How to apply Everbuild Black Jack 905 All Weather Roof Coating

A step-by-step guide for waterproofing and protecting your roof

If you’ve noticed damp spots or small cracks after heavy rain, you can often fix the issue yourself with the right roof coating. Everbuild Black Jack 905 All Weather Roof Coating is a high-performance, bitumen-based formula that seals and protects a wide range of roof surfaces, including felt, concrete, slate, metal, and corrugated sheeting.

With the right preparation, it’s easy to apply and provides a flexible, long-lasting waterproof finish.

Here’s a quick run-down of what you’ll need and the steps involved before you start applying Everbuild Black Jack 905.

What you’ll need:

• Everbuild Black Jack 905 All Weather Roof Coating
• Brush or roller (with extension handle for larger areas)
• Paint tray or bucket
• Stiff brush or pressure washer for cleaning
• Suitable cleaner for tools
• Optional: Everbuild Black Jack 903 Bitumen Trowel Mastic (for repairs)
• Optional: Everbuild Black Jack Flashing Tape (for joints and edges)

What you’ll be doing:

1. Clean and dry the roof surface thoroughly.
2. Repair cracks or blisters with Black Jack 903 Bitumen Trowel Mastic.
3. Seal joints and corners using Black Jack Flashing Tape.
4. Stir the coating well and apply evenly with a brush or roller (approx. 1 L per m²).
5. Allow to dry for 24–48 hours before checking the finish or adding a second coat.
6. Clean tools immediately and let the coating cure fully before exposing it to rain or foot traffic.

Before you begin

Check these key details before you get started:

• Ideal temperature: Between 5°C and 30°C
• Surface condition: Clean and completely dry
• Drying time: 24–48 hours depending on weather and coating thickness
• Preparation: Stir thoroughly before use

Although it’s an “all-weather” formula, applying on a dry day ensures better adhesion and a smoother finish.

Preparing the roof

Start by cleaning the roof thoroughly. Remove dirt, dust, moss, and debris using a stiff brush, or use a pressure washer for heavy grime. Allow the surface to dry fully before applying the coating.

Inspect the roof carefully for cracks, small holes, or loose areas that need repair. It’s a good idea to fix these before applying the main coating. For patching gaps or blisters, Everbuild Black Jack 903 Bitumen Trowel Mastic is ideal. It spreads easily and creates a smooth, sealed surface.

Around joints, corners, vents, and chimneys, reinforce with Everbuild Black Jack Flashing Tape for extra waterproof protection. Press it down firmly, smooth out air bubbles, and then apply the roof coating over the top for a continuous seal.

Applying the coating

Stir the product thoroughly before use so the fibres are evenly mixed. Pour into a paint tray, cut in around edges with a brush, and use a wide roller for open areas.

Apply evenly at around one litre per square metre, avoiding puddles or thick patches – the coating will self-level as it cures.

For very porous or weathered surfaces, a second coat can enhance protection. Allow the first coat to dry for roughly 24 hours before applying another layer.

Top tip: As this is a solvent-based coating, clean brushes and rollers immediately using an appropriate cleaner. Keep your workspace well-ventilated and away from open flames or sparks until the surface has cured.

Curing and clean up

Once applied, allow the coating to cure fully, usually within 24 to 48 hours. Avoid walking on the roof or exposing it to rain until it has completely cured.

You’ll know it’s cured when the surface changes from tacky to firm and dry to the touch, with a smooth, even, and slightly glossy finish. If it still feels sticky or leaves a mark when lightly pressed with a gloved finger, it needs more time to cure.

The finished result

When the coating has dried, you’ll immediately notice the difference. Rainwater will bead and run off the surface instead of soaking in, and the finish will look clean and uniform. The coating forms a flexible barrier that helps protect your roof from water damage, UV light, and temperature extremes.

With regular inspection and the occasional touch-up, a single application can keep your roof protected for years to come.

Find Everbuild Black Jack 905 All Weather Roof Coating and the full range of Everbuild Black Jack products here. Order by 2 pm for next-working-day dispatch on stock items, and get everything you need for a lasting, weather-proof roof finish.