wedi building boards with a thickness of 20 mm or more are used on ceilings which are extremely uneven. Regardless of how old and dilapidated the old substrates are, you can create clean, even ceilings which offer lasting protection against moisture and insulate the room.
Step 1Use a screwdriver to punch 8 holes (around 5 per square metre) in a wedi building board.
Step 2Then apply dabs of mortar made from flexible medium-bed mortar in line with the hole markings.
Step 3Position the building board on the ceiling; tap it with a rubber hammer and align it. Then drill with a number 8 drill bit through the board and the blobs of adhesive into the ceiling behind. Support the building boards until the adhesive has cured.
Step 4Push wedi Tools dowels through the blobs of adhesive and into the pre-drilled holes but do not hammer them in until the blobs of adhesive have hardened.
Step 5The minimum dowel penetration depth in the load-bearing surface is 35 mm.
Step 6Apply wedi Tools reinforcement tape to all joints.