Wooden cladding offers several advantages for building exteriors, including design freedom, ease of installation, and ability to withstand stresses. Proper installation is important to prevent moisture damage - cladding should be sealed and finished before installation, with flashing added at joints and openings. Regular maintenance of finishes helps protect the cladding from swelling, shrinking, and discoloration over time.
2. INTRODUCTION
Wood is a product that combines inspiration, beauty, performance and environmental
advantage.
Wood is a renewable resource;
Wood products store carbon dioxide;
Comparatively, the manufacture of most wood products requires smaller amounts of energy;
and
Residues generated through the processing of wood can be reused in a variety of positive
ways.
Timber performs strongly in the acoustic arena - whether the objective is to enhance sound
or reduce sound
While timber is indeed a combustible material, in construction it has significant insulating
properties and burns in a slow, predictable and measurable way
3. Wooden cladding offer the design freedom, ease of
handling, range and natural beauty of timber.
It can create a building to suit almost any
environment, taste or style.
It has an inbuilt flexibility that provides natural
advantages on sites subject to high winds, extreme
climate, highly reactive soils, subsidence or earth
tremors.
The natural resilience and high strength to weight
ratio of timber enables it to withstand far greater
stresses and movement.
Modern finishes give a long lasting and attractive
appearance to timber cladding
6. CLADDING BOARD SELECTION
When specifying cladding boards there are a number of points that should be
considered:
The appearance required by the architectural style
Availability and cost
Ease of installation and maintenance
Prevailing climate and thermal performance required for the building
The need, if any, for above average structural strength, which some specific
types of cladding will provide
Local government regulations or statutory requirements
Designers should be fully informed when making their decision. Specific
advice is available from suppliers or Timber Advisory Services.
7. SIZES AND PROFILES
Timber cladding is generally
produced from 150mm to
200mm wide boards,
anything wider increases the
risk of cupping or splitting
common types of
weatherboard sections
and their most common
names are :
8. PROTECTION OF CLADDING
Sarking
Sarking is a waterproof but vapour permeable flexible sheet material that is fixed
directly behind timber cladding. When water penetrates the cladding it serves by
directing the water away from the structure to avoid it pooling and lodging within the
frame.
Vapour barriers
Depending on the type of construction, the intended use of
the building and the climate of its location, a separate
vapour barrier may be required.
The potential for condensation of water vapour within a
frame is high when significant temperature differences
exist between indoor and outdoor environments.
Flashing
While sarking is used for general waterproofing but is
not always compulsory, flashing is used at corners,
vertical joints and around openings and is
essential for ensuring that water is prevented from
penetrating the wall frame cavity.
9. PRE INSTALLATION REQUIREMENTS
Prior to installation, cladding should always be suitably protected against the
elements, correctly sealed, prepared and then installed promptly.
The common pre installation considerations are outlined below-
Storage and handling
Timber cladding must be kept dry and clean
Without protection, water marking, moisture absorption or excessive heat build
up can occur, causing staining and or distortion of the cladding
Any storage shed or protective cover must be waterproof but also allow for the
free flow of air
Pre finishing the boards
The surfaces of cladding should be properly sealed and prepared so as to
provide a suitable base for subsequent finishing coats.
Areas not exposed to the weather should also be sealed to prevent moisture
movements.
10. DESIGN
To avoid moisture uptake, timber cladding on walls
should finish at least 150mm above ground level.
The bottom edge of the cladding should be cut to slope
at an angle of 15属 to shed the water away.
A gap should be left to prevent moisture in the
masonry from being taken up by the boards.
Ends can be sealed and the joint protected by a
coverstrip set in mastic
INSTALLATION DETAILS
11. FASTENER RECOMMENDATIONS
Preferred spacing of studs or fixing battens is
generally 450mm and 600mm.
For timber cladding, non corrosive nails such as hot
dipped galvanised, should always be the first choice.
Flat head nails may be used to provide additional
restraint of treated pine and Western Red Cedar
cladding.
silicon bronze nails will provide a superior
appearance when Wester Red Cedar is coated with a
natural or stained finish.
12. JOINTS BETWEEN BOARDS
To avoid unnecessary exposure of ends,
single length boards should be used on
exposed walls, wherever possible.
Tight fitting joints are achieved by
cutting a board slightly over length,
bowing to get it into position and
pushing it into place, as demonstrated
by the following figure
13. FINISHES AND MAINTENANCE
The regular application of water repellent finishes reduces the effects of swelling and
shrinkage caused by moisture content changes.
Ongoing sunlight exposure will change the surface color of uncoated timber to silver grey.
The graying of timber cladding will vary depending on the degree and level of exposure.
Timber specified for such applications should be a naturally durable species or CCA
preservative treated softwood. All timber, however, requires some finishing and regular
maintenance to offer an extended service life.
Whether a natural, stain finish or paint system is used, the manufacturer's recommendations
for application must be followed precisely to ensure the most long lasting result is achieved.