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Everbuild Everflex Premium+ 450 Builders Silicone C3

Our Price:
£58.50 £70.20 inc VAT
£102.60 inc VAT


Product Code: EV450-25-C3-CART

Product Description

450 Builders Silicone is a premium quality low modulus non-corrosive neutral cure silicone sealant that adheres to virtually all substrates, both porous and non-porous.

everFLEX SILICONE 450 PREMIUM BUILDERS SILICONE is a low modulus, neutral cure RTV silicone sealant that adheres to a wide range of both porous and non porous surfaces without the need for priming. Conforms to ISO11600 F25 LM.


  • Excellent adhesion - adheres to most common surfaces including glass, metals, plastics and wood
  • Low dirt pick up - important in PVCu  work
  • Excellent flexibility - +/- 25%.
  • High resistance to plasticiser migration - may be used over water based and solvent based paints.
  • Excellent external weathering properties.
  • Suitable for use on polycarbonate


 Areas For Use

  • Perimeter pointing internally and externally around PVCu /wood and all other window frames.
  • Sealing and as an adhesive onto PVCu, plastic trims and components.
  • Bedding insulated glass units in accordance with relevant clauses of BS8000 Part 7.
  • Suitable as an expansion joint sealant.
  • Weather sealing and joint sealing to pre-formed panels.
  • Sealing soft metals such as lead, copper and zinc.
  • General glazing sealing and draughtproofing, including repair work over existing sealant.
  • Glass to glass and glass to aluminium sealing.
  • Parapet and roof weather sealing applications.



  • Do not use in conjunction with bitumen asphalt, neoprene and certain organic elastomers.
  • Do not use in the manufacture of Aquariums. Use AQUA MATE
  • Do not use on substrates that bleed oil, solvents or plasticisers.
  • Non overpaintable. Use WEATHER MATE SILICONE.
  • Use as a mirror adhesive; Not recommended- Use MIRROR MATE.

Surface Preparation

The surfaces to be must be clean, dry and free from dust, grease and other contaminants.

Improve adhesion by wiping surface with EVERFLEX PVC SOLVENT CLEANER (pvc) EVERFLEX GLASS CLEANER (glass) or white spirits (painted surfaces). Priming is generally not required, although we always advise testing small areas prior to use.

Joint design should be as follows:

Minimum width: 6mm. Movement capacity will be impaired if the depth of the joint is greater than the width. For maximum movement accommodation, it is recommended that:

  1. The joint depth should be no less than 5mm
  2. Joint depth should be 5mm for joints up to 10mm wide
  3. Joints above 10mm in width should be half the width in depth up to 20mm and  minimum 10mm for wider joints

For deep joints, reduce depth by using EVERFLEX FIX AND FILL FOAM or a suitable joint backer rod.

All joints should be designed so that the seal is placed in a position which does not retain water or form a water trap.  Triangular fillets should be no less than 12mm across the face and should be finished with a flat or convex face. 


Cut the tip of the cartridge taking care not to damage the thread. Apply nozzle and cut at an angle of 45o with an opening slightly larger than the gap to be sealed. Apply using a standard sealant gun. 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. To ensure a proper bond, always smooth the sealant down with a spatula or piece of wood. An improved joint appearance can be achieved by placing masking tape to both sides of the joint, removing within 5 minutes of application.


Specific Data

Movement accommodation

+ or -25%

Skinning time:

5 - 25 mins

Cure time

1-2mm per 24 hours

Hardness Shore A




Service temperature resistance

-50°C to + 150°C

Application temperature resistance

+5°C to + 60°C

Tensile Strength (ISO8339)


Specific gravity



Uncured sealant white spirit, cured sealant EVERFLEX SILICONE EATER.

Minimum joint width


Maximum joint width   


Joint ratio

Maximum depth, 50% of joint width


10.5 linear meters as a 6mm diameter bead

Elongation at break            


Tensile Modulus at 100% Elongation


Tensile Adhesion Modulus @ 100% Elongation

0.3Mpa  (ISO 8339 (glass substrate))

Elastic Recovery