Selecting and fixing finishes
(Part 6: Interior Wall and Ceiling Cladding)
Copywriter: Steve Connard
6. Interior Wall and Ceiling Cladding
Once the windows, doors and exterior wall cladding are complete, the house is at lockup stage and work on the interior can commence.
Commonly plasterboard is glued and nailed directly to the underside of the roof trusses but the manner of fixing can vary. If there is a second story above a ceiling joist will need to be added and the plasterboard is attached to this.
For residential buildings the choice of ceiling claddings is as endless as your imagination. But the choice is usually based upon what style of house you have, what type of look you are trying to achieve and how you want to deal with the junction between the ceiling material and the wall.
Plaster Board
Plasterboard is a laminated sheet of cardboard with a core of gypsum plaster. It is the most common method of wall and ceiling cladding in Australia. Any joins, gaps and holes are either filled in with gypsum "putty" or taped and plastered which can then be sanded smooth to create a perfect and seamless surface.
The straightness of plaster walls is only as good as the framing to which it is fixed. A straight edge should be used to check that wall studs, noggings and ceiling joists are in true alignment and trimmed back or packed out where necessary. All surfaces should be clean and dry.
The thickness of the board depends on the distance between studs or ceiling members but is generally 10 or 13 mm for walls and 10 mm for ceilings. For ceiling with joists every 600 mm, special lightweight plasterboard for ceilings with anti-sag properties should be used. For walls in wet areas plasterboard is not used and a fibre cement sheet is required.
Special acoustic plasterboard can be purchased and used where sound insulation is required in areas such as a common wall between bedroom and living area or bedroom and bathroom etc. http://www.bradfordinsulation.com.au/Products/Residential/Acoustic-insulation.aspx
Timber Boards
Gyprock and painted shiplap timber boards
Timber boards may be a thankful alternative to the omnipotence of plasterboard, but they are more expensive and not that easy to install. They are often used on vaulted and cathedral ceilings.
Timber boards will only be as straight as the battening to which they are fixed. They also require fire proof kraft paper to be laid between boards and ceiling joists. (This also helps to control dust that may fall from the ceiling cavity.)
Prefinished timber boards are available with tongue and grooved which makes fixing easier. They come in a variety of timbers. Light coloured timbers (and timbers that don't darken with time) are best for dark timber will make the room seem smaller.
Timber panels
Prefinished timber sheets (http://www.taittimber.com.au/timber_panelling.htm) that look like natural boards are available in a variety of timber styles, grades and widths (81mm, 106mm, 131mm widths.)
Some timber panels such as those from Boral (http://www.boral.com.au/Brochures/orders/PDF/Panelwood%20PP-02-0608.pdf?company=Plywood) are only made for painting.
Most panels are tongue and groove for easy assembly. Timber panels offer a cost effective alternative to natural timber boards, and in the right situation can look very good, however they will always look like panels.
Plywood
Bleached and satin treated plywood wall cladding
Semigloss-treated plywood ceiling in herringbone_pattern
Plywood must be a serious consideration for cladding a contemporary environment. It feels modern, and is both welcoming and warm. For that reason it works with all types of steel such as Zincalume and Colorbond.
Plywood can be bleached (hydrogen peroxide and sodium hydroxide), treated with oil or water based sealants to enhance its natural appearance, and even tinted. Any treatment will increase its sheen and brighten its look. Plywood comes in various grades and panels need to be selected with care so that their colour and grain are similar.
Evolution plywood from Boral is rough sawn plantation pine cladding that uses the same strong bonding resins as used in marine ply. It is available in solid, grooved or V Grooved, shiplapped or butt joined, and can be purchased pre-primed if it is to be painted. The rough sawn "V" shaped groove looks good next to fibre cement or Zinacalume.
A more upmarket type of plywood is the quite beautiful hoop-pine which, due to its finer finish, works well next to white plasterboard.
If plywood is to be fixed to the wall with a groove (shadow line) between panels, the timber beneath the groove is best painted matt black. The join between panels, if exposed, must be exactly the same width; which some times is tricky if walls are not square. Fixing timber sheets for ceilings in this manner is very difficult due to the fact that it's hard working overhead with large panels (and will require 2 or 3 people to do it) and a ceiling is rarely truly square.
Alternatively, a strip of timber can be fixed over the groove. But this method, particularly for the wall joins, can detract from the appeal that an expanse interseting timber provides. (It is also the old fashioned way of fixing panels.)