Asbestos Roof Sealer and Primer
Developed primarily as a remedial treatment to improve the safety of corrugated asbestos cement roof sheets, Asbestos Roof Sealer and Primer is a fine liquid acrylic-ester dispersion, which helps to suppress dust and limit the release of potentially hazardous, chrysotile asbestos fibres. It has the approximate consistency of water and absorbs readily into porous asbestos roof sheets and profile cladding.
• Helps to lock away harmful asbestos fibres
• Apply by brush or low-pressure spray (e.g. manual pump)
• Perfect pre-treatment for Kingfisher Asbestos Roof Coating
• Improves water resilience
• Non-dusting, clear finish
• Provides a surface seal with no material build-up
• Solvent free asbestos roof sealant
• Can reduce need for specialist asbestos removal
• Coverage: 4-6m² / litre per coat
• Exterior & interior asbestos cement (AC) sealer
Managing asbestos in buildings is a legislated obligation for property owners and is of particular concern for those involved in letting, occupying, marketing or maintaining commercial and industrial properties. This is largely because asbestos cement was used very extensively in such buildings for decades, before the full extent of its toxicity was properly understood.
Asbestos containing materials (ACMs) are also found in domestic flats and houses, although generally to a lesser extent.
As a versatile and heat resistant material, it was used in its varied forms in the manufacture of heat shields, gaskets, heating plant, flooring and roofing to name but a few. And since it was never going to be practical or indeed necessary to remove all asbestos after it was banned in 1999, the focus since then, has been on managing the risks associated with it, several of which pertain to asbestos cement (AC) roof sheets. Asbestos Roof Sealer & Primer can help with managing these risks, either as a stand-alone treatment or more commonly as a pre-treatment for our encapsulating
Kingfisher Asbestos Roof Coating.
How does it work?
Asbestos Roof Sealer and Primer is manufactured using a very fine dispersion acrylic-ester which soaks into the substrate of asbestos roof sheets. This ability to penetrate, or “carry” further into the material substrate, is the key to stabilising or consolidating the hazardous fibres contained therein. As it cures, the acrylic resin binds the loose surface particles, rather like an adhesive and greatly reduces the possibility of harmful fibre release. It also provides a perfect base for
Kingfisher Asbestos Roof
Coating which is a companion waterproof, elastomeric coating with a 10-year lifespan.
• Sealing of industrial asbestos roofs
• Seals “Big 6” and smaller gauge corrugated asbestos profiles
• Renovation of asbestos roofs of all ages
• Sealing of garage & warehouse roofs internally
• Ideal sealant for asbestos roofs used in storage
Here in the U.K, asbestos roof sheets were manufactured and installed for most of the 20th Century. The familiar corrugated profile sheets helped thousands of military buildings to be rapidly assembled in kit form during WW2, and these can still be found to this day, scattered throughout the country. The point is that asbestos cement roofing (white asbestos) is a very durable material, which in a majority of cases has outlived its anticipated lifespan by decades. In fact Kingfisher has been involved in supplying sealers and coatings to roofs which date as far back as the 1930s! This means that building maintenance professionals and property owners are likely to be maintaining asbestos roofs for many years to come.
Repair or Replace?
Although the “white asbestos” (chrysotile) used in the manufacture of roofing sheets was the least toxic asbestos variant, it is still has the potential to be hazardous, which is why the management and removal protocols are strictly enforced. The cost of complete removal and replacement of asbestos cement roof sheets, can therefore be considerable, often prompting stakeholders to consider repair options. The repair option includes using a roof sealant spray such as our Kingfisher Asbestos Sealer & Primer which reduces the upheaval of asbestos removal and the costs involved.
The second option considered, especially in storage or agricultural buildings is to simply replace the asbestos sheets with modern plastisol coated, steel profile sheeting. However, it is worth remembering that one of the major reasons why asbestos cement roof sheets became so popular in the first place, was that compared to corrugated “tin” (steel profile), they did not suffer from condensation. By contrast, “tin” roofed buildings famously rained condensation on workers, stock, machinery, farm animals or anything else unfortunate enough to be inside.
Of course, you can opt for composite insulated panels that won’t exhibit condensation but they are at least 2.5 times the cost! Or you can choose modern cement fibre roof sheets (nearest equivalent to the old AC sheets) but these are also more costly than steel profile. So for example, if you store your classic car in a garage with an asbestos roof, it may be that this is as at least as good an option as modern cement fibre and definitely better than new steel profile. Repair & re-coating should at the very least be considered.
Another area to consider is the inside of asbestos roofs & cladding. Customers often contact Kingfisher, reporting that they have “asbestos dust” occasionally falling from the roof sheets. Analysis of such dust generally reveals microscopic cement deposits rather than chrysotile fibres but nevertheless it is relatively simply to spray the underside of the roof with Asbestos Roof Sealer and Primer to seal against dusting. It is not necessary to follow up with an encapsulating coating as this “ceiling face” suffers neither weathering nor abrasion.
How to use Asbestos Roof Sealer and Primer?
1. Bio Wash Roof (kills moss, green mould & lichens)
Liberally spray the entire roof surface with Kingfisher Bio Wash using a low-pressure sprayer (as for garden weed-killer) and leave for seven days to activate.
2. Clean Roof (remove debris)
Thoroughly damp the roof by mist spraying with water (suppresses release of harmful fibres) and brush/ scrape the dead moss and other surface dirt and laitance into bags for disposal as AC waste. Alternatively for larger areas the “closed box” pressure washing method described in HSE doc A12 can be used but the waste sludge and water run- off have to be collected in the gutters and down pipe.
3. Repair Roof General
Sealers and coatings should only be applied to essentially “sound” roofs so a pre-inspection of the roof structure and surface condition should always be undertaken by a competent person (e.g. experienced roofing contractor or structural engineer) before commencing works. This will determine whether the supporting steel / timbers are in need of repair and identify any cladding / roof sheets which are damaged or decayed beyond practical repair and therefore need complete replacement. In addition, this inspection will typically inform the choice of access equipment to be used for safe execution of the works.
4. Minor Repairs
Any minor cracks or holes, especially around fixings can be filled with
Parabond hybrid polymer sealant. Cracks of up to 3mm can be successfully filled by applying a bead of Parabond along the crack and then pressing / smearing it firmly into the damaged area.
5. Larger Repairs
Bigger cracks or holes can be bridged with
Kingfisher Fibreseal fibre reinforced roofing compound &
Kingfisher Scrim Mesh.
6. Application (External)
Supplied ready to use, the product can be applied by brush or low pressure (non-atomising) spray. One coat should normally be sufficient when used as a primer but when used as a stand-alone sealer in exterior applications, two coats are usually preferable.
7. Application (Internal)
As described above “dusting” in the form of a light grey particle dust is sometimes observed beneath AC roofs. Supplied ready to use, Kingfisher Asbestos Sealer & Primer can be applied by brush or low pressure (non-atomising) spray. One application should normally be sufficient but if in doubt apply to a test area and once cured check that brushing with a clean, dry paint brush does not release any dust. A major advantage compared to painting is that being a clear water-based acrylic, any over-spray or over-brushing on beams, purlins and light fittings etc. is not nearly as obvious as a paint, saving time on “masking off” precautions.
How much will I need?
The coverage rate is 4 to 6 sq. m per litre, so a 25 litre drum treats approximately 125 sq. m.
a) Do not apply to damp surfaces or in wet weather.
b) Always consult a competent Health & Safety professional for guidance on working at height, especially on fragile surfaces like AC sheeting.
c) Ensure you inform yourself regarding correct PPE and waste disposal protocols for working with asbestos cement roof sheets.
As always we recommend that you read the Technical Data Sheet & Safety Data Sheet thoroughly before commencing any work. If in doubt please call us for advice, we are here to help.
does what it says on the tin
used to seal under side of roof .works well.
Reviewed by Mr Brian Grantham on
I applied this to parts of our garage roof after cleaning off the moss. It is really easy to use (quite thin) and seemed to make it easier to brush on the "asbestos roof coating" which was also in the kit I bought.
Reviewed by Andy Tillman on