What are wood preservatives?
Wood preservatives are chemical preparations intended to protect timber against fungi, insects and weathering. The concept sounds sensible — the problem lies in the active ingredients: many wood preservatives used extensively in Austria until the 1980s and 1990s contain highly toxic and persistent chemicals.
The main pollutants in old wood preservatives:
- PCP (pentachlorophenol): Fungicide and insecticide. Carcinogenic, hepatotoxic and extremely persistent. Detectable in indoor air over decades.
- Lindane (gamma-HCH): Insecticide against woodworm and house longhorn beetle. Neurotoxic, accumulates in fatty tissue and is suspected of being carcinogenic.
- DDT (dichlorodiphenyltrichloroethane): Broad-spectrum insecticide. Largely banned worldwide, but still detectable in old timber.
- Chloronaphthalenes: Component of older wood preservatives with PCP-like properties. Hepatotoxic.
Well-known product names that contained these active ingredients: Xylamon (old formulations), Xyladecor (old formulations), Basilit and many others. These products were applied to millions of roof structures, beams and panelled surfaces in Austria.
Where are wood preservatives found in Austrian buildings?
In buildings constructed before the 1990s, treated timber elements are the rule rather than the exception. The most common locations:
- Roof structure: The classic case — virtually every roof structure from the 1950s–1980s was chemically treated. Often applied broadly by brush or spray.
- Timber beam ceilings: Visible and concealed beams in older buildings, frequently treated with PCP or lindane.
- Timber-framed buildings: Visible timber framing in historic buildings — wood preservatives were applied as protection against pests.
- Timber panelling: Wall and ceiling panelling from the 1960s–1980s, often stained or painted with wood preservatives.
- Timber staircases: In particular staircase stringers and load-bearing timber elements in older buildings.
Health risk and legal situation
PCP and lindane are not harmless residues from the past. They off-gas from treated timber over decades, enter the indoor air and accumulate in house dust. People who live or work in contaminated spaces take up the substances through breathing and skin contact.
- PCP is classified by the IARC as carcinogenic (Group 1). It damages the liver, immune system and nervous system. PCP is extremely persistent and is broken down only very slowly in the body.
- Lindane is neurotoxic and is suspected of being carcinogenic (IARC Group 1 for lindane since 2015). It accumulates in fatty tissue and in breast milk.
- Both substances bioaccumulate — meaning even low chronic exposures add up in the body.
In Austria, the PCP Ordinance governs the ban on pentachlorophenol. PCP has been banned since 1990. Lindane has not been permitted as a wood preservative since the early 1990s. In existing buildings, however, the treated timber remains — often undetected — as a source of contamination.
How we test for wood preservatives
Whether your timber is contaminated can only be established by laboratory analysis. The colour or condition of the timber gives no indication of the chemical contamination. Our process:
1. Site inspection and sampling
We come in person and inspect all timber elements. Samples are taken as wood chips (material samples). A dust sample can additionally be taken to assess current contamination in the living space.
2. Accredited laboratory analysis (GC-MS)
Samples are analysed by gas chromatography–mass spectrometry (GC-MS) — the standard method for wood preservatives. The laboratory quantifies PCP, lindane, DDT and other active ingredients. For volatile fractions, an indoor air measurement may additionally be advisable.
3. Report and recommendation
You receive a clear report with measured values, assessment and concrete action recommendations: leave in place, seal off, remediate or remove — tailored to your usage situation.
Costs
Every wood preservative measurement is different. Sample type (roof structure, timber framing, interior panelling), the target substance panel (PCP, lindane, DDT or more) and sample count vary significantly. We prepare a transparent quote after the free initial consultation — no obligation.
The site inspection flat fee is €290 (flat, regardless of scope). The video initial consultation is free.
In the free initial consultation we clarify how many samples make sense, so you have clarity on costs in advance.
Frequently asked questions about wood preservative testing
Some wood preservatives have a characteristic chemical smell — PCP and chloronaphthalenes in particular have a musty chemical odour. However, odourless contamination is also possible. Lindane is largely odourless. A noticeable smell in the roof structure is an indication, but only laboratory analysis can reliably confirm and quantify the contamination.
Absolutely. During a loft conversion, treated timber surfaces are exposed, worked and often integrated into the living space. If the roof structure contains PCP or lindane, the pollutants enter the living area via indoor air and dust. An analysis before conversion protects you and your family — and avoids costly post-remediation.
Wood preservative analyses are too situational for a fixed price list — costs depend heavily on sample type (roof structure, timber framing, interior panelling), the target substance panel (PCP, lindane, DDT or more) and sample count. In the free initial consultation we look at your specific situation and prepare a transparent quote. The site inspection flat fee is €290 — flat, regardless of scope.
Yes. PCP has been banned in Austria since 1990 by the PCP Ordinance. Lindane has not been permitted as a wood preservative since the early 1990s. In existing buildings, however, these substances are still present in treated timber and continue to off-gas over decades.
What does wood preservative remediation cost?
Typical remediation costs (indicative figures)
- Seal off / encapsulate roof structure€2,000–€8,000
- Remove timber panelling€1,000–€4,000
- Full roof structure remediation€10,000–€30,000
A wood preservative test gives you clarity — particularly important before a loft conversion. We prepare a transparent quote after a brief initial consultation.
After remediation we offer a verification measurement: indoor air and dust analysis to document that the contamination has been successfully reduced. More on renovation monitoring →