Mapesil AC Silicone Sealant


Mapesil AC is an acetic-crosslinking silicone sealant suitable for sealing flexible fillet, shrinkage and expansion joints in ceramic, sanitary ware, glass, ceramic, anodised aluminium and painted surfaces. Ideal for internal and external ceramic floors and coatings, damp environments and swimming pools


mapei4 Mapesil AC is available in 38 colours



Mapesil AC is used for;

  • Sealing expansion joints of ± 25% expansion of the initial size
  • Forming a perfectly elastic gasket between different elements in building, mechanical engineering, ship-building, automobile manufacturing etc

Some application examples;

  • Sealing joints in wall and flooring coverings of ceramic and cement, provided they are not subject to heavy abrasion
  • Sealing joints between sinks or sanitary ware and ceramic tiles in kitchens, bathrooms and showers with co-ordinated with the grouts
  • Sealing expansion joints in swimming pools
  • Assembling compositions of glass tiles and artistic stained-glass windows
  • Sealing glazing of door and window frames
  • Sealing air ducts, water pipes
  • Sealing portholes, windows, glazed frames
  • Sealing tanks, service pipes and boilers
  • Sealing materials of different thermal exposure coefficient
  • Adhesive and sealant for general use


mapei5 Mapesil AC comes in standard 310ml cartridges



Technical Characteristics of Mapesil AC

Mapesil AC is a one component, acetic crosslinking, solvent free silicone sealant, available coloured or transparent. It is a thixotropic paste which is easily trowellable both horizontally and vertically. It crosslinks following exposure to atmospheric humidity at ambient temperatures and forms and elastic product with the following properties;

  • Excellent Durability, seals remain unchanged even after many years exposure to climatic extremes, industrial pollution, sudden temperature changes and immersion in water
  • High elasticity
  • Excellent bonding to glass, ceramic and anodised aluminium
  • Mildew resistant
  • Waterproof and permeable to vapour
  • Resistant to chemical agents
  • Flexible down to -40°C and resistant to temperatures at +180°C
  • Easily workable
  • In compliance with ISO 11600 norm, it is classified as F-25-LM
  • In compliance with numerous international standards
  • In compliance with EN 15651-1, EN 15651-2, EN 15654-3 and CE marking



  • Do not use Mapesil AC for exterior joints between ceramic tiles and light-coloured natural stone because dirt could accumulate by the joints. Use Mapesil LM
  • For sealing surfaces sensitive to acids such as limestone, use a neutral silicone sealant (e.g. Mapesil LM)
  • The use of Mapesil AC is not recommended on highly plasticised material or on bituminous surfaces because of the release of substances that reduce bonding and penetrate into the sealant, altering colour and resistance.
  • The resistance of Mapesil AC to chemical agents is generally excellent; however, due to the numerous products and working conditions to which Mapesil AC can be applied, it is always advisable to test a sample test in cases of doubt.
  • Do not use Mapesil AC to seal aquariums
  • For sealing floor joints subject to heavy traffic, use a polyurethane sealant


Application of Mapesil AC

All the surfaces to receive the sealant must be dry, solid and free from dust and loose particles, oils, grease, wax, old paint and rust. In order that the seal can carry out its function, provision must be made for it to elongate and compress freely. During application, it is therefore necessary that;

  • It adheres only to the side of the walls of the joint and not to the base of the joint
  • The joint is sized so that the estimated maximum extension is not greater than 25% of the initial width (calculated at 20°C)
  • When the width of the joint is 10mm, the thickness must always be equal to the width; for widths between 11 and 20mm the thickness must always be equal to 10mm; for widths greater than the thickness must be equal to half the width.
  • To control the depth of the joint and to prevent Mapesil AC from adhering to the base, the bottom of the joint should be filled with backer rod, a polyethylene cord.


mapei9 Estimated coverage of Mapesil AC when used in Triangular joints
mapei8 Estiamted coverage when used in end joints













Here at Sealants Direct we have bags of experience in the sealant application industry, so you can rest assured that the products we stock are of the highest quality. As a leading supplier of Mapesil AC free delivery is available on eligible orders.


Can’t find what you’re looking for? Don’t hesitate to get in touch with us today, we’re always happy to help! Simply call us on 01772 728268 for assistance and more information on Mapei Sealants.