Installing windowsill needs good preparation


Who wants to assemble a windowsill, has by easy preparation in the normal case easy game. The assembly in the interior is much less expensive than the counterpart in the outdoor area. What is important is a precisely cut and suitable plate - whether made of wood, natural stone or metal.

Practical mounting foam

Mounting foam is the crucial material that simplifies mounting a sill. Except for massive natural stone window sills in block form, the mounting foam can be used for all types of window sills both inside and outside. He first serves as a liquid placement pad and developed by dehydration adhesive power. If a window sill made of plastic or wood is mounted inside, often even two-sided adhesive tape is sufficient for attachment.

The mounting takes place with a tailor-made window sill, which is usually the case with stone when buying. If so-called standard dimensions are available, it is advisable to check whether the masonry work has been carried out with corresponding precision. Subsequent adaptation is only possible with the corresponding special tools such as stone or metal saws and grinding machines, which are not available in a conventional private household.

Installation of a window sill made of different materials

  • cement
  • water
  • connection profile
  • Putz connections
  • Mounting foam or glue or
  • Double-sided adhesive tape
  • Insulating materials and insulating foils for cold and sound
  • grout
  • Wooden wedges or blocks
  • spirit level
  • Folding rule or tape measure
  • rubber hammer

1. wood inside

Cut out the measured and marked board and place it either on a thin layer of mounting foam, glue or fix it with double sided tape

2nd stone inside

Measure out the parapet and the wall cut-outs and let the plate be sawed in the specialized trade. Always add a measuring tolerance in favor of possibly wider joints. Use mounting foam.

3rd stone outside

Add the trimmed plate with the necessary inclination of about ten percent to its depth. If necessary, support the precise position with wooden wedges or blocks.

4. Alu outside

Before mounting, install a sound-absorbing foil or anti-drumming tape under the aluminum bench. Pay attention to the inclination and an undamaged drip edge.

Tips & Tricks

For window sills of all materials, attention must be paid to the seal to the window frame with a suitable connection profile. For plastic, aluminum and wood, lateral plaster connections must be fastened before installation.


Video Board: Installing Custom Window Sills