removing parquet is usually an alteration that must be notified to the housing company before work begins, and the housing company may require the materials being removed to be tested for asbestos. More on this in the article asbestos in apartment buildings.

Where can you get at the parquet adhesive?

The adhesive is under the parquet, so for the sample you need to lift one piece or find a spot where the adhesive is already visible. Good places are:

• a piece that is already loose or creaks
• at a threshold or doorway, where the edge of the parquet is exposed
• under the skirting board next to the wall, if the skirting is coming off anyway
• under a cupboard or built-in furniture, where the mark will not show
• around a pipe penetration or radiator, where the parquet has often been cut and patched

If the floor has been repaired, a patched area may have a different adhesive from the rest. Take the sample from the area you plan to remove.

How to take a sample of parquet adhesive

1. Wear disposable gloves and a respirator of at least class FFP3.
2. Lightly mist the sampling spot with a spray bottle to keep dust to a minimum.
3. Lever up one piece of parquet with a chisel so that adhesive stays on its underside. Do not sand or drill to expose the adhesive.
4. If the piece is small, you can send it with the adhesive attached. From a larger strip, a piece of about 2–5 centimetres with adhesive on the underside is enough.
5. With the chisel, also scrape up adhesive left on the subfloor and a small piece of the levelling compound beneath it.
6. If there is an older floor layer under the parquet, such as vinyl flooring, include a piece of it too.
7. Drop everything straight into the same zip-lock bag, seal it and put it inside a second bag.
8. Mark the bag with the location and the layers, for example "living room, mosaic parquet + black adhesive + levelling compound".
9. Cover the sampling spot with tape and wipe the area with a damp cloth.

When all the layers are in the same bag, the result applies to the whole floor build-up. If you want to know whether the asbestos is in the adhesive or in the levelling compound, send them as separate samples. General instructions on tools and packing are in the article how to take an asbestos sample.

What does the result for parquet adhesive mean?

Onelab analyses the sample with a JEOL SEM-EDS electron microscope in accordance with ISO 22262-1, and the result is sent by email, typically on the day the sample arrives. The result tells you whether asbestos was detected in the sample you sent.

• No asbestos detected: the result applies to the floor build-up at the sampling spot and to similar floors. Rooms with a different parquet, a different installation method or repaired areas are tested separately.
• Asbestos detected: the parquet adhesive layer is treated as asbestos-containing. Removing the parquet and the adhesive residue is planned as asbestos work, and the removal is carried out by a company authorised for asbestos removal work. If the parquet is intact and only lightly sanded, or a new floor is laid on top of the old one, the adhesive may not need to be disturbed at all.

If the floor is part of a larger renovation or demolition that requires an on-site asbestos survey, the survey is carried out on site by a qualified surveyor. Onelab is a laboratory, and on-site surveys are handled by our sister brand AsbestiPro.

How much does a parquet adhesive analysis cost?

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. You can order the analysis online and send the sample to the laboratory by post.