Filler Fermacell - that's right

Just like plasterboard, Fermacell construction boards must be filled after assembly. Where the differences lie between Fermacell and Rigips, and how to do the filling properly, read in detail in this post.

Fermacell or Rigips

The classic GK-plate (Rigips) consists of plasterboard, while the manufacturer Fermacell alone produces gypsum fiber boards. For the manufacturer Rigips this type of plate is called "Rigidur".

Gypsum fiber boards are made of paper fibers, gypsum and water. All materials are pressed together to form a very stable and durable plate of gypsum fiber material.

The lighter Rigips plates (GK plates) consist only of the gypsum core and a cardboard casing. They are also cheaper than the higher quality Fermacell gypsum fiber products, but their stability is at least as good for interior design.

Suitable filler for Fermacell

For Fermacell, it is possible to use all leveling compounds that a manufacturer considers suitable for filling gypsum plasterboard or Gypsum plasterboard identifies.

It is not mandatory to use a special Fermacell filler. These products are usually more expensive in the trade, but consist of the same ingredients as fillers for GK boards. Not to be used only:

  • plaster
  • all fast-curing putties
  • all leveling compounds that are not specifically suitable for filling plasterboard

Joint Tape

A reinforcement of the joints is useful for both Rigips and Fermacell. Such cover strips are usually made of special paper materials or a fiberglass material.

They increase the stability of the joint and thus avoid later cracks or cracks in the joint area. Fugendeckstreifen are inserted after the first spatula. Then they have to be completely filled again (you can not see them afterwards).

Even professional fiber strips are not expensive. Usually you have to pay around 0.10 EUR per meter.

Filling Fermacell properly - step by step

  • suitable filler
  • Primer (depth reason)
  • acrylic
  • Broad spatula, smoothing spatula, narrow spatula
  • gypsum cup
  • possibly a drill and a stirrer
  • Sanding block and fine sandpaper

1. Preparation

Coat the edges of the Fermacell sheets with a primer and allow to dry in accordance with the manufacturer's instructions. Only after drying can be started with the putty work.

Mix the filler. Only stir as much as you can process in the stated processing time (manufacturer's information on the package). In case of doubt a little less, as hardened residues in the reservoir are usually very annoying and can affect the quality of the filler.

2. Smooth the joints, first pass

Fill in the horizontal joints first. To do so, paint the grout with a broad spatula across the joint and push it into the joint. After that, the vertical joints from the bottom up plastered.

3. Fill joints, second pass

After the putty has dried, insert the Fugendckstreifen and once again carefully over-level.

4. Fill the screw holes

Fill the screw holes crosswise with putty and smooth. There must be no more depressions.

5. Third putty pass

For a ready-made wall may need to be filled a third time. After the last filling and drying of the filler, carefully sand the plasterboard.

Tips & Tricks

On outside corners and edges you should definitely install an edge protection. This can be edge protection strips or a flexible edge protection. The sensitive edges are thus protected and the subsequent result is visually significantly cleaner than without edge protection.

Video Board: A guide to fine surface filling.