The double-sided POLYFORM window sill is used when installing both external and internal window sills. POLYFORM sill heads are precisely adapted to specific window systems. The POLYFORM window sill is suitable for aluminum, PVC, wooden joinery, as well as other materials.
The proposed connection with the window frame ensures continuity of thermal insulation, protects the joint between the window and the wall against air infiltration and rainwater leakage, and eliminates thermal bridges.
The use of a double-sided POLYFORM window sill significantly facilitates window opening finishing works.
XPS 300 material – extruded polystyrene from HOCH and SYNTHOS
Equipped with a sill head matched to a specific window system
Additional sealing of the connection with the window frame using expanding tape
Possibility of using a PVC mounting strip for anchoring to the external wall
Standard total heights: 55 mm, 60 mm, 65 mm, 70 mm
Element length: 1180 mm
Width: 380 mm
Possibility of custom configuration of external dimensions and finishing details
Compressive strength at 10% deformation: 300 kPa (30 tons/m²)
Thermal conductivity coefficient: 0.036 W/mK
Reaction to fire: Class E
Water absorption during long-term immersion WL(T): below 0.7%
Wind resistance: Class C5 (PN-EN 12211)
Water tightness: Class 9A (PN-EN 1027)
Air permeability: Class 4 (PN-EN 1026)
Warm installation, also known as sealed or layered installation, is currently the most advanced window installation solution. The installation consists of three layers:
Internal layer – protects against water vapor penetration; made of a vapor-tight window tape
Middle layer – thermal insulation; the double-sided POLYFORM thermal window sill offered by us tightly fills the space between the wall and the window frame
External layer – a waterproof tape protecting against moisture from atmospheric precipitation
The POLYFORM double-sided thermal window sill, commonly known on the market as a warm window sill, is one of the key elements of warm window installation. It is manufactured from XPS 300 extruded polystyrene, characterized by excellent thermal insulation properties and high compressive strength.
Installing windows in external walls often leads to the formation of thermal bridges. The use of POLYFORM thermal window sills eliminates the negative effects of installation errors. At the same time, it prevents heat loss in the window sill zone, significantly improving the building’s overall energy balance.
The POLYFORM thermal window sill also eliminates drafts and air leakage while reducing noise. It facilitates the installation of both internal and external window sills, improving the overall aesthetics of the finish.
All POLYFORM window sills are manufactured for specific window systems. For additional sealing at the connection with the window frame, the POLYFORM sill is equipped with expanding tape.
It is also possible to use a PVC adapter strip to anchor the sill to the external wall.
POLYFORM window sills are produced in 118 cm sections. Joining multiple sections is airtight due to the very smooth contact surfaces. Additionally, the joints can be secured with adhesive designed for XPS boards.