What is Plastering?

Plastering the process of applying thin cover of cement mortar over the exposed surface in order to safeguard against penetration of rain water and other atmospheric agencies. It improves the appearance of the structure and gives decorative effect to the interiors.

Check it out for more Launceston Plastering Tasmania information.

For good plaster, it is essential that the plaster should have proper bond with the surface of masonry to be plastered. For this the surface should be prepared by adopting following steps.

All the projections extending more than 13mm from the general face of the masonry should be knocked off.
All the joints in the masonry should be raked for a depth of about 20mm for good bonding between the cement mortar and masonry.

Oily, greasy and any efflorescence spots should be removed by brushing or scrapping.

On old surfaces, the surface should be made rough before applying the plaster.

Before applying plaster over the surface, it should be thoroughly washed by water to remove any loose material and keep it wet.

Water to be used for plaster work should be potable and free from soluble salts. Read our article on Tips for water used for construction

Uniform thickness of plaster should be maintained to avoid irregular finish.

Usually on ceiling 12mm thick and on walls 15mm thick plaster should be done.

The proportion for plaster on ceiling should be richer than 1:3 and for walls it should be richer than 1:6.
The plaster should be cured by sprinkling water at least thrice a day for minimum 7 days.

So remember, plastering is the way smooth walls were constructed in order to cover a rough textured substrate wall. Historically it was made by slaking lime in water and adding sand, gypsum and fibers, usually horse or some other animal hair. The slurry sets up with time so the mix had a working life where it could be smoothed by trowel onto the wall. It could also be cast into decorative mouldings which could be applied as cornice mouldings which were affixed using the slurry as glue. Also several techniques were used to apply decorative patterns, usually on ceilings.

These days the slurry is formed into paper wrapped wallboards at a factory, eliminating the need for the animal hair which helped to make it stable. When these boards are affixed to a wall, the cracks between them are filled with a gypsum compound and either paper or mesh fiber tape and finished off with successive thin coats of compound to smooth out the joints.

Click the link to learn more about Launceston city Plastering.