Carry out roof extensions

Since 2011, the Energy Saving Ordinance, EnEV, prescribes the insulation of the roof. Depending on use and roof type different insulation can be made. A roof insulation often leads to further roof extensions. Here is a guide for all roof extensions available.

Connect the roof insulation with loft extensions

Often homeowners decide when implementing the EnEV for a roof insulation, as the loft extensions additional living space is created. In addition, funding can be requested. But there are two options for dams open.

  • roof insulation
  • Ceiling insulation (between residential and attic storey)

The roof insulation is often reason for further roof extensions

According to the Energy Saving Ordinance of 2011, homeowners are obliged to insulate their roof. If the roof space is no longer used, a ceiling insulation between the roof and underlying living floor is sufficient. In many cases, however, homeowners are considering taking the opportunity to undertake major loft conversions.

  • roof insulation
  • Roof extensions with plasterboard

Then the attic can also be used as an extended living space. Especially with warm roofs this is recommended.

Step-by-step instructions for carrying out loft conversions

  • Thermal insulation (clamping felt)
  • possibly roof battens
  • Tackerdichtfolie
  • vapor barrier
  • Adhesive tape for vapor barrier
  • Sealant (cartridge) for vapor barrier
  • Sealing sleeves for roof penetrations
  • Plasterboard
  • Drywall screws
  • Electrical installation materials
  • Putty for drywall
  • Sandpaper in different grain sizes
  • Saw or Stainley knife
  • Cordless Screwdriver
  • drilling machine
  • Circular saw for drilling machine
  • silicone syringe
  • trowel
  • Container for putty
  • Building easel or construction manager
  • Meterstab
  • spirit level

1. Preparatory work

In the case of roof insulation as a partial measure in loft conversions, you can proceed in different ways: interim or rafter insulation or a combination thereof. This is necessary if the required strength of the rafters is not sufficient for intermediate rafter insulation. In order for the insulation to comply with the EnEV, you must achieve an insulation thickness between 18 cm and 20 cm.

So you first have to measure the rafter thickness and if necessary purchase roof battens. Now you can proceed differently again. Either attach the battens along the rafters. Or you attach it across and then create a second insulation. The second, transverse insulation has the advantage that you insulate over the rafters. The electrical installation can also be performed better.

2. The roof insulation

Cut the nipping felt according to the intermediate dimensions from one spar to the next. Cut the insulation mats over the measure so that you can clamp the felt mats without joints between the rafters. Proceed in the same way if you have attached an additional cross battens for optimal insulation.

3. Seal the insulation

On the rafters or roof battens you now attach the special tacking tape. If you fix your vapor barrier later, you reduce the risk of cracks and leaks.

Now comes the vapor barrier. Attach the foil from one to the other ridge end. Leave the foil at the ridge ends by 5 to 10 cm. Overlap the sheets to each other by about 30 cm.

After the vapor barrier is tacked, glue the overlaps. Fold the outer protrusions of the film on the ridge ends and spray the sealant in a caterpillar about 0.8 cm thick. Now beat the foil back. After drying, cut off the supernatants.

4. Attach the plasterboard

Now start to fix the gypsum boards on the rafters or roof battens. Screw in the screws at a distance of between 50 and 100 cm as required, and then countersunk. On the outside, pay attention to compliance with distance and expansion joints. Use the circular hole saw to drill the holes for electrical boxes.

5. Fill in and sand the plasterboard

Now fill the joints and screw holes with putty. In large joints, insert a reinforcement. After curing, you can grind the putty. Depending on the other loft extensions on the walls (wallpaper, wall paint, lacquer, metal wallpaper), you have to spatulate and sand the plasterboard several times.

Tips & Tricks

The thermal roof is the new construction standard. Compared to the cold roof, the warm roof is not ventilated. Thus, it does not have to be open to diffusion, but requires a corresponding device for the deduction of the house moisture. Since the cold roof has to be insulated against diffusion, you can only use this manual for warm roofs. Otherwise, it quickly leads to condensation and, as a result, to mold and sponges.

The house journal also offers numerous articles on [sanding plasterboard]. The differences between the different quality levels are also covered.

Video Board: timber roof on a single storey extension