Does my roof contain asbestos?
Short answer. A roof made of fibre-cement slates (also called artificial slates) or corrugated fibre-cement sheets laid before the end of 1998 may contain asbestos: asbestos cement has been banned in Belgium since 1 October 1998. A roof that contains asbestos is never cleared of moss or cleaned, whatever the method. Only a laboratory analysis settles the question.
Updated on 20 October 2026
Which roofs are concerned?
Asbestos used to be present in fibre-cement products, often called "eternit" after the main manufacturer:
- fibre-cement slates (artificial slates), flat and regular, often grey;
- corrugated sheets, on outbuildings, garages and shelters.
Clay tiles and natural slates, which are stone, are not affected.
Recognising a slate without asbestos
The manufacturer Eternit states:
- that it has not used asbestos since June 1997;
- that its first slates without asbestos date from 1988, and that none of its slates has contained asbestos since 1996;
- that the 60 x 40, 60 x 32 and 45 x 32 cm sizes never contained asbestos;
- that its products without asbestos carry, most of the time, the marking NT.
"Most of the time" only: the NT marking applies to this manufacturer, others used other codes, and the absence of a marking proves nothing. If in doubt, a laboratory analysis settles it.
Why we do not remove moss from an asbestos-cement roof
Moss anchors itself with rhizoids, fine roots that penetrate the gaps in the material. Tearing it off also tears off fibres, which end up in the air, in the gutters and in the garden. This is why Buildwise, the construction industry's technical centre, considers that any moss removal on an asbestos roof is prohibited, even without high pressure. The rules, Region by Region:
| What the authorities say | |
|---|---|
| Belgium, on building sites | The Code on Well-being at Work prohibits high-pressure cleaners on materials that contain asbestos. The FPS Employment (SPF Emploi) asks that moss not be removed from these roofs. |
| Flanders | Since 27 April 2019, removing moss from or cleaning an asbestos-cement roof or facade is prohibited for everyone, private individuals and professionals alike, whatever the technique. Installing solar panels or an overlay roof on it is also prohibited. |
| Brussels | Brussels Environment (Bruxelles Environnement) prohibits high-speed tools, high pressure, dry blasting and even chemical products on asbestos. |
| Wallonia | It is prohibited to clean a roof that contains asbestos with a high-pressure cleaner. |
Our rule is simple: no moss removal, no cleaning, no treatment on a roof that may contain asbestos, until an analysis has shown otherwise.
What should you do with an asbestos-cement roof?
Leave it as it is. According to Eternit, moss does not damage its corrugated sheets. It is mainly the work done on them that releases fibres: cleaning, drilling, cutting or breaking the material.
Have it removed. This is the solution the authorities favour. By Region:
- Flanders: every municipality organises home collection of asbestos cement (about €30 to €40 per bag and €170 per container according to OVAM, varying by inter-municipal body). Since 23 November 2022, an asbestos certificate has been compulsory to sell a building constructed before 2001, and OVAM aims for the removal of asbestos-cement roofs by 2034. The Mijn VerbouwPremie provides a supplement for asbestos removal combined with roof insulation.
- Wallonia: small solid items, such as a corrugated sheet, can be taken down without being broken and dropped at the recycling centre (recyparc), which can supply suitable bags; the conditions depend on the inter-municipal body.
- Brussels: an asbestos inventory is compulsory before a renovation job, and the Region does not subsidise removal.
For a whole roof, call a company specialised in asbestos removal. That is not our line of work.
Frequently asked questions
How can I tell if my slates contain asbestos?
Look at the date of installation and the material: fibre-cement slates laid before 1998 are suspect. The NT marking most often indicates an Eternit slate without asbestos, and some sizes never contained any. Only a laboratory analysis gives a certain answer.
Can you remove moss from an asbestos roof with a product, without high pressure?
No. Buildwise considers any moss removal on an asbestos roof prohibited, even without high-pressure rinsing, and Brussels Environment also prohibits chemical products on asbestos. In Flanders, the law prohibits every technique.
Can an asbestos-cement roof be painted?
We do not do it: painting requires cleaning first, and that cleaning is prohibited.
Is there a grant for removing an asbestos roof?
In Flanders, a supplement to the Mijn VerbouwPremie if the removal is combined with roof insulation (income categories 3 and 4 since 1 March 2026), and a paid municipal collection. In Brussels, no regional aid for removal. In Wallonia, neither the Region's page on asbestos nor the announcement of its new loan scheme mentions any aid for asbestos removal from roofs. See also Grants for roofs in 2026.
Sources
- Buildwise, Can moss be removed from a roof that contains asbestos? (in French)
- FPS Employment (SPF Emploi), Questions and answers on asbestos (in French); Code on Well-being at Work, book VI, title 3.
- OVAM, Wetgeving en handhaving, Het asbestattest, Actieplan asbestafbouw (in Dutch).
- Brussels Environment, Asbestos: how to avoid health risks? (in French)
- Wallonia, Finding out about the health risks linked to asbestos exposure (in French)
- Eternit, The history of asbestos (in French)