Sika Black Jack 300mm Grey Flashing Tape 10m Roll FLAS300

Product Details: Brand: Sika | Range: Black Jack | Product Type: Self-Adhesive Flashing Tape | Size: 10m x 300mm | Colour: Grey | Product Code: FLAS300 | SKU: 482962 | MPN: FLAS300 | Sika Code: 852565 | EAN: 5029347099053

Sika Black Jack Self-Adhesive Flashing Tape 10m x 300mm is a wide grey flashing tape with a lead-look finish for larger roof repairs, wide flashing laps, parapet details, skylight edges, gutter seams, roof sheet overlaps and broader waterproofing jobs. It combines an aluminium foil face with a bitumen rubber adhesive backing, helping form a waterproof seal when pressed firmly onto a clean, dry and suitable prepared surface.

The 300mm width gives more coverage than the 225mm roll and is useful where a wider repair strip can reduce the number of separate tape runs needed. It is suited to larger seams, wider overlaps and broader roof details where smaller widths may need extra joins or more careful matching between strips.

Where This 300mm Flashing Tape Fits

This 300mm roll is suited to wider repair areas where coverage, alignment and fewer joins are more important than narrow detail placement.

• Sealing wide roof seams, joints and flashing laps.
• Repairing larger flashing sections around roof edges and upstands.
• Waterproofing wider gutter details, gutter edges and larger leak points.
• Covering broader roof sheet overlaps, fixings and sheet edge details.
• Flashing parapet walls, skylight edges, roof glazing areas and wider abutments.
• Sealing larger cracks or repair zones on suitable prepared concrete or building surfaces.
• Creating a wide grey lead-look waterproofing strip on suitable prepared surfaces.

Why Choose The 300mm Width

Choose the 300mm roll when the repair needs a wide strip of flashing tape but does not require the maximum width of the 450mm roll. It gives strong coverage for larger roof details, broad flashing overlaps, parapet work, skylight edges and wider gutter repairs.

For smaller seams, capping bolts or narrow details, the 75mm or 100mm rolls will usually be easier to handle. For medium-width flashing work, the 150mm or 225mm sizes may be enough. For very large patch repairs, broad abutments or maximum coverage in one strip, the 450mm roll may be more suitable.

Key Performance Benefits

• Wide Repair Coverage: The 300mm width covers larger roof seams, flashing laps and broader waterproofing areas.
• Fewer Tape Runs: The wider format can reduce the need for multiple narrow strips on larger repair zones.
• Self-Adhesive Backing: The bitumen rubber adhesive backing removes the need for a separate adhesive on suitable prepared surfaces.
• Grey Lead-Look Finish: The aluminium foil face gives a lead-look appearance for roof and flashing repair work.
• 10m Roll Length: The roll provides enough material for wide repair runs or repeated larger maintenance tasks.
• Cut-To-Length Use: The tape can be measured and cut to suit the repair before the backing is removed.

Applying The 300mm Tape On Wide Repair Areas

The 300mm roll covers a large area in one pass, so placement needs to be planned before the adhesive backing is exposed. A wider strip can be harder to reposition once it starts to bond, so set the tape out, check the line of the repair and work steadily as the backing is removed.

• Step 1: Clean the full repair area, including the outer edges of where the 300mm strip will sit.
• Step 2: Make sure the surface is dry, sound and stable before fitting the tape.
• Step 3: Prime porous surfaces such as brick, blockwork or concrete where required, then allow the primer to dry.
• Step 4: Measure the repair run and cut the tape to length while the release backing is still in place.
• Step 5: Offer the cut strip into position first, especially on long roof edges, parapet details, skylight runs and broad flashing overlaps.
• Step 6: Expose a short starter section of adhesive, fix one end in place, then pull the backing away gradually while pressing the tape down.
• Step 7: Work from the centre towards both edges, then roll the full width so the edges, corners and overlap points are sealed properly.

When 300mm Flashing Tape Is Not The Best Fit

This 300mm flashing tape is designed for wider external sealing and repair work. It should not be used where the surface cannot be prepared properly or where a smaller or wider tape size would be more suitable.

• Do not apply to: Damp, wet, dirty, oily, greasy, loose, crumbling or unstable surfaces.
• Prime first where needed: Porous brick, blockwork, concrete and similar absorbent surfaces may need Sika Black Jack Bitumen and Flashing Primer before application.
• Use a narrower roll instead: For capping bolts, small seams, narrow gutter details or tight repair points, 75mm, 100mm, 150mm or 225mm tape may be easier to position.
• Use 450mm instead: For very large patch repairs, broad abutments or maximum-width roof coverage, the 450mm roll may be more suitable.

Technical Application Notes For 300mm Tape

The following application points are based on manufacturer technical guidance and should be checked against the current data sheet before use.

• Use within the manufacturer-stated application temperature range of 5°C to 40°C.
• Do not apply over damp, wet, dirty, loose or unstable material.
• Clean beyond the visible repair so the whole 300mm width lands on a properly prepared surface.
• Remove dust, loose particles, oil, grease and surface contamination before positioning the tape.
• Prime porous brick, blockwork, concrete or similar absorbent surfaces where required, then allow the primer to dry before applying the tape.
• Measure the repair area first and cut the tape to length before removing the release backing.
• Set the strip into position before bonding, especially on wider roof seams, parapet runs, skylight edges and roof sheet overlaps.
• Use at least 25mm overlaps where separate sections of tape meet.
• Remove the backing gradually so the wide strip stays controlled and does not fold back onto itself.
• Keep the loose section supported while applying it, especially on longer cut lengths.
• Press from the centre out towards both edges to push trapped air away from the middle of the repair.
• Roll across the full 300mm width, including the outer edges, corners and overlap points.
• Check upstands, gutter edges, roof sheet profiles, corners and changes in surface level carefully, as wide tape needs firm contact across the whole strip.
• In cold weather or after cold storage, adhesion may be reduced. Allow the tape to warm up or gently warm the bitumen adhesive layer with a hot air blower if needed.
• Always check the current manufacturer technical data sheet before use.

Products To Help With Preparation And Clean-Up

For porous brick, blockwork or concrete areas, prepare the surface with Sika Black Jack 902 Bitumen and Flashing Primer 1L before applying the tape.

For cleaning hands, tools or nearby marks after cutting, handling and pressing the wide strip into place, use Heavy Duty Sika Everbuild Textured Wonder Wipes – 75 Wipe Tub.

• Specification

  Weight	3 kg
  Manufacturer	Sika
  Reference Code	FLAS300
  Reference Code sika	852565
  Length	10 Meter
  Width	300mm
  Colour	Grey

• Product FAQs

  Q: What is Sika Black Jack 300mm Grey Flashing Tape used for?
  A: It is used for wide roof seams, larger flashing laps, parapet areas, skylight edges, gutter details, roof sheet overlaps and broader waterproofing repairs.
  Q: What size is this flashing tape?
  A: This roll is 10 metres long and 300mm wide.
  Q: When should I choose 300mm flashing tape?
  A: Choose 300mm tape for wide roof joints, parapet details, skylights, gutter details, roof sheet overlaps and repair areas where 225mm tape may not provide enough coverage.
  Q: Does this flashing tape need separate adhesive?
  A: No. It has a self-adhesive bitumen rubber backing but porous surfaces may need priming before application.
  Q: What surfaces can it be used on?
  A: It can be used on suitable prepared surfaces such as concrete brick metal timber roofing felt and similar building materials.
  Q: How does 300mm compare with 450mm flashing tape?
  A: The 300mm tape provides wide coverage for larger repairs while being easier to handle than a 450mm roll on many roof and gutter details.

• Downloads

  Everbuild Flashing Tape Black Jack Instructions Technical Data Sheet
  Everbuild Flashing Tape Black Jack Safety Data Sheet
  Sika Black Jack Flashing Tape Technical Data Sheet