Anyone who has ever lived in an old house with doors without seals knows that this can be unpleasant. Apart from the fact that cold air trains and smells can get through, you understand almost every word that is spoken in the room when you are standing at the door. This is also what it is all about when a seal is mounted. For example, a fire-proof door must be smoke-proof. This not only brings something in case of fire, but also does not allow any other draught.

 

This effect can also be easily checked on windows. Every wing all around has a seal that is glued together or welded on miter in every corner. This has been done for years. If you close the window sash, it immediately becomes quieter.

 

Today, windows and doors are very technical products that must meet clearly predefined requirements. For example, a certain thermal insulation value is specified for a front door, and even a room door must reach a sound insulation value according to the specification. Every decibel is fought for. This has to do with the construction of the door leaf and the frame, the connection to the existing wall and the seals. And every small gap makes that value worse again.

 

It is astonishing that the seals are also incorrectly mounted on many completely new doors. In the corners they very often run bluntly together, which creates an opening through the profile shape. They also like to have some air because they were pulled during assembly. Later, they contracted again, causing the sealing corners to open. However, if the seal is not completely sealed, the decibels obtained from the door construction are immediately given away again.

 

Felix Wirz is a development engineer at RWD Schlatter AG in Roggwil TG. He knows that inner seals – i.e. those that come to the door leaf – must be welded or glued pre-assembled or glued, just like those of the windows. The outer seals that come to the frame must converge in the corners on miter, without the joints being able to rise later.

 

The outer seals should be cut with a little overlength, so that they cannot retreat too far when cooling down. When inserting, the ends are first pressed into the groove, whereby the grooves must be closed well. Then press the center of the seal, then press the middle of the two pieces and from there the remaining seal in such a way that it cannot warp in length.

 

In the case of the inner seals for the door leaf, the corners and the sealing ends are first pressed into the groove, then the same procedure follows as with the outer seals.

 

Poesia Holding AG in Unterkulm AG manufactures seals and manufactures the inner seals for the door and window sashes with various special equipment. These are glued or, if possible, welded. The latter is something for professionals in this field.

 

However, Stefan Hunziker, head of the construction products division in this company, points out that it is quite possible to cut the seal yourself with a miter scissors and then glue the miter with second glue, for example. To do this, it must be ensured in advance that this adhesive is suitable for the sealing material. However, gluing requires skill and time, which is why it is worth ordering ready-made seals. In time, this should not be a problem, as the seal type and the mass must already be known during the execution planning of the door.