METHODOLOGY / PROCEDURE OF GYPSUM PLASTER

WORK METHODOLOGY / PROCEDURE OF GYPSUM PLASTER

Ø  Predecessor activities clearance shall be taken to start the gypsum work.

Ø  Before taking up Gypsum plastering work it shall be confirmed whether concealed electrical and plumbing lines are completed and tested.

Ø  The surface to be plastered shall be chipped off any projection, brushed off for dirt and efflorescence and hacked off (for RCC only).

Ø  All substrate defects shall be repaired up before gypsum plastering. 

Ø  All Tie patti and tie rod holes must be filled through and through with approved filler materials.

Ø  Approved Bonding agent shall be applied on RCC surface before gypsum plastering where ever required.

Ø  Approved Fiber Chicken mesh shall be provided at the joint of masonry work and RCC structure.

Ø  Leveling pad shall be provided to maintain the thickness of the gypsum plaster.

Ø  A grid of level strips shall be made by filling of gypsum material by putting aluminium box plate.

Ø  The surface shall be well soaked and touch dry before starting plaster work to avoid absorption of water present in the mixed gypsum by the dry masonry.

Ø  Level pads/strips of size not less than 2’’x 2’’ shall be made on walls and if required on ceiling also to serve as finished reference level surface.

Ø  The distance between level pads shall not exceed 1mt in any direction so that their surface alignment can be checked with the help of aluminum straight edge.

Ø  Level pads shall also 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

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

Ø  Glass fiber mesh shall be fixed at the joints of block masonry and concrete and fibre mesh shall be of 90 GSM or as recommended by client.

Ø  Surface preparation such as all the nails, binding wires, concrete projections and wooden pieces shall be removed from concrete surface and brick masonry

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

Ø  It is recommended that all concrete surfaces where plaster is to be applied shall be pre-applied with bonding agent.

Ø  Bonding agents shall be applied as per instructions of manufacturer.

Ø  Gypsum shall be applied on bonding agent applied surface within 2 to 10 days of application of bonding agent.

Ø  All electrical chases shall be properly rendered with non-strink grout and application of chicken / fiber mesh over it and cured properly for 4 days before starting any type of plaster.

Ø  All the conduit drops shall be properly checked and concealed with plaster.

Ø  All the ceiling points shall be checked for level and dimensions as per drawing or as per client’s requirement if any.

Ø  It shall be ensured that all electrical boxes are protected with plastic sheet packing before

Ø  Fixed doors/ windows frames shall be protected before start of plastering.

Ø  It shall be ensured that all plumbing points are in proper location, line and level as per drawing.

Ø  All plumbing chases shall be properly rendered with non-shrink grout and application of chicken / fiber mesh over it and cured properly for 4 days.

Ø  Gypsum plaster thickness shall be restricted to 10 - 12 mm for walls or as per project requirements.

Ø  Back coat is recommended before applying gypsum plaster where the thichness of gypsum plaster is more than the specified thickness.

Ø  For Ceiling, gypsum thickness shall be restricted to 3-4 mm or as per project requirements.

Ø  Back coat of 6 to 10mm thick (cement sand mortar) shall be applied on block-work. Curing of black coat shall be done for 7 days before starting gypsum plaster.

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

Ø  Level strips of gypsum shall be made through full height of wall and shall be checked for right angles.

Ø  Fixing of door frames shall be done with reference of gypsum thiyyas.

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

Ø  Quality of bonding agent, gypsum Powder and fiber mesh shall be approved in advance.

Ø  For mixing of gypsum plaster, mix powder in water at ratio of 1 : 1.5 in the bucket or as per manufacturer recommendation. Water shall be tested and it should be suitable for construction work.

Ø  Mix thoroughly for 3 to 10 mins until the desired homogenous mix is achieved.

Ø  Ensure the mix is free from lumps before use.

Ø  Proper mixing equipment shall be used for mixing.

Ø  The gypsum mix shall be prepared on watertight bucket and consumed with in 20 to 25 minutes after adding water or as per manufacturer recommendation.

Ø  Mixed material to be applied by trowel and leveling to be done to produce unfinished surface.

Ø  Slurry of gypsum plaster to be applied on unfinished surface to finish up the final surface.

Ø  Thickness of layer of final surface finish shall be  10 to 12 mm for Wall and 3 to 4 mm for ceiling or as per project specification.

Ø  When the work is suspended at the end of the day, the gypsum plaster shall be left cut clean to line both horizontally and vertically.

Ø  When gypsum plastering is resumed the edge of the old work shall be scraped, cleaned and wetted with water before gypsum plaster is resumed.

Ø  Successor activities shall be started only after taking clearance or completion of gypsum work.

 

Reference Documents

 

Sr.No	Document No	Title
1	IS 2542	Method of test for gypsum plaster
2	IS 2547	Specification for gypsum plaster