Window sealing: That‘s how it‘s done!

Drafts around win­dows not only affect your com­fort at home. They also cause heat loss and can cost you a lot of money in energy bills. Our expert explains how to find leaks and how to close small cracks and joints single-handedly. How­ever, in the case of cav­it­ies in the trans­ition area between win­dow and wall and on the facade, it is neces­sary to con­sult an expert. To pre­vent drafts from enter­ing your home, it is best to invest in prop­er insu­la­tion right from the start, prefer­ably with healthy build­ing mater­i­als that are recog­niz­able by the EC1 seal.

Tip 1: Detect thermal bridges around windows

First of all, scan the interi­or walls with your hands. Any cold spots you can feel indic­ate thermal bridges. With a burn­ing candle (be care­ful with cur­tains!) you can quickly determ­ine the dir­ec­tion of the draft. Altern­at­ively, you can clamp a piece of paper between win­dow frame and win­dow. Close the win­dow. If the paper can now be pulled out without effort, the seal is no longer intact. Thermal ima­ging cam­er­as provide the most reli­able inform­a­tion about the loc­a­tion of leaks.

Tip 2: Eliminate leaks

Joints and cracks between win­dow frame and sash can be closed very well with self-adhes­ive seal­ing tapes. Altern­at­ively, rub­ber seal­ing strips can be used to stop drafts. To reduce heat trans­fer via the win­dow panes, they can be covered with an insu­la­tion film. Spaces between win­dow pane and frame as well as con­nec­tion joints can be filled with inject­able insu­la­tion mater­i­als such as acryl­ic and sil­ic­one seal­ants. In the case of cav­it­ies between masonry and win­dow frame and also around win­dowsills and roller shut­ter boxes, the spe­cial­ist must be called in. It is import­ant to seal the win­dows both to the out­side and to the inside, because the fol­low­ing prin­ciple applies: Inside tight­er than out­side. This helps to pre­vent mold and mois­ture dam­age.