Gypsum Plaster


Introduction:

This standard operating procedure enumerates the scope of Gypsum Plaster work to be executed in Tower area as specified in the approved drawings and at places when instructed by the Tower-in-charge.


Responsibility:

The respective Tower-in-charge is responsible to execute the work as per procedure.

Safety & protection:

Working space to be clear of debris so that easy access is ensured
Scaffolding to be checked for the load carrying capacity and ensure no overloading.

Lifting, manual transporting of materials have to be carried out by workers who are properly trained. Otherwise this may cause serious injuries to workers.

Throwing of debris from height strictly prohibited.

PPEs should be used properly.
 

Preparatory Works: 

All the nails, binding wire, masking tapes and wooden piece shall be removed from concrete surface.

All the dust, oil spots, and green algae, if any shall be cleaned from concrete and Blockwork surface with the help of wire brush.

Proper scaffolding shall be provided to allow easy approach to every part of the work. 

In no case, holes in Blockwork should be done for supporting scaffolding.

At place of work where sufficient natural daylight is not available, artificial light shall be made available.

Level pads of size 1 x 1 shall be made on the walls. 

Level pads shall also be checked for vertical alignment with the help of plumb bob, for right angle with the help of try square and for diagonal dimension of room with the help of tape.

Fiber mesh should be fixed on all concrete and blockwork joints (except base course joint). 

In case of level differences in adjoining surfaces, the same shall be made up before fixing of chicken mesh.

Ensure Concrete surface roughened for proper bonding.

All electrical chases shall be filled with cement mortar and properly rendered with non-shrink grout and application of fiber mesh over it. 

Curing should be done for 7 days before starting any type of plaster.

All the conduit drops shall be checked and concealed with plaster, if any visible in opening area.

All the ceiling points and wall points shall be checked for level and dimensions as per drawing or as per clients requirement if any. 

Ensure electrical boxes and light point boxes are in line with finish face of plaster.

Gypsum plaster thickness shall be restricted to 10 - 15 mm for walls and 6 to 8 mm for ceiling. 

If because of undulations the final thickness is expected to be more than 15 mm, back coat is recommended before applying Gypsum Plaster.

Back coat of 6 to 10 mm thick (cement sand mortar) shall be applied on Blockwork. 

Curing of Back coat shall be done for 7 days before starting gypsum work. 

Back coat shall be in rich 1:4 cement mortar.

After applying Back coat (wherever required if any) or after checking the thickness of gypsum plaster, Level strips of Gypsum shall be made through full height of wall and shall be checked for vertical alignment with the help of plumb bob, for right angle with the help of right angle and for diagonal dimension of room with the help of tape.

Level strips of Gypsum 6 wide shall be made on ceiling at wall  ceiling Junction and it should be checked for right angle.


Work Method: 

Gypsum plaster shall be applied only after back coat dries off completely.

Mixing of gypsum should be done in clean buckets/ trays as per proportions specified by manufacturer.

Old left out mix should not be used with new mix at any time.

The Gypsum shall be dashed against the prepared surface. 

The dashing of the coat shall be done using a strong whipping motion at right angles to the face of the wall.

The coat shall be led hard and tight forcing it to surface depressions to obtain a permanent bond and finished to smooth surface.

The finishing is made with the help of trowel and Metal straight edge.

Surface should be smooth after application and should be check for plumbs, right angles.

No chasing shall be done after application of final coat on walls /ceilings.

Electric switch boxes, fan boxes etc. shall be cleaned immediately after completion of plaster.

Floor should be cleaned on completion of days work.


Team 
CBEC India