Isolate a roof expertly

The roof is probably the biggest weak point of a house, which concerns the loss of energy. In addition, there are constantly tightening energy laws. Accordingly important is the insulation of the roof. Below you will not only get a detailed guide to insulating your roof, we also offer you valuable tips and what to keep in mind.

The roof insulation makes sense and saves money

Of course, in the winter you have already noticed that there is a closed layer of snow on roofs, while the white splendor on other roofs has long since melted away. This does not always mean a poor insulation, because depending on how you use your roof space, either the ceiling to the roof (the loft space as storage) or the roof itself (in a loft conversion) is isolated.

Before insulating: which roof do you want to insulate?

However, if an attic is developed and the snow has melted, the insulation is not good. If you want to insulate such a roof, you must first determine your roof construction.

  • cold roof
  • warm roof

Cold roofs are roofs, as they were covered for a long time. So without additional insulation. Warm roofs, however, are lined inside at least with a diffusion-open insulating film. If your roof is a cold roof, you must first inquire about the legal requirements of the energy laws and prepare your roof accordingly.

Techniques of interior insulation of roofs

Otherwise, you can start with the inner insulation of your roof. Again, two different techniques are used, which are also used in combination.

  • Rafter insulation
  • Aufsparrenisolierung

Again, in addition to your needs, it is the energy laws that determine whether inter-rack isolation is sufficient or supplemented by a rack insulation. Therefore, both installation techniques take into account the installation instructions.

Step by step guide to insulating a roof

  • insulation
  • Insulating adhesive in cartridge
  • special insulating tape
  • special insulating adhesive in tube
  • Roof battens as needed
  • Drywall screws
  • vapor barrier
  • Sound insulation sealing tape
  • Cutter or insulation knife
  • Cordless Screwdriver
  • hammer
  • spirit level
  • stapler
  • Yardstick or tape measure
  • silicone syringe

1. Preparatory work

Before you start isolating yourself, you need to determine the rafter depth. Because according to the energy laws, the interior insulation must have a minimum depth. If this is not enough, you can continue the further insulation with an additional insulation on the rafters. Then, then, the need of the roof battens.

2. Install the insulation

The insulation is insulating mats, which can consist of different materials (glass, stone, tree or hemp wool). Common felt mats have a line marker. That's always the inside, so turned to the room.

Now cut the insulation mats to measure. These are also referred to as felt clamping mats because they are clamped between the rafters. Cut the mats about 1.5 to 2 cm wider than the distance between the rafters. The mats must not leave any joints when they are pinched.

3. Install the vapor barrier

For the rafters you can use a special sound insulation and sealing tape. If you later tackle the vapor barrier film, you reduce the risk of the film tearing. In addition, the area is sealed against moisture, so you have no weaknesses here.

The vapor barrier foil will now apply you across the rafters. Allow the film to overlap longitudinally at least 10 cm above the previously installed vapor barrier. At the front and the end, let the foil also last 10 to 15 cm.

The longitudinal overlaps are now glued with a special adhesive tape. Thus, the overlaps are sealed airtight. Penetrations around it, such as antenna or satellite dish stands, also apply a special adhesive tape to make the vapor barrier airtight.

At the (mostly) First connections you had to let the foil out. Now fold it back towards insulation and spray the cartridge sealant in a thick bead (about 0.7 to 1 cm in diameter) along the corner edges. Then push the foil into the sealant. After complete drying, you can cut off the supernatant.

4. Install additional rafter insulation

If you need additional insulation, now fix the roof battens across the rafters. Now that you have already installed the vapor barrier on the intermediate buffering insulation, all you have to do is assemble the cut-out felt mats. In addition, you can also lay your electrical installation here. Later, you can continue the loft conversion by simply screwing plasterboard to the roof battens.

Tips & Tricks

In particular, if your roof is not a modern, insulated, warm roof, you need to bring in a high level of expertise. The insulation of a cold roof depends on many factors. If you do not proceed correctly, condensation can collect in the insulation, mold and sponges are then only a matter of time.

Of course, we also offer numerous articles in the house journal about the interior design, so you will also find descriptions and instructions for [interior work with plasterboard].

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