Suspended ceilings and Varnish

Suspended ceilings

 

 

A suspended (false) ceiling is the construction below the roof/ slab. Ceiling is the false structure (not load bearing) in overhead of the room below the roof. It has a framework suspended (supported) from the main structure, usually in the roof/slab and covering material is then fixed on the frame. It forms void between the ceiling and the roof/slab. This void is used for housing electricity trunk-lines, AC ducts, pipes etc.  It is frequently made of wooden frames and planks are fixed on it, Metals and other materials may also be used for the ceiling. The ceilings are also covered by rails, and panels in different patterns. Depending on the purpose, plaster boards, straw-boards, paris-boards etc, are also secured to ceilings.

 

Uses

 

  • For pleasing appearance.
  • Space for housing utilities, pipes, electrical wires etc.
  • Sound and heat insulation.

 

 

 

Requirements of suspended ceilings

 

  • Easy to construction.
  • Easy to clean, repair and maintenance.
  • Confirm the building standards and norms of the country.
  • Provide adequate means of access (enough space) for maintenance of concealed services therein.
  • Confirm the module of the building in accordance with the standards.

 

Types of suspended ceilings

 

According to use of material,

 

  1. Timber(bamboo, plywood, wooden planks etc)
  2. RCC
  3. Metal (steel, aluminum)
  4. Composite
  5. Gypsum board
  6. PVC board
  7. Straw board
  8. Glass
  9. Paper
  10. Textile, and others

    According to construction methods

  1. Jointless
  2. Jointed
  3. Open
  1. Joint less ceiling
  • It is monolithic in appearance and no joints can be seen on the surface.
  • This can be done by applying plaster on the ceiling plaster board/expanded metal lathing or spraying of asbestos/ vermiculite cement/ any other chemicals may be made on the metal background.
  1. Jointed ceilings
  • The joints on the ceiling may be made in decorative appearance.
  • The frame is made according to the desired shape and sized ceiling boards. Ceiling materials may be fixed with spring clips or nails/ screws.
  1. Open ceiling
  • The frame is fixed in such a way that voids are formed to give virtual effect. Voids are largely provided for decorative purpose. This may be a means for acoustic absorption as well.


    Procedure for ceiling fixing

  • Ceiling joists are fixed on desired height from the floor, if necessary, vertical struts are fixed to set joists.
  • Battens are than fixed on the joists.
  • Ceiling material, such as; planks, plywood, metal sheets, bhakary etc. is fixed on the battens.
  • Finally, painting and finishing is done.


    Varnish

  • It is the clear and pale solution of resinous substance dissolved in either oil turpentine or alcohol. The solution on drying forms a hard, transparent glossy film on the varnish surface.

Importance of varnish

 

  • The varnish applied on the decorative surfaces enhances the appearance of the paint.
  • Safeguards the wood work from atmospheric agents.
  • Increases the durability of paint.

 

Types of varnish

  1. Oil varnish – Oil & resin dissolved in volatile liquid (takes 24 hours to dry).
  2. Spar varnish – Used in spar & other parts of ship, weather resistance.
  3. Flat varnish – Dull appeared varnish, addition of more wax, metallic soap etc.
  4. Asphalt varnish – Dissolving asphalt in linseed oil & gives black color, used for metal.
  5. Spirit varnish – Resin dissolved in volatile liquid (spirit) and fast to dry.