Plaster on masonry around chimney flues or drain pipes.

Structure type

Brick masonry with walled-in chimney flues or drain pipes.

Detail

Application of interior or exterior plaster.

Application cycle

1. Scratch coat over the flue or the infilled drain chase with RALLK Muro K SRG bonding mortar, applied by hand or by plastering machine.
2. Machine-applied plaster RALLK Muro K PM, plaster made with RALLK Muro K M5 plastering mortar, or alternatively standard plaster, class CS I – CS III according to UNI EN 998-1.
3. Skim coat of RALLK K OttO or alternatively RALLK Rasante K with embedded 150 g/m² glass fiber mesh, laid from top to bottom with the vertical strips overlapping by at least 10 cm. The mesh must cover the whole surface or, alternatively, straddle the concrete load-bearing element, extending at least 30 cm onto the brickwork on either side of the columns and over more than one course of bricks at the ring beam. Meshing the whole facade is recommended for porous brick infill walls.
4. Finish with a finishing coat, RALLK Marmo K powder mineral finish or another mineral finish, acrylic, siloxane, lime or silicate paste finish, or lime, siloxane, acrylic or silicate paint, as set out in the specifications.

Additional information

1. Based on current site experience, a reinforced skim coat on fully cured plaster is an effective way to prevent hairline cracks in the plaster caused, in the medium and long term, by minor settlement, an uneven substrate, vibrations or thermal expansion.
2. See the individual product data sheets for application methods and precautions.