Note: These instructions follow the recommendations of the National Federation of Roofing Contractors Code of Practice governing the use of Liquid Coatings for Roof Waterproofing.
ASPHALT ROOFS
On asphalt roofs where blisters have occurred, these should be heated with a blow lamp until soft and then smoothed out. If the asphalt is crumbling or badly cracked it must be removed and replaced with a polyester based underlay and bonded to the roof deck.
EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING should be applied by brush in 2 coats, the first being allowed to dry before the second is applied.
BUILT-UP FELT ROOFS
Remove any loose chippings and carry out the preparatory work detailed above. Minor marks and defects will be effectively filled and covered by EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING, but where these are wider than 0.75mm they should first be filled with BLACK JACK® BITUMEN MASTIC and the mastic allowed to dry.
Blisters in roofing felt should be opened out, cleaned with a stiff bristle brush and coated with EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING at 1.50 square metres per litre. This coating should be allowed to set until it is “tacky” and then the felt should be re-fixed by bonding it down.
In each case, further coats of EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING and a glass membrane should then be applied
REINFORCED CONCRETE
Carry out preparatory work. New decks should first be allowed to cure and then primed using BLACK JACK® BITUMEN AND FLASHING PRIMER at 4-6 square metres per litre (rate depending upon porosity).
LIGHTWEIGHT CONCRETE
Carry out preparatory work. Allow the concrete roof deck and topping screed to cure. A glass fibre felt underlay should be partially bonded to the surface using BLACK JACK® ROOF FELT ADHESIVE. The felt should be lapped, sealed and adequate ventilation provided for the materials beneath it. EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING and a glass membrane should then be applied.
ASBESTOS-CEMENT SHEETING
Carry out preparatory work. It is particularly important to ensure that the Asbestos-Cement is not saturated with water before protective coating commences. Wait until the Asbestos-Cement sheeting is dry and then apply two coats of EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING, each at 1m² per litre, allowing the first coat to dry before application of the second.
METAL SURFACES
Where these show signs of corrosion such as loose rust this should be removed by abrading with a metal-bristled brush. A rust inhibitive treatment such as Zinc Phosphate Primer should be applied to ensure that the rust does not return. In normal circumstances, abrading with a brush is usually sufficient preparation. EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING should be applied in 2 coats at 1.5 square metres per litre per coat.
SLATES AND TILES
Carry out preparatory work. The roof should be examined for damaged or loose slates or tiles. Any loose slates or sheets should be re-fixed firmly in place. EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING and a glass membrane should then be applied.
ALL WEATHER ROOF COATING AND SCRIM TREATMENTS
In order to bridge gaps, cracks and fissures and in all cases where roof surfaces are in advanced states of decay, it is recommended that EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING be used in conjunction with a reinforcing membrane, either rot-proof hessian or, preferably, a glass membrane.
Having ensured that the surface is clean and receptive to the coating product, apply a first coat at one square metre per litre. Immediately apply the glass membrane into wet EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING film, using a brush charged with further EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING. Ensure that complete contact is achieved and that no air is trapped beneath the membrane.
The glass membrane should be lapped by 50 to 75mm and the inside of each lap should be painted with EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING. Small gaps and differences in levels should be bridged ensuring that the glass membrane is not pulled too tightly across the gap so that any movement in the structure will be accommodated.
At walls and parapets, continue the glass membrane and EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING sandwich vertically for at least 150mm and secure using self-adhesive flashing (150mm width) allowing 75mm to be in contact with the brickwork above. Apply a second coat of EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING and allow this to dry.
FINAL SURFACE
It is beneficial to the coating, and to the rest of the roof structure, to give a final solar reflective finish using BLACK JACK® SOLAR REFLECTIVE PAINT. An exposed black bituminous surface should be avoided on a pitched or flat roof. When using EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING a third and final coat should be preferably applied at 1.5 square metres per litre and, while the film is still “tacky”, well blinded with 1 to 20mm (7 to 14 mesh) stone chippings or clean sharp sand. Alternatively, wait for a minimum of 3 days, preferably 2 weeks, then apply a solar reflective coating using BLACK JACK® SOLAR REFLECTIVE PAINT.
VAPOUR BARRIER
When insulating material is placed on a flat roof deck it is essential to prevent condensation water vapour from entering the insulation. If this is allowed to happen it can damage the insulation. Two coats of EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING, the first applied at one square metre per litre, the second at 1.5 square metres per litre, will help prevent this. EVERBUILD® BLACK JACK® 905 ALL WEATHER ROOF COATING should be applied to the “warm side”, with care being taken to avoid pin holes and imperfections in the coating. When dry, the insulation may be applied over it.
