Jointing and sanding


Cleaning joints

Note: Water is not suitable for binding dust as it increases the likelihood of crack formation.

1. Clean the joints of dust deposits in the joints after finishing attachment of the boards with a dry brush.


2. Prime with Knauf Tiefengrund primer if necessary (e.g. in case of high dust formation during board application).


Filling joints

Note: Use the cartridge with nozzle together with a pouch gun and a cartridge gun.

1. Cut the plastic nozzle to suit the joint width and attach it to the cartridge outlet.
2. Fill the joints with Uniflott.


Jointing and sanding

1. Chip off the excessive material after initial setting of the filing compound with a Cleaneo spatula and leave approx. 1 to 2 mm of protruding material in place.

2. Subsequently skim filled joints cleanly with a screw handle spatula before the filler has hardened so that a string of material is formed.
3. Fill the screw heads also with a filling material, preferably using a Cleaneo trowel.


4. Sand off excess filler compound smoothly and evenly after hardening.

Surface treatment

Before application of a coating the board surfaces must be free of dust.

Note: Use a short pile lambskin roller to ensure that paint does not penetrate into the perforations and affect the acoustical performance of the fleece.

Note: Gypsum board surfaces that have constantly been exposed to light without any protection can cause yellowing after coating. Recommendation: A trial coat is recommended that will extend across several boards including all joints. Yellowing can, however, be successfully avoided only by using a special primer.

Knauf tools

  • Pouch gun 
  • Cartridge with nozzle 
  • Screw handle spatula 
  • Cleaneo trowel

Sanding tools
  • Abranet® hand sander with suction function 
  • Abranet® sanding mesh P80 
  • Abranet® sanding mesh P120
  • Abranet® sanding mesh P180 
  • Suction hose for Abranet® hand sander