Sika® Black Jack®-905 All Weather Roof Coating

Oxidised bitumen in white spirit.

24 months from date of manufacture in unopened and undamaged containers.

Contains a flammable solvent and all precautions against fire must be taken during storage. Store between +5 and +25 °C.  

ca. 1.0 g/cm³ at +20 °C.

Wet product is flammable, dry film will burn.

Resistant to: most salt solutions, dilute acids and alkali, and water.
Not resistant to: oils, solvents and some detergent solutions. 
If not sure, check first in an inconspicuous area.

-10 °C to +85 °C.

The cured film will not sag or flow under normal conditions.

+5 °C to +40 °C. Surfaces must be free from ice and water.

+5 °C to +40 °C. Surfaces must be free from ice and water.

24 hours depending on drying conditions. Allow 24 hours between coats.

Approx. 1.25 m² per litre per coat depending on porosity of substrate. Two coats should give a dried film of approximately 0.9 mm.

No roof coating product can be expected to repair an existing roof that is not structurally sound and stable. Before using a surface coating the roof structure should be inspected and, if necessary, put in order. All cracked, broken, slipped or missing slates, tiles, sheets or other forms of covering should be replaced or re-fixed, and cracks in felt or asphalt filled.

Safety Recommendation: do not coat roof lights, windows, glass or translucent sheets. These will constitute a hidden hazard if disguised.
Preparation of the surface is of great importance and will influence the degree of adhesion and life of the renovation. All roof surfaces to be coated should be sound, stable and clean, i.e. free from loose debris, dirt, dust and grease. Where there is green growth present, clean surfaces with Sika® Mouldbuster as directed, before proceeding.

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. Ensure you stir the product well before use.
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 rot-proof hessian reinforcement scrim or bitumen coated glass fibre scrim such as a fibre glass membrane. Sika® 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 Sika® Black Jack®-905 All Weather Roof Coating, but where these are wider than 0.75 mm they should first be filled with Black Jack®-903 Bitumen Trowel Mastic and the mastic allowed to dry. Blisters in roofing felt should be opened out, cleaned with a stiff bristle brush and coated with Sika® Black Jack®-905 All Weather Roof Coating at 1.25 m²/L. 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 Sika® Black Jack®-905 All Weather Roof Coating and a glass fibre 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 m²/L (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 Sika® Black Jack®-905 All Weather Roof Coating. The felt should be lapped, sealed and adequate ventilation provided for the materials beneath it. Sika® Black Jack®-905 All Weather Roof Coating and a glass fibre membrane should then be applied.
CEMENT SHEETING
Carry out preparatory work. It is particularly important to ensure that the cement is not saturated with water before protective coating commences. Wait until the cement sheet is dry and then apply two coats of Sika® Black Jack®-905 All Weather Roof Coating, each at 1 m²/L, 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. Sika® Black Jack®-905 All Weather Roof Coating should be applied in 2 coats at 1.25 m²/L 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. Sika® Black Jack®-905 All Weather Roof Coating and a glass fibre 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 Sika® Black Jack®-905 All Weather Roof Coating be used in conjunction with a reinforcing membrane, either rot-proof hessian or, preferably, a bitumen-coated fibreglass membrane. Having ensured that the surface is clean and receptive to the coating product, apply a first coat at 1 m²/L. Immediately apply the bitumen-coated fibreglass membrane into wet Sika® Black Jack®-905 All Weather Roof Coating film, using a brush charged with further Sika® Black Jack®-905 All Weather Roof Coating. Ensure that complete contact is achieved and that no air is trapped beneath the membrane. The bitumen glassfibre membrane should be lapped by 50 to 75 mm and the inside of each lap should be painted with Sika® Black Jack®-905 All Weather Roof Coating. Small gaps and differences in levels should be bridged ensuring that the bitumen glassfibre 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 bitumen glassfibre membrane and Sika® Black Jack®-905 All Weather Roof Coating sandwich vertically for at least 150 mm and secure using self-adhesive flashing (150 mm width) allowing 75 mm to be in contact with the brickwork above. Apply a second coat of Sika® 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 Sika® Black Jack®-905 All Weather Roof Coating a third and final coat should be preferably applied at 1.25 m²/L and, while the film is still “tacky”, well blinded with 1 to 20 mm (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®-907 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 Sika® Black Jack®-905 All Weather Roof Coating, the first applied at 1 m²/L, the second at 1.25 m²/L, will help prevent this. Sika® 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.

All tools should be cleaned immediately after use with Sika® Wonder Wipes or white spirit. Any spillage should be wiped off surfaces before the bitumen has set.