For the manufacture of slopes, moisture -resistant drywall is used. First you need to knock down a layer of old plaster from old slopes. If you plan to glue drywall, you need to treat the surface of the slopes with a primer. After the primer dries, a thin film will appear at the site of its application: it means that you can continue to work on the installation of slopes. Draw on the window frame two vertical and one horizontal lines at the site of future slopes. Scrill over to the frame of the P-shaped, plastic bar, which should be located so that its edge lies exactly along the drawn line.
