In This article I have explained the procedure of Plaster and important steps before plastering work.
Plastering: A process of covering the blocks walls and ceiling with a smooth finish by plaster materials (a mixture of Cement and sand by a defined ratio 1:1/5,1:2,1:3 etc. as per the work requirements)
Pre-plaster inspection steps:
- First of all, to check all the dimension(Sizes) of rooms
- Check Angle/Diagonal of rooms
- Check opening size of Doors & windows
- Check verticality of Brick or Block wall
- To make sure that all MEP services (Mechanical, Electrical & Plumbing work) has been installed.
- To ensure that all MEP services has coverd with wire mesh.
- To ensure Corner beads are installed
- To check that Plastering mesh is installed between concrete & masonry surface.
- Dust & other lose material have been removed and cleaned
- After ensuring all the above steps. guide point to be fixed on each wall which is a reference for plastering level & thickness of plaster the distance the guide points should be as per the aluminum straight edge length.
- A rush coat to be applied on the wall surface and after drying the surface plaster work to be carried out
- Plastering work to be done as per the specifications like lime finish, trowel finish, sponge finish, rough plaster and zone of application clarified from architects.
- Do not plaster for a thickness of more than 15mm. In case it is required, the plastering should be done in 2 coats. The first layer applied should be cured for a day before applying the subsequent coats.
- All surfaces in concrete should be hacked/Chipped before plastering, for making a good bonding between plaster and concrete.
Care to be taken during Plastering:
- All surfaces to be plastered must be wet to prevent absorption of water from plaster.
- Mix shall be kept as per specification but generally it is 1:2 or 1:3 for ceiling and 1:3 or 1:4 for wall plastering.
- Mix of mortar must be done using Measuring Box (Farma) for volumetric batching.
- Mix thoroughly for uniform mix and the mortar should be used within 30 minute to 1-hour maximum.
- After plastering check the surface for undulations using halogen lamps. Yellow light is thrown on the plastered wall from one side shows undulations, if any, rectify it immediately while the plaster is still fresh. All cut-outs such as fan, junction box, electrical box and skirting line should be finished to properly and should be homogeneous along with surface.
- Grooves and mortar bands should be given while the plaster is wet.
- If lime rendering is required, do it within 3 to 4 hour of the setting of cement mortar after plastering.
- After plastering work completed, curing to be done for minimum 3 days
- Potable water/ sweet water to be use for curing
- Check for smooth finish using spirit levels for undulations, cracks and evenness/straightness in vertical and horizontal directions.
- Ensure plastered surface is cured for the entire recommended period.
- Ensure the 1-meter level markings are made along all walls. Measure the ceiling from this level – it should be even at all points. (Check for ceiling plaster)
- Ensure plastering thickness is even at all points during plastering.
- Ensure availability of specialized trowels to obtain different structural finishes for the external plastering.
- Check for undulations and unevenness by using spirit levels.
- Ensure all plastered surfaces are cured for the entire specified period.
Care to be Taken After Plastering:
- Cure the works for a minimum of 7 days.
- A proper record to be maintained of each day work so each activity can be tracked easily. Write the date of plastering on the wall/ceiling with a permanent marker. (So you can track the curing days).
- All mortar waste stuck to walls & floor shall be cleaned properly after each day’s work.