Partitions and finishes-slideshare


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Partitions and finishes-slideshare

  1. 1. Partitions and finishesMaking the interior usable
  2. 2. Partitions• Internal walls which subdivide rooms• Can be load bearing or non load bearing• Load bearing partitions can be treated like external walls, but without the need for rain resistance• Non load bearing partitions are different
  3. 3. Finishes• Finishes can be internal or external• Finishes can be thick, property changing, or thin, cosmetic.• Some finishes are integral to the nature of partitions, so will be considered first.
  4. 4. External finishes• Dry finishes – claddings – Timber boarding – Tile hanging – Corrugated metal or plastic sheeting• Wet finishes-renders – Renders, either cement or lime plaster based – Paints, either cosmetic or protective
  5. 5. Dry claddings• Hidden faces of cladding must be ventilated and dry• Exposed faces must be out of contact with ground and allowed to dry
  6. 6. Keep it dryWooden cladding: Structural wall: can beventilated behind, out masonry, timberof contact with the framed or even anground. Best to use a open steel framerot resistant woodsuch as western redcedarVentilation: free flowof air using battensand gaps
  7. 7. Remedial cladding• Insulated dry external cladding can be fixed as a remedial measure to thin, cold damp walls or over failed roofs
  8. 8. Upgrading and old, cold but sound wall Old, cold wallOld, cold wall New cladding on Old, cold wall battens Insulation behind cladding Vapour barrier between old wall and warm side of insulation
  9. 9. Wet claddings: rendering• Rendering refers to covering an external wall surface with a plaster• Renders change the appearance of a wall and can improve the performance• Traditional renders were lime plaster based, but modern ones are largely portland cement based.
  10. 10. Lime plaster rendering: aka “pargetting” and “stucco”
  11. 11. Working with stucco• Stucco needs to be strongly keyed to the sub surface – Keying can be grooves in the brickwork, heads of partly driven nails, or in modern work, stainless steel meshes fixed to the sub surface• Any lime based finish must be protected form the rain – Good roof overhangs – Painted finish
  12. 12. Cement based rendering• Modern cement based renders are basically thin layers of concrete• Basic rule is the render must be weaker than the supporting wall so that the render fails first• Render should also be slightly flexible• Both achieved by concrete admixtures, often incorporating some lime.
  13. 13. Rendering on RAC campus WoodlandsBledisloe Court Coad Court
  14. 14. Why render a building?• For appearance, as on the RAC campus – Cheaper than natural stone – More sympathetic than artificial stone• Improved performance of old walls – Rendering can cover cracks – Extra layer can help rain resistance – Render can cover a new layer of external insulation
  15. 15. Internal finishes• Thick finishes – Wet linings • Lime plaster • Gypsum plaster – Dry lining • Plaster board • Timber lining• Thin finishes – Paints – Varnishes (timber only) – Stains (timber only)
  16. 16. Plaster• Plasters are thick, gel like materials applied to rough walls to give a smooth finish.• Plastering is a highly skilled trade• Plasters are either traditional lime plasters or modern gypsum plasters.
  17. 17. Lime plaster• Lime plaster – Traditional, mixture of lime (calcium carbonate CaCO3, derived from limestone or chalk) with sand, water and possibly a binder like horse hair – Highly alkaline, never sets truly hard, very flexible and self healing – Lime is a dangerous, irritant chemical – Lime plasters generally used for conservation work on historic buildings
  18. 18. Gypsum plaster• Gypsum is calcium sulphate (CaSO4) and a naturally occurring mineral in a hydrated form• Plaster of Paris is pure gypsum• Gypsum building plasters usually contains sand to bulk them out• Gypsum plasters are non-irritant, set hard and expand slightly on setting, taking up any shrinkage cracks• Vast bulk of modern building plasters are gypsum based
  19. 19. Plastering a wall• Three stage process – Dubbing out (filling hollows and cracks) – Base coating (12- 15mm layer levelling wall surface) – Skimming (3mm smooth finishing coat)
  20. 20. Plastering a wall• Three stage process – Dubbing out (filling hollows and cracks) – Base coating (12- 15mm layer levelling wall surface) – Skimming (3mm smooth finishing coat)
  21. 21. Plastering a wall• Three stage process – Dubbing out (filling hollows and cracks) – Base coating (12- 15mm layer levelling wall surface) – Skimming (3mm smooth finishing coat)
  22. 22. Plastering a wall• Three stage process – Dubbing out (filling hollows and cracks) – Base coating (12- 15mm layer levelling wall surface) – Skimming (3mm smooth finishing coat)
  23. 23. Dry lining• Walls can be dry lined with wooden boarding, but most common finish is plasterboard.• Plasterboard is one of the cheapest but most versatile building materials.• Basic plaster board is a set layer of gypsum plaster covered with strong paper• Plasterboard can also be foil backed as a vapour check or foam insulation backed as a complete internal insulation and finishing system
  24. 24. Dry lining by direct adhesion
  25. 25. Foam backed plasterboard• Foam backed plasterboard will insulate effectively• Boards must be secured mechanically as well, i.e. with nails or screws, to prevent it falling off in a fire.
  26. 26. Finishing plaster board• Joints covered in fabric tape and thin layer of plaster• Whole surface covered in a thin skim coat 3mm thick
  27. 27. Partitions• Load bearing partitions generally built in blockwork with a plaster/plasterboard finish• Non load bearing partitions – Timber framed with plasterboard finish both sides – Laminated plaster board – Steel studwork with plasterboard finish
  28. 28. Building a stud partition
  29. 29. Building a stud partition
  30. 30. Building a stud partition
  31. 31. Building a stud partition
  32. 32. Building a stud partition
  33. 33. Building a stud partition
  34. 34. Building a stud partition
  35. 35. Building a stud partition
  36. 36. Laminated plasterboard partition
  37. 37. Laminated plasterboard partition
  38. 38. Laminated plasterboard partition
  39. 39. Laminated plasterboard partition
  40. 40. Laminated plasterboard partition
  41. 41. Laminated plasterboard partition
  42. 42. Laminated plasterboard partition
  43. 43. Laminated plasterboard partition
  44. 44. Thin finishes• Thin finishes can be classed into opaque (paints) or transparent (varnishes).• Staines are not a true finish, but change the appearance of timbers and have water repellent and anti- fungal components.
  45. 45. Paints• All materials can be painted to – Improve appearance – Change colour – Protect base material• Paints always applied as a system – Primer: acts as a glue between base surface and paint system – Undercoat: highly pigmented, forms body of the system – Top coat, usually impermeable, may be glossy, gives final colour and seal
  46. 46. Varnish• Transparent finish• Only used on wood• Primers and undercoats can’t be used because of transparency• Multiple layers needed• Usually requires refinishing a regular intervals particularly if exposed to sunlight
  47. 47. Stains• Pigmented, largely transparent chemicals with water repellent and fungicidal qualities• Designed to soak into timber and give it a weather resistant, coloured surface• Works well for exposed structural timber, such as fences• Much used for window frames in the 1970-80s with poor results. Water still gets into the joints• Easy to restain, hard to refinish with paint
  48. 48. References• Lafarge are the largest plaster and plasterboard manufacturers and produce very good technical literature:•• Lafarge dry lining manual – /drywall_manual/default.html• Any building textbook will give details of internal plastering and partitioning systems