Customised thermal insulation and substructure for window sills

High compression strength combined with very low thermal conductivity

ISO-TOP WINDOW SILL FORMS are insulating profiles made from XPS polystyrene; this has very high compressive strength and was specially developed as thermal insulation for aluminium lower external window sills. This is always a critical area with respect to heat retention.

The ISO-TOP WINDOW SILL FORMS do not simply offer excellent thermal insulation. They also provide a compression-resistant substructure for window sills made from aluminium or mineral materials. The window sill forms have a positive effect on the temperature factor fRsi, they increase the surface temperature in the area of the inner window sill and thus reduce the risk of moisture and mold.

Product benefits
  • very high compression strength
  • very low thermal conductivity
  • manufactured to size and shape to suit individual, project-specific requirements
  • reduction of structure-related thermal bridges
  • complies with the requirements of the Building Energy Act (EnEV was vaild 31.10.20) and the recommendations of the RAL “installation guide”
  • optimises the temperature factor fRSi
  • ideal for sealing the lower connection in combination with MS Polymer
  • simple adjustment of length using standard mitre saws
  • excellent for building renovations to reduce energy consumption
  • can be combined with the system products of the ISO3-WINDOW SEALING SYSTEM
  • 10 Year Function Warranty*

* On the conditions of the manufacturer (available on request).

Application Areas

Reduction of constructive thermal bridges in the window sill connection area

ISO-TOP WINDOW SILL FORMS are installed immediately beneath window sills. They help to avoid thermal bridges and optimise the thermal insulation in the area connecting with the window sill in residential buildings, single-family homes, nearly zero energy buildings and passive houses.

ISO-TOP WINDOW SILL FORMS can also act as the second sealing level if they are glued all round to the wall and window profile in combination with an ISO-TOP FACADE SEAL.