The loft conversion in drywall


At least since 2009, roofs must be better insulated according to the EnEV (Energy Saving Ordinance). In this context, many homeowners consider to combine the insulation immediately with the loft conversion. The quickest and most uncomplicated way to do this is with drywall elements. Here you will receive detailed instructions for loft conversions in drywall construction.

Drywall is also ideally suited for loft conversions

Drywall is nothing more than the interior work with plasterboard and metal or wood profiles as a stand. Drywall construction has long been established in regular home interior construction, since all required properties are fully met.

  • Heat and cold insulation protection
  • soundproofing
  • Fire protection
  • Removal also in damp rooms such as bathrooms possible
  • fast, efficient and inexpensive

Cold and warm roof

What is best suited for ordinary interior work can therefore also be the optimum solution for the roof. The following instructions refer to the loft conversion in the case of a thermal roof, as most of the existing roofs, which are mainly cold roofs, are converted into warm roofs during insulation. Background is the much simpler implementation, because the roofing does not need to be removed.

Step by step instructions for the loft conversion in drywall

  • Insulating material (preferably clamping felt mats)
  • battens
  • Compensating wedges
  • steam Sparre
  • Adhesive tape for vapor barrier
  • Adhesive tape for vapor barrier for tackers
  • Adhesive in cartridge for the vapor barrier
  • Electrical installation materials
  • Plasterboard (mostly 12.5 mm)
  • Putty for drywall
  • reinforcement strips
  • Edge protectors
  • Drywall screws
  • Cutter knife
  • saw
  • miter
  • Cordless Screwdriver
  • Electric drill with whisk
  • Circular saw for electrical installations
  • stapler
  • spirit level
  • Meterstab
  • Trowel or trowel
  • Bucket for the filler
  • guide
  • silicone syringe

1. Preparatory work

The roof insulation should have a thickness between 18 and 20 cm, in order to meet the legal requirements. But not always the rafters are thick enough. Therefore, you may need to attach more battens to the rafters.

These can be attached either longitudinally, ie with the course of the rafters, or transversely to it. Quer offers you the advantage that there are no thermal bridges at the rafters. Even if the rafters are thick enough, roof battens may need to be screwed on.

Not every roof truss is really worked out exactly. To obtain a smooth, even surface, you may need to level the battens when mounting. To do this, use a guideline and place the compensating wedges according to your needs.

2. Damming the roof before the drywall

Now cut the clamping felt so that it fits exactly between the rafters. But cut the insulation mats slightly above the required dimensions, because you really have to clamp the felt seamlessly between the rafters.

3. Prepare the roof barrier for the vapor barrier

Now attach the special tape to the rafter that is suitable for the tacker. If you later attach the vapor barrier with the tacker, there is little risk that the film could break at these points and then leak.

4. Steam barrier before the drywall

Next, the vapor barrier is now attached. Always overlap the strips by about 30 cm. At the ridge ends, let the foil last about 5 to 10 cm. Now glue the overlaps with the appropriate adhesive tape.

Along the end edge of the ridge ends, use the silicone syringe and sealant to pull an approx. 0.8 cm bead after you have turned the foil inwards. Afterwards, fold back the vapor barrier. The overhanging film can be cut off after drying.

Finally you glue roof penetrations, roof hatches and dormers. For this you can use the vapor barrier tape or special sleeves. The vapor barrier really needs to be absolutely tight.

5. Perform the loft conversion in drywall

Now come the plasterboard. They are screwed onto the rafters or battens. Laterally, the gypsum boards have depressions that form a joint. If you had to cut one of these joint areas, chamfer the cut edge before attaching, so that you get a joint again.

6. Fill and sand the plasterboard

Once all gypsum boards have been fixed, the most complex part will start with filling and sanding. Depending on further loft conversion (painting, wallpapering, tiling, painting, etc.) you must fill the joints in low to very high quality and grind. Accordingly, you may need to repeat the process several times.

At large joints and at the expansion joints you can use reinforcements. This reduces the risk that the grout might break later. At particularly endangered edges you can attach edge protection strips, which are filled in.

Tips & Tricks

With a canopy, you can use the crossbeams to attach the plasterboard to the ceiling.

Please note that house ventilation must be ensured for the conversion or insulation to the warm roof.

Depending on the loft conversion, you can also make the drywall so that the roof truss remains open as a visible roof chair.


Video Board: Boarding the walls | Loft Conversion Project 6.0