How strong is drywall

Filling walls: large areas, corners and edges

Drywall construction is a great thing: with a stud frame made of wood or metal and plasterboard (e.g. from Knauf, Rigips or Fermacell), meter-long walls can be erected in no time and without the hassle of mixing mortar and long drying times before further processing. Because the metal-plaster combination is considered to be a "light partition wall", any do-it-yourselfer can place it freely in the room without costly static calculations. Here's how to do it.

Fill plasterboard

As easy and quick as the erection of the walls is, for the followingFilling the joints, careful and detailed preparation is necessary so that the result is good. From a technical point of view, the many individual plasterboard panels only become a wall through the hardened grout, which then moves as a whole due to the constant changes in the room climate.

The Grout balances the tensile and compressive forces that occur within certain limits; it is usually plastic and fiber-treated for this purpose. How strong the dynamics will be in such a wall also depends to a large extent on the material of the stud frame. Anyone who chooses slats from the hardware store for this must expect more movement and a higher tendency to crack. Better, and ultimately not more expensive, are the metal profiles that are available for every application.

tip: Normal sandpaper, especially if it is cheap, clogs up with the fine plaster dust of the dried grout in seconds. Abrasive meshes are better here (also from the hardware store): They have a greater removal rate and also keep them much longer. Use a 100 grille for sanding.

The right filler for drywall

The task of the filler is to provide a perfect surface with good workability. The technical requirements for the compound for static load-bearing capacity on the one hand and for a smooth, fine-pored surface on the other hand differ so widely that manufacturers such as Knauf have two different but complementary leveling compounds in their range. For example, "Uniflott" is for mixing and the first rough work step, "Uniflott Finish" is ready-to-use and is used for fine-tuning.

By the way: Read here how to install a loudspeaker in the drywall.

This means that both of the tasks mentioned must be carried out in two steps. Depending on the room climate, the drying time between these filling passes is a good hour. If in doubt, you should rather wait longer for that Wall putty doesn't end in drama.

Filling drywall walls: two-step instructions

If you have to fill large areas, the first filler does not have to be done too carefully. First of all, it is more important that all joints are completely filled. You can't get a really good surface on first gear anyway. The second trowel with the ready-to-use "finish" compound is more suitable for this. For that you use a straightener, not a trowel.

Furthermore, after the first leveling and the necessary drying time, the unavoidable protrusions of the leveling compound should not be completely sanded off, but should first be roughly knocked off with a trowel. Here, too, the trowel is guided diagonally to the course of the joint so as not to scratch any grooves in the joints.

When working a joint tape into the fresh filler, you always start at the top of the vertical joints and work your way down. The horizontal joints are started on the side where the trowel is used - left-handed people on the left, right-handed people on the right. This way you can get the gently pulling movement of the trowel easier.

Fill large areas

You must bevel the short panel edges before screwing them to the stud frame. This is the only way that the joint compound will later have a sufficiently large and deep adhesive surface. Then treat the bevelled edges with the plaster core with the deep primer.

Then pull the mixed grout generously over the joints with the trowel or trowel. Hold the tool slightly diagonally so that it does not slip into the joints when you pull it off.

Here and there you will come across a drywall screw that is not fully countersunk. Tighten them with a screwdriver. Attention: Do not turn the screw completely through the cardboard jacket!

After the drying time, sand the leveled surface with the sanding mesh. The second filling process follows.

To make your wall a success, you will find sanding sheets at the best price here:

Fill corners and edges

If the larger areas of the Drywall are filled, the fine work follows. The corners, edges and transitions of a room in particular require a lot of attention.

With an adhesive strip (for example "Trenn-Fix"), which is stuck next to the plasterboard on the plaster of the adjacent wall, you prevent direct contact of the filler with the masonry. The strip must be glued over the entire height.

The filler is then used to work into the joint up to this separating strip. This is followed by intermediate sanding after about an hour and the second troweling with the ready-to-use compound.

Once everything has been filled and dried, cut off the protruding part of the adhesive strip with the cutter.

The joint between the lightweight construction wall and the adjoining wall can also simply be closed with an acrylic compound from the cartridge. Here the permanently elastic mass must adhere to the plasterboard and the masonry ("two-flank adhesion") so that it can withstand the unavoidable movements of the components without cracking.

Danger: No silicone should be used, because it cannot be covered with wall paint or plaster afterwards!

A thin metal corner protection strip is incorporated into the outer corners of the planked drywall. Firstly, this forms a clean and straight edge and secondly, it prevents the putty, which is brittle when dry, from breaking off.

The bar is fixed with some staples that are placed alternately in both legs. The bar must be as tight as possible. A spirit level is used to carefully check whether it is perpendicular. They are allowed to spring back about 2 to 3 mm on the floor and ceiling to avoid direct contact.

After the first coarse filling and intermediate sanding, the fine filling is done. With a large smoother, the ready-to-use compound can be worked better up to the corner protection strip and pulled out to zero in the area. Any dried-up protrusions on the metal edge can easily be pushed off later.

The joint between the planked wall and the screed should definitely be left open. Here, too, there must be no direct contact in order to prevent sound transmission from the drywall to the screed and thus into the building.

Ideally, 2 to 3 mm (inch rule thickness) space was left when screwing the panels together. The joint will later be completely covered by the floor covering and the skirting board.

If you have followed all of these steps correctly and with certainty, you should not have any problems with the filled walls.

For further reading: Overview of types and areas of application for various fillers!