Silicone and other Sealants

Pro-Spec® Flexi-Seal Roof & Gutter Silicone Sealant


PRO-SPEC FLEXI-SEAL ROOF & GUTTER SILICONE SEALANT is a general purpose translucent silicone sealant suitable for metal, aluminium, galvanised iron, copper, brass, zinc, rigid PVC, glass and masonry. It is non-acid (neutral) cure, medium modulus silicone sealant. PRO-SPEC FLEXI-SEAL ROOF & GUTTER SILICONE SEALANT meets most sealing requirements of plumbing, roofing and building tradesmen.


PRO-SPEC FLEXI-SEAL ROOF & GUTTER SILICONE SEALANT can be used for sealing lap joints in roofing, flashings, ridge caps and gutters. Sealing rivet heads, prickle caps, seams and joints (galvanised iron, glazed tiles, rigid PVC, copper, brass, zinc). Seals old gutters to new, weatherproofs skylights, vents and flashings and can be used to weatherproof caravans and truck bodies.

Product Range

Product Code: 9300697116970

  • Size & Pack Type: 300g cartridge
  • Color: Clear

Technical Features

  • Excellent tradesman’s grade general purpose sealant. Will not attack zinc or zinc-containing metals or cementious surfaces. (Note: acid releasing silicone sealants attack these surfaces, which leads to poor adhesion).
  • Excellent flexibility (joint movement capability 30% total or ±15%)
  • Service temperature range –50oC to +150oC
  • Good adhesion to most building materials. (Pre-testing to confirm adhesion is advised for critical jobs and for plastics.)

Application Tips

  • Not recommended as a plug or caulk for burst pipes or rusted guttering
  • Complete painting before applying sealant. Sealant can not be successfully painted over.
  • Not suitable for aquariums or potable water containers
  • Not recommended for structural or “fin” glazing applications
  • Not suitable for seals below water or in areas of high abrasion, e.g. walkways
  • Not for use in contact with bituminous materials

Technical Details and Performance

Indicative information only, not to be used for setting specifications.


(as applied) Non-slump, soft paste, easily extruded with cartridge gun

Curing Mechanism

Rapidly develops rubber consistency by reaction with moisture from the air

Curing Rate

1mm depth per day

Skin Forming Time

5-10 minutes (depending on weather conditions)

Hardness (when cured)

Approximately 17 (Shore A, instantaneous)


Approximately 400% (ASTM D412)

Service Temperature

–40oC to +150oC

Joint Movement Capability

±15% of original joint width. When applied in properly designed joint.*


15 metres of a 5mm bead

Properly designed joint refers to the accepted concept of correct sealant dimensions, i.e. sealant depth equal to half sealant width and sealant applied over a suitable backing material which the sealant will not adhere to or which does not limit the free movement of the sealant.

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