Silicone sealants have a long and reliable track record in many settings. That’s not surprising because they produce a highly flexible and durable seal with a long life expectancy and, as they are resistant to UV light and ozone, they can be expected to last for years in the right conditions. There are two types of silicone sealant: acetoxy and neutral cure (which also have low odour levels) and while all silicone sealants have good adhesion to many common construction substrates, as a general rule of thumb acetoxy silicone sealants are suitable for non-porous surfaces, while neutral cure silicones can be used on either porous or non-porous substrates. Many people assume that any silicone sealant will adhere to any substrate – they won’t. It’s worth choosing a sealant specifically for the job you have in mind.

So what properties do our different silicone Silfix® range display and what should they each be used for?

Silfix® U7N


  • Low modulus, neutral cure, sanitary sealant
  • Contains a fungicide
  • Odourless

Uses: Sanitary

  • Sanitary sealing in kitchens and bathrooms



  • Low modulus, neutral cure
  • solvent free
  • alkoxy silicone
  • excellent adhesion

Uses: Building Envelope

  • Perimeter pointing of door and window frames.
  • Sealing curtain walling and pre-formed panels



  • Premium quality silicone: no shrinkage
  • low modulus
  • neutral cure
  • excellent primerless adhesion to glass, timber, metals, brickwork, plastics and concrete
  • Easy to apply and tool

Uses: Glazing, roofing, industrial

  • Capping and bedding of glass and insulating glass units in bead glazing systems
  • sealing joints between GRP panels and roof sheets
  • trims and flashing in roofing and cladding,
  • PVCu, aluminium, steel, timber frame and door surrounds
    industrial applications.



  • one part
  • neutral cure
  • low modulus
  • good durability in most construction joints
  • fast skinning and final cure time
  • Wide range of colours
  • Good adhesion to many building materials

Uses: Glazing, Roofing, HVAC

  • Perimeter sealing around window and door frames
  • HVAC ducting and pipework
  • General maintenance and sealing.



  • high modulus
  • acetoxy cure
  • Contains a fungicide
  • Premium quality silicone: no shrinkage
  • High gloss
  • Excellent adhesion
  • Good performance across a wide range of temperatures

Uses: glazing, industrial and domestic

  • glass/glass joints
  • shop fronts,
  • sanitary sealing in kitchens and bathrooms
  • Tiling

    In general, it is best to look for a silicone sealant specifically for the job you have in mind. If you have any questions about what’s the right sealant or sealants for you, get in touch. We will be happy to help to point you in the right direction.