Greengates Builders Merchants

310ml General Purpose Mastic Sealant Cartridge- Brown


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115 GP Building Mastic is an oil based compound intended for general pointing and sealing of many joints in traditional forms of construc­tion. The sealant is rapidly and simply applied by extrusion from a cartridge gun. The product has good adhesion to most clean, dry surfaces,



  • Overpa­in­table
  • Adheres to most common surfaces
  • Semi drying – remains permanently elastic beneath surface skin
  • High solids formulation – excellent gap filling properties without shrinkage
  • Good external weathering properties


Areas for use:

  • Perimeter pointing internally and externally around doors and windows
  • Adheres to concrete, brick, wood, metals and glass without the use of a primer


Areas not for use:

  • In areas likely to be exposed to solvents, petrol’s or oils.
  • Fresh concrete or mortar. Allow 28 days to reduce surface alkalinity
  • In conjunction with bitumen or asphalt – use Weathermate Sealant
  • May stain marble, slate or certain sensitive natural stone
  • On Upvc, polyc­ar­bonate or acrylic sheet
  • The product takes 24-48 hours to skin, but 2-4weeks to through cure. It should therefore not be used in areas where it is likely to be subjected to interference or damage e.g. floor joints.



  1. Cut the tip of the cartridge taking care not to damage the thread. Apply nozzle and cut at an angle of 45˚ with an opening slightly larger than the gap to be sealed. Apply using a standard sealant gun.
  2. Best results will be obtained by keeping an even pressure on the trigger and keeping the gun at a constant angle to the surface being sealed.
  3. To ensure a proper bond, always smooth the sealant down with a spatula or piece of wood wetted with linseed oil or white spirits.
  4. An improved joint appearance can be achieved by placing masking tape to both sides of the joint, removing within 5minutes of application.


Health & Safety

Not considered as hazardous to health during normal use. Avoid unnecessary skin contact. Remove with soap and water. If product enters eyes, rinse immediately with soap and water. Seek medical advice if irritation persists.

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Area Covered

Deliveries can be made throughout most of Lancashire, appro­ximately 20 miles radius from our depot at Accrington, Lancashire.

Other locations may also be arranged for direct loads from our suppliers e.g. full loads of bricks or blocks.

Vehicle Types

We operate 3 crane offload vehicles:

  • Our smallest vehicle can carry approx 5 ton.
  • Our middle sized vehicle can carry approx 7.0 ton and has a tipping facility for loose sand and aggregates.
  • Our largest vehicle can carry approx 8.0 ton and also has a tipper facility.


Pricing will vary depending on the goods required and distance travelled.

We can offer very competitive rates for delivery — please contact us for more details.