Asbestos or eternit roof removal: cleanup techniques

According to the latest legal regulations, asbestos-containing materials (ACM) or Eternit (also known as fiber-cement, a material composed of a mixture of cement and asbestos fibers) must be removed because asbestos consists of mineral fibers that are extremely harmful to health.

The greatest risk occurs when asbestos deteriorates or is damaged: it releases fibers into the environment that can remain suspended in the air and be inhaled, compromising the health of those exposed to this mineral.

A significant factor in assessing health risks from asbestos exposure is the friability of the materials. Asbestos-containing materials (ACM) can be classified according to D.M. 06/09/1994 as either friable (easily crumbled or reduced to powder with simple manual pressure) or non-friable (can only be crumbled or reduced to powder with the use of mechanical tools such as abrasive discs, milling machines, and drills).

Asbestos or eternit roof removal: the importance of cleanup techniques

Asbestos removal is the ideal technique when the material is deteriorated, damaged, or when it is no longer economically viable to maintain the roofing. This method involves the complete removal of asbestos-containing sheets or materials. The operation must be conducted while preserving the integrity of the material throughout all phases, from disassembly to lifting, from initial packaging to ground placement (using appropriate mechanical means), and until final packaging.

Here are the essential steps:

1. Site Preparation: The work area is demarcated using barriers and signs to prevent unauthorized access. Workers must wear personal protective equipment (PPE).
2. Wetting the Material: Before removal, the material is wetted with an encapsulating solution (composed of water and a vinyl solution) to reduce the release of fibers.
3. Dismantling: The asbestos-containing material is carefully removed, avoiding breakage and the subsequent release of fibers.
4. Packaging: The removed material is collected in big bags or pallets and sealed with secure, transparent, labeled tarps, and then disposed of in authorized landfills.
5. Site Cleaning: After removal, the area is thoroughly cleaned and monitored to ensure no residual asbestos fibers remain.

Removal is the most expensive technique, requiring time and meticulous attention since fibers can be released during the process. It involves disposal in authorized landfills and sometimes necessitates halting building operations.

2 – Encapsulation

Encapsulation is a recommended technique when removal is not yet necessary because the asbestos material is in good condition and not subject to damage. Being less invasive, more cost-effective, and quicker than removal, encapsulation poses a very low risk to workers.

This method involves treating asbestos surfaces with penetrating or covering products (known as “encapsulants”) that can embed the fibers and form a protective film on the surface. This film prevents the release of asbestos fibers into the air. The structure with asbestos elements can continue to be used during the intervention.

Here are the main steps of encapsulation:

1. Application of the Encapsulant: A special sealing product (such as a spray) is used to create a film that prevents fiber dispersion.
2. Seal Integrity Check: Once dry, the encapsulated material is inspected to ensure it has been adequately sealed.

Encapsulation uses impregnating products that penetrate the material, binding the asbestos fibers together and with the cement matrix, and covering products that form a thick membrane on the surface of the item. These products may also contain pigments and substances that enhance resistance to weathering.

Drawbacks of This Technique:

• Encapsulation does not remove asbestos but isolates it.
• It requires periodic inspections to ensure the protective coating remains intact over time.
• Encapsulation is not recommended for friable asbestos-containing materials (ACM) because increasing the structural weight can exacerbate the natural tendency toward deterioration.

3 – Confinement

Confinement, also known as over-covering for Eternit roofs, involves covering asbestos-containing material with another material to create a barrier that prevents fiber dispersion. This is achieved by installing a new layer of roofing over the existing one or by using panels or coverings that form a solid barrier between the asbestos and the occupied areas of the building.

This technique can only be used if the supporting structure can bear the additional load of the new covering.

Like encapsulation, confinement is less expensive than removal and reduces the risk of fiber exposure. It is an ideal solution when removal is not possible or convenient, when the existing roof is still in good condition, or when removal needs to be delayed.

Here are the necessary steps for confinement:

1. Barrier Construction: Install a new covering, often made of metal sheets or prefabricated panels, which isolates the asbestos from the surrounding area.
2. Stability Check: Ensure that the structure is stable and does not allow for fiber dispersion.
3. Periodic Maintenance: Regular monitoring and maintenance are required to ensure long-term safety.

Drawbacks of Confinement:

• Like encapsulation, confinement does not eliminate asbestos but only isolates it.
• Future interventions may require the removal of both the new covering and the original asbestos-containing material.

As seen, the choice of technique depends on various factors, such as the condition of the asbestos, access to the roof, costs, and local regulations. Removal is generally preferred because it minimizes risk but is also the most expensive and complex. Encapsulation and confinement are temporary solutions that require constant monitoring and regular maintenance.

Asbestos or eternit roof removal: choose TOPTAGLIO