EXTERIOR CLADDING / FINISHING

Transcription

CARPENTRY - HOUSING
EXTERIOR
CLADDING /
FINISHING
This text introduces subject matter related to cladding, finishing and enclosing timber
wall frame cottages. It builds on knowledge and skills acquired during the first stage,
which should be revised and practiced throughout the course.
Reference may be made to “Basic Building and Construction Skills”, produced by
TAFE and Addison, Wesley, Longman Australia Pty Limited, to re-examine and
reinforce these basic skills.
Various traditional and alternative types of cladding materials and their cutting and
fixing techniques for timber framed cottages are outlined. It also addresses methods of
attaching cladding materials to masonry surfaces and the enclosing of a timber framed
cottage using a veneer of brickwork.
Also, calculation of sheet and board material quantities and costs is covered.
Note: These cladding materials may also be used for steel framed walls.
A comprehensive ‘Glossary of Terms’ is included at the end of the text, which provides
a detailed description of trade terms, technical content and some trade jargon.
©TAFE NSW Construction and Transport Division
1
EXTERIOR CLADDING/FINISHING
INTRODUCTION TO CLADDING
A cladding may be defined as being the surface covering or skin of the external walls of a
framed, or partly framed, building. Materials used may include timber, manufactured board or
sheet products, F.C. sheeting with a rendered finish known as ‘Stucco’ or a tyrolean finish
applied with a Tyrol gun, also known as ‘Conite’, brick and/or masonry veneer, metal backed
brickwork and PVC or Aluminium siding.
The cladding may enclose the whole building or only sections of the building such as:
• the walls to a second storey addition;
• infill panels above or below windows;
• one wall of an upper floor where it is not possible to support brickwork;
• gable or gambrel ends;
• dormer window walls;
• irregular shaped walls of a semi-octagonal ended room;
• separate framed garages; and
• low cost extensions.
In many cases sheet, strip, shingle or board type claddings are used an inexpensive means of
enclosing walls or to create a featured appearance.
FUNCTION OF CLADDING
Claddings are designed to carry out the following functions:
•
•
•
•
•
•
withstand and protect the building from weathering by the elements, i.e. sun, rain, wind,
snow, etc;
provides additional strength by acting like bracing to prevent racking under load;
prevents the entry of unwanted persons, animals, insects, etc;
provide a pleasing or alternative aesthetic appearance;
provide an additional means of insulating the building against heat and cold; and
provide an insulation against noise by reflecting or absorbing sound.
Fig. 1 Typical building enclosed using cladding material
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CARPENTRY - HOUSING
TYPES OF CLADDING
SOLID TIMBER WEATHERBOARDS
Timber, with good durability characteristics, provides a long lasting wall covering provided it is
correctly and regularly maintained. Suitable chemical impregnation, external oil or paint
applications will ensure the timber withstands the effects of weathering, timber decay and pest
attack.
Not all timber is suitable for external use, therefore only Class 1 or 2 durability timber is
recommended. Untreated Class 3 and 4 timbers such as Oregon, Radiata pine, Tasmanian oak,
etc. shall not be used for weather exposed structural members and are not recommended or
preferred for any other external purpose.
Note: Class 4 timbers may be upgraded for external use if they have been pressure treated in
their green state with a preservative such as CCA (Copper Chromium and Arsenic salts), which
turns the natural colour of the timber a characteristic copper green.
Suitable timbers for external use are as follows:
TABLE 1
NATURAL DURABILITY OF THE HEARTWOOD OF TIMBER
CLASS 1
White Cypress pine
Ironbark
Grey gum
Tallowwood
Turpentine
CLASS 2
Spotted gum
Kwila (Merbau)
Blackbutt
New England Blackbutt
Western red Cedar
Yellow & White Stringybark
River Red gum
Boards may be placed vertically, horizontally, diagonally or in patterns like herringbone:
VERTICAL
HORIZONTAL
DIAGONAL
HERRINGBONE
Fig. 2 Common weatherboard placement
3
COMMON WEATHERBOARD PROFILES
Weatherboards are designed to shed water and prevent wind passing through the joints. The
joints may be simply lapped, rebated or have a combination of a rebate and groove. There are
various profiles, which have also been copied in alternative materials, to allow the user to
create a functional and decorative surface.
Most timber weatherboards have a shallow warping groove milled into the back surface to
reduce the amount of warping or cupping, which occurs naturally in wide timber boards.
Pliable, permeable sarking is often used as a backing to increase the insulation and
weatherproofing properties of the boards.
SPLAYED, CHECKED AND
CHAMFERED
SPLAYED
RUSTICATED
DOUBLE LOG CABIN
SPLAYED, CHECKED AND
NOSED
SEMI-RUSTICATED
DOUBLE TEAR DROP
Fig. 3 Typical timber weatherboard profiles
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SHIP LAP
CARPENTRY - HOUSING
METHODS OF JOINTING AND CONNECTING WEATHERBOARDS
Straight jointing
Weatherboards are designed to be joined on a stud by butt jointing and skew nailing to hold the
ends tight. The ends of the boards are cut square, or slightly undercut to produce a tight surface
fit, and the end grain sealed with an appropriate pink or white timber primer. The primer is
designed to prevent the end grain absorbing excessive moisture, i.e. above 18% moisture
content, which will result in timber decay starting.
The ends of the boards should be pre-drilled to prevent end splitting during the nailing process
and if sarking is not used a strip of flashing, similar to ‘Alcore’, should be placed directly
behind the joint to prevent water penetration to the frame.
Lining
Joined board
Stud
Joint
Flashing
Primed
end grain
Fig. 4 Straight jointing on a stud
5
Internal corner jointing
The internal corner connection between weatherboards may be made in several ways. The
boards may be scribed over oneanother, which is time consuming, or they may be simply butt
jointed against an internal corner stop mould. If there is no sarking on the wall frames the
corner should be flashed for the full height, similar to the straight joint method. The end grain is
sealed with an appropriate pink or white timber primer. The primer is designed to prevent the
end grain absorbing excessive moisture, i.e. above 18% moisture content, which will result in
timber decay starting.
Corner mould
Corner studs
Approved lining
Corner flashing
were required
Internal corner
Stop mould
Approved
cladding
Bottom
plate
Fig. 5 Joining weatherboards at an internal corner
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CARPENTRY - HOUSING
External corner jointing
The external corners may be jointed the same as for internal corners, including a flashing
behind the weatherboards.
Alternatively, they may be mitred or be butt jointed with butt jointed cover battens placed over
the boards on either side of the corner. If butt jointing or mitring is used, the end grain must be
sealed with an appropriate pink or white timber primer to prevent timber decay.
These methods tend not to be used often, as the mitred joints are time consuming to fit neatly
and the cover battens form hollows behind them when used on profiled weatherboards, which
insect pests like house spiders tend to exploit.
Internal Lining
Weatherboards
Corner Mould
Skirting Block
Bottom Plate
Halved Joint
Fig. 6 Joining weatherboards at an external corner
Fasteners for weatherboards
Jolt or bullet head nails are used for all general
nailing of weatherboards as they can be punched.
All nails for external use must have a rust proof
coating such as galvanised, cadmium or nickelplated. Skew nailing is preferred as it prevents the
boards from lifting off the studs when the timber
shrinks. Spiral or helical shank nails may also be
used to improve grip.
.5
o2
2t
'T'
When 'T' equals the
thickness of the
weatherboard
Fig. 7 Coated bullet head nail
7
SHINGLES and SHAKES
These are thin rectangular shaped pieces of timber, which are lapped and fixed to provide a
waterproof surface for walls and roofs. They are mainly cut or split from Western red Cedar as
it provides the best splitting qualities and is very durable, i.e. Class 2 durability.
Shingles are sawn and tend to be used mainly for wall cladding, whereas shakes are split with a
rough texture and mainly used for roof coverings.
Types
•
•
•
straight split;
taper split; and
hand split and re-sawn.
They range is length from 450mm to 600mm and
widths of 100mm to 300mm. They are available in
strapped bundles for ease of stacking and storing.
When fixed in place the joints are staggered to
allow at least 40mm on either side under the join
with approximately 200mm exposed from the end
of one shingle to the end of the next. Shingles tend
to be used for feature walls or panels under or
above bay windows with a permeable building
paper being used under walls/facades and roofs.
Sawn Timber Shingle
Handsplit Timber Shake
Fig. 8 Typical shingle and shake
Wall studs
Galvanised flathead nails
50 x 25
battens
200
Permeable
membrane
Fig. 9 Shingles used as cladding on a wall/facade
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CARPENTRY - HOUSING
FIBRE CEMENT PRODUCTS
Background
In 1917 asbestos cement sheets began to be manufactured locally, by ‘Wunderlich’s, at
Cabarita, Sydney and by ‘Hardies’ at Camellia on the Parramatta river. Hardies called their
product ‘Fibrolite’, which was shortened and commonly referred to as ‘Fibro’.
By 1927 the available brands were ‘Asbestolite’, ‘Durabestos’, Eternit’, ‘Fibrolite’, ‘Fibrocement’, ‘Herculite’, ‘Poilite’ and ‘Titanic’.
These bonded asbestos products have since been withdrawn from the market but were widely
used up to the early 1980’s. Asbestos is a hazardous mineral fibre, which causes lung diseases
such as asbestosis, lung cancer and mesothelioma.
( Refer to pp. 143 – 145, Fibre and dust hazards, Basic Building and Construction Skills,
Second Edition, for further information and risk assessment)
The present day products are made by ‘James Hardie Building Products’ in a range of types and
finishes. Fibre cement, F.C., is manufactured by blending cellulose fibre (reinforcement), finely
ground silica (sand), and general purpose cement (hardening agent) with water, then rolling or
pressing it into the desired product. The finished product is very durable, serviceable and fairly
easy to fix.
SHEETS
PanelClad™ sheets are available in two types:
•
Stucco – which has a surface texture similar to swirled render. They are available in sheet
sizes of 2440mm and 3000mm long x 1200mm wide x 6mm thick; and
•
TextureLine – which has a surface texture similar to band sawn timber with regular
smooth grooves. They are available in sheet sizes of 2440mm and 2700mm long x 1198mm
wide x 6mm thick.
Hardiflex™ sheets are available in a smooth surface finish. They are available in the
following sheet sizes:
TABLE 2
SHEET SIZES
LENGTH mm
1800
WIDTH mm
900
THICKNESS mm
4.5
1800
1200
4.5, 6.0
2100
1200
4.5
2400
900, 1200
4.5, 6.0
2700
900
4.5
2700
1200
4.5, 6.0
3000
900
4.5
3000
1200
4.5, 6.0
9
Installation, Fixing and Jointing
12mm 12mm
Vertical Jointing
Vertical joints may be sealed and finished
using a number of options:
• Timber batten over joint;
• PVC straight jointer; and
• Special jointer for Textureline sheets.
MIN.
MIN.
Note: Vertical joints in Stucco sheets may
be nail fixed to studs, with a 3mm gap
between sheets, and then filled with a
flexible joint sealant.
Vapour
permeable
sarking
Fig. 10 Timber batten joint covering
12mm
Min
12mm
Fix jointing strip at
200mm centres
MIN.
Fix jointing strip
at 200mm
centres
Vapour
permeable
sarking
Vapour
permeable
sarking
Fig. 11 PVC straight jointer
Horizontal Jointing
Horizontal joints are waterproofed and
finished using a PVC horizontal flashing
mould for 6mm sheets and a PVC dripstrip for 4.5mm sheets. They are nail fixed
to studs and the mid rail of noggings.
Traditional horizontal joint treatments
involved fitting a metal ‘Z’ flashing
between sheets and covering the joint with
a nailed on fibre cement ‘C’ cover mould.
Fig. 12 Textureline jointer
Exterior wall
sheeting top
and bottom
Nogging
Sheet metal
flashing
Horizontal
cover mould.
Fig. 13 Traditional jointing method
10
12mm
CARPENTRY - HOUSING
PVC Horizontal
Flashing mould
Noggings
Nail or screw fix
to studs and
noggings at
200mm centres
Vapour
permeable
sarking
PVC Drip
strip
Vapour permeable
sarking
Hardiflex™
Sheet
Fig. 14 Horizontal flashing joint
Fig. 15 Drip-strip joint
Corner Jointing
Traditional internal and external corners were jointed with Aluminium extruded angles or
covered with quads to internal corners and fibre cement external corner angles.
Internal lining
Corner studs
DIVISION MOULD
Fibre cement
cover mould
Fibre cement
external cladding
Bottom plate
INTERNAL CORNER MOULD
EXTERNAL ANGLE MOULD
Stud housed into
plate
ALUMINIUM MOULDINGS
Fig. 16 Fibre cement corner moulding and extruded Aluminium mouldings
Alternatively, the corners may be covered with timber battens or PVC internal and external
jointing strips, as shown in Table 10.3.
11
Studs
Vapour permeable sarking
Studs
Flashing (not required where
reflective type sarking used)
Vapour
permeable
sarking
Sheet
Timber Batten
Sheet
Fig. 17 Timber batten to internal corner
Flashing (not required
where reflective type
sarking used
Timber Battens
Fig. 18 Timber batten to external corner
Accessories
The following products are recommended James Hardie accessories:
TABLE 3
SHEET ACCESSORIES
Hardiplank™
Cladding
HardiPrime™
Weatherboards
12
Shingled PrimeLine™
WeatherSiding
boards
CARPENTRY - HOUSING
CUTTING
Hand guillotine
Cutting fibre cement sheeting may
be carried out using a variety of
tools. The most common of these
methods is to use the hand
guillotine. The guillotine produces
a clean, straight edge by cutting
along the waste side of the line.
The width of the cut is equal to the
thickness of the cutting blade,
which is approximately 3mm.
Cut along line
with guillotine
cutters
Hand
Guillotine
Fig. 19 Using the hand guillotine
Score and Snap
A quicker and more popular
method is to score with a tungstentipped scoring tool.
While holding a straight-edge along
the desired cutting line, run the
scoring tool along the edge four to
five times. Support the scored edge
and lift the sheet upwards to snap it
off and form a clean break.
Straight Edge
Tungsten tipped
score and snap
knife
Lift to Snap
Score along straight
edge then lift sheet
upwards to form a
clean break
Fig. 20 Using the scoring tool
13
Circular holes
Small rectangular or circular holes
may be formed using an electric
drill to bore a series of smaller
relief holes around the perimeter.
This will weaken the sheet in the
required shape allowing the waste
to be tapped out with a hammer.
Regular sized holes may be cut
using a purpose made hole-saw
tool.
Note: Never punch a hole through
with a hammer only as this causes
the back of the sheet to shatter.
Holes may be
formed by drilling
around the
perimeter
Support edge
of hole to minimise
damage then punch
through with a
hammer
Fig. 21 Forming small holes
Fig. 22 Right and wrong methods of forming holes
Pocket cutting
Larger rectangular holes or
openings are formed by scoring
around the perimeter of the
required opening, creating a hole in
the centre, running a saw cut from
the hole to each corner and then
lifting the waste towards the scored
edge. Holding a straight-edge along
the scored edge will assist a clean
snap.
Straight edge
Lift to snap
Saw cut
Score between cuts
Fig. 23 Pocket cutting larger holes
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CARPENTRY - HOUSING
Hand sawing
Hand sawing is also an option,
however it tends to be labour
intensive and causes excessive
wear on the hand saw. This type of
cutting tends to be restricted to
short lengths and relief cuts.
KEY HOLE
PAD SAW
HAND SAW
Fig. 24 Various saws used for relief cutting
Electric shears
A power tool alternative to the
hand tools is the electric cutting
tool known as the ‘Fibreshear’,
which is basically a set of electric
cutting shears, similar to those used
on metal sheet materials.
Fig. 25 Fibreshear cutting tool
Fasteners for fibre cement sheets
Nails to timber should be 2.8 x 30mm long
with a protective coating such as
galvanised. The head of the nail should be
driven flush with the face of the sheet.
Fig. 26 Flat head nail
Screws to steel framing should be similar
to 22mm long Hardidrive™ external grade
with self embedding heads.
Fig. 27 Self embedding head scr
15
STRIPS and PLANKS
Fibre cement weatherboard and plank cladding produced by ‘Hardies’ includes PrimeLine™,
HardiPrime™, Shingled siding and HardiPlank™ .
They are available primed and non-primed in lengths up to 4200mm and thicknesses ranging
from 6mm for shingled siding, 7.5mm for Hardiplank and up to 9mm for the weatherboard
range.
Internal and External Corners
Corner finishing methods are similar to sheet cladding methods with the inclusion of separate
preformed metal joiners.
Corner Studs
Corner studs
Vapour permeable
sarking
Alcor flashing (not required
where reflective type sarking
used)
25 x 25 mm Timber Stop
Alcor flashing (not
required where reflective
type sarking use)
50 x 25mm Timber Stop
Zincalume Starter Strip
Ant Capping
TIMBER STOP CORNER
TIMBER STOP CORNER
Corner Studs
Corner studs
Alcor Flashing (not required
where reflective type sarking
used)
Alcor flashing (not
type sarking use)
Preformed metal internal corner
Preformed Metal
External Corner
Ant Capping
PREFORMED ALUMINIUM CORNER
(HARDIPLANK™ CLADDING ONLY)
PREFORMED ALUMINIUM CORNER
(HARDIPLANK™ CLADDING ONLY)
Corner studs
Corner Studs
Alcor flashing (Not required where
reflective type sarking used)
Aluminium continuous corner
fixed to frame at 600mm
centres
Alcor flashing (not
type sarking use)
Continuous aluminium
corner fixed to frame at
600mm centres
Zincalume starter strip
Ant capping
ALUMINIUM CONTINUOUS CORNER
Fig. 28 Internal corner treatment
ALUMINIUM CONTINUOUS CORNER
Fig. 29 External corner treatment
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CARPENTRY - HOUSING
Cutting and Fixing
Once the vertical gauge for the
boards or planks has been set out
and a level starting position
established, a template or lap gauge
is made from a short, narrow length
of timber. The gauge is used to
position the next row of cladding to
ensure they remain parallel and the
amount of exposure is the same for
every row.
Note: Use of the gauge is more
suited to plain splayed boards or
parallel thickness planks, which
don’t have a locating rebate or
check on the bottom edge.
Lap gauge cut to
suit the board
profile
The gauge will
ensure the correct
lap is maintained
Fig. 30 Using the lap gauge
Scribing block cut to
suite the profile of the
cladding
Where an external timber corner
batten is used, the boards or planks
should be scribed into position.
This is carried out by fitting one
square end of the piece to be cut
against the internal corner or
adjoining board, then using a
scribing block pushed hard against
the corner batten and marking the
outside edge. This allows for any
bend or bow in the corner batten,
which will show a gap if the
cladding is not scribed.
Run a pencil line
along the outside of
the scribing block
Corner batten
Fig. 31 Using the scribing block
17
Finishing around metal windows and doors
The heads of the frames are flashed
prior to fixing the cladding. The
flashing should extend past the top
of the architrave, by approximately
50mm, on the face of the lintel,
then be folded across the top of the
window frame, bent down over the
edge and neatly trimmed after the
architrave is fitted. The top of the
architrave is sealed to prevent
excessive water entering.
Weatherboard or
plank cladding
Window trim fastened
to frame and sealed
along top
Header
Timber packer to suit
Flashing
Trimmer
Timber Reveal
Caulking
Fig. 32 Head detail
The ends of the planks or boards
are cut against the outside of the
stile leaving a gap of approximately
3mm, which is filled with sealant,
to prevent capillary action if water
enters behind the architrave. The
architraves are fitted with the
outside edge being sealed.
Villaboard™ Lining
Stud
Sarking
to frame and sealed
Caulking
Weatherboard or plank cladding
Fig. 33 Stile detail
A sill flashing is run down over the
face of the cladding before the
architrave is fitted. The bottom
edge of the architrave is packed out
to allow any water that enters to
escape.
Caulking
Flashing
to frame
Sill Plate
Packer as required to
provide gap for
drainage
Sarking
Weatherboard or plank
cladding
Fig. 34 Window sill detail
18
CARPENTRY - HOUSING
General fixing to timber
Weatherboard or
plank cladding
20mm min
25mm min lap
12mm min
Vapour permeable
sarking
Vapour permeable
sarking
Concealed
nailing for
Hardiprime™
classic (shown)
or rough-cut
weatherboard
Fig. 36 Concealed nailing
40
30mm max.
18mm max
overlap
Fig. 35 Fixing plain profile boards and planks
Vapour permeable
sarking
Lap
Galvanised fibre
cement nails
25mm
25mm min lap
Use galvanised fibre cement nails of a suitable gauge and length, refer to accessories Table 10.4,
for fixing to timber studs. There are several special fixing accessories available for use with the
nails such as metal joint soakers, stud clips, Uniclips, as well as starter strips and corner strips.
40
Primeline™ Summit
weatherboard
Vapour permeable
sarking
Fig. 37 Fixing Heritage profile boards
Fig. 38 Fixing Summit profile boards
19
Jointing planks and boards
Where concealed off-stud jointing is required metal soakers are recommended, except for
Heritage type boards where Uniclips are suggested.
Fit metal soaker over plank end,
top and bottom then fasten plank
to studs.
Install next plank hard against soaker stops,
giving a 3mm gap between plank ends. Apply
masking tape both sides of joint. Apply James
Hardie Sealant into gap then wipe flush with
plank surface, using a damp cloth then remove
tape
3mm gap
STEP 1
STEP 2
Fig. 39 Metal soakers for off-stud jointing
On-stud jointing requires a gap of 3mm between the ends of boards to allow for filling with
sealant. HardiPlank™ off-stud jointing is carried out using PVC jointing strips.
Stud
Stud
Pack out stud with
timber off cut for
fixing end of plank
Vapour permeable
sarking
Vapour permeable
sarking
Pre-drill & fasten
20mm min from plank
ends
PVC Jointing
Strip
Provide 3mm gap,
tape both sides with
masking tape fill with
James Hardie sealant
and wipe surface
flush with a damp
cloth then remove
tape
Fig. 40 On-stud jointing
Fig. 41 Jointing HardiPlank™ off-stud
20
CARPENTRY - HOUSING
Accessories
The following products are recommended James Hardie accessories:
TABLE 4
BOARD AND PLANK ACCESSORIES
Hardiplank™
Cladding
HardiPrime™
Weatherboards
Shingled
Siding
PrimeLine™
Weatherboards
INSTALLATION of WEATHERBOARDS and PLANKS
STEP 1 Install sarking over the outside of the frame as required and fit all vertical internal and
external corner flashings.
STEP 2 The continuous internal and external corner accessories or battens must be fastened to
the frame before the foot mould or Starter strip is fixed.
STEP 3 Using a spirit or water level, establish a level line around the lower perimeter of the
frame and fix the Zincalume™ Starter strip.
STEP 4 Start the first plank against the starter strip, flush with the external corner.
Fasten the plank to the frame through the strip.
STEP 5 Fit either a metal soaker or jointing strip to the free end of the first plank. Continue
fitting the bottom course of planks until the perimeter is complete.
STEP 6 On completion of the first course, use a storey rod or lap gauge to position subsequent
courses. The joints at the ends of the planks should be staggered so there are no
continuous vertical or near vertical joints.
21
USES OF SHEET PRODUCTS (past and present)
Fig. 42 Old vertical sheets and battens
Fig. 43 Horizontal and vertical weatherboards
Fig. 44 Tudor style sheets and battens
Fig. 45 Stucco sheeting
Fig. 46 Modern vertical sheets and battens
Fig. 47 Sheets to gambrel end with battens
22
CARPENTRY - HOUSING
USES OF WEATHERBOARD and PLANK PRODUCTS (past and present)
Fig. 48 Old horizontal weatherboards
Fig. 49 Old splayed weatherboards
Fig. 50 Old double log cabin
Fig. 51 HardiPlank™ extension
Fig. 52 New HardiPlank™ upper end wall
Fig. 53 New HardiPlank™ upper side wall
23
ALTERNATIVE CLADDINGS and MATERIALS
There are many alternative cladding finishes for use with timber and steel wall framing. The
following details outline past and present types and systems:
FIBRE CEMENT MOULDED PANELS
Moulded or profiled sheets are available in a number of patterns. Older types of these profiles
were made using asbestos fibre for reinforcement, but modern types use cellulose fibre. Most
were used for wall claddings but others were mainly used for fences, such as Shadowline and
Coverline. Deeper profiled sheets such as Super-six were mainly used for commercial roof
coverings and some fences.
Overall width 1 145
Cover width 1 065
65 65
Overall width
375
25
Cover width
355
SHADOW LINE
17.5
LOG CABIN
Overall width
370
Cover width
355
Overall width 950
Cover width 915
45 125
16
17.5
WEATHERBOARD
COVERLINE
Fig. 54 Popular moulded panels
‘TYPE A’ EXTERIOR BONDED PLYWOOD
Plywood may be used as an external cladding with either a painted or stained finish. Its
properties include dimensional stability, strength and split resistance, but an exterior grade
plywood, i.e. ‘Type A’, must be used.
A wide range of sheet sizes and sheet thicknesses are available in different timber veneers. The
sheets are fixed with corrosion resistant nails.
Bond
Type A bond (Phenol Formaldehyde) is the same as structural marine grade plywood. It is a
durable permanent bond, which will not break down under fully exposed conditions.
Face grades
‘A’ grade faces should be specified where a clear finish or high gloss paint finish is required;
‘B’ grade faces should be specified where a normal exterior paint finish is required;
Note: Exterior grade plywood usually has a reduced quality ‘C’ or ‘D’ grade back.
24
CARPENTRY - HOUSING
TEMPERED HARDBOARD
Tempered hardboard is a manufactured hardwood timber product. Its composition is a selected
mixture of natural Australian hardwood timber fibres compressed under great heat and pressure
to form a dense, strong board, which is grainless, knotless, defect free and easily worked with
general carpenter’s tools. It has good weathering and durability qualities making it suitable for
exterior applications.
The most commonly used hardboard cladding is in strip or plank form known as ‘Weathertex
™’, which has been used since the mid 1960’s and still proves to be a popular cladding.
‘Weathertex™’ is available in four surface styles:
•
•
•
•
Plain;
Ruff-X;
Stylegrain; and
Ruff-sawn
They are produced in lengths of 3660mm x 200 and 300mm widths, by 9.5mm thick. The faces
are slightly tapered, when seen in section. The face, ends and edges are coated with a fungalresisting primer and the back is sealed against moisture penetration.
Jointing
Internal corners may be butt jointed against a square timber mould or the end of one board is
scribed over the other with a small notch taken out of the top corner to allow for lapping.
Corner
Flashing
Corner flashing
Corner mould
Scribed
boards
SCRIBED
BUTT JOINTED
Fig. 55 Internal
corner jointing
The length of boards is usually
joined using a white - PVC
‘H’-section off-stud joiner.
Fig. 56
PVC joiner
Off-stud
25
External corners may be finished against a corner batten or splay angle cut butt jointed and
fitted with special pre-formed metal corner pieces. These metal corner pieces are fixed by
placing the bottom flange under the planks and pushing them up until they are flush with the
lower edge. A nail is then driven through the hole at the top of the corner piece. Each row of
planks is fitted with the corner pieces progressively.
Ends of planks
splay cut and butt
jointed
Fixing hole
Single nail fixing
Metal corner pieces
Aluminium Corner Piece
Fig. 57 Finishing external corners
Spacing and fixing planks
Once the bottom row is levelled
and fixed off and the gauge or
amount of lap has been calculated,
make a simple timber or metal jig
or spacer block.
The block will allow each row to
maintain the same amount of
exposed plank by locating the
lower edge parallel with the row
below.
The planks are then fixed into
position using galvanised 50 x
2.8mm nails, which have a
countersunk head. These nails are
usually ordered and supplied with
the planks.
Planks nailed off to
spacer position
Spacer block
Fig. 58 Using the jig or spacer block
26
CARPENTRY - HOUSING
THIN BRICK VENEER
Thin biscuits are cut from normal full size bricks to approximately 25mm thick and inserted
onto a patent steel backing. The brick biscuits are attached to the steel backing’s by either
locking into fingers, which are pressed through the backing panel, or lock onto tongues by
using the pre-cut grooves on the top and bottom edges of the biscuits.
There are a number of systems available such as the ‘Kwik Brick Rail System™’ and the ‘Steel
Backed™’ system.
Both systems require the steel backing to be nail or screw fixed to studs or over existing
claddings, unless vinyl or aluminium as they do not provide secure fixing. Where a wall has no
original cladding, sarking should be fixed to the studs to provide a waterproof base.
Once the backing’s are in place and the brick biscuits attached, the joints are filled with a
specially formulated mortar applied using a mortar bag, gun or pump.
The advantage of this system is that it may be placed over existing weathered or outdated
cladding to provide a new, durable, maintenance-free surface or attached to new second-storey
walls where full size bricks would be impractical to use.
Note: Refer to individual manufacturer’s brochures for more information and detail.
Steel backing
Steel backing
Fingers
Brick biscuits
Brick biscuits
Short tongue
Long tongue
Fig. 59 Finger locking system
Fig. 60 Tongue and groove system
27
AERATED CONCRETE PANELS
Products such as CSR Hebel’s Powerpanel™ are manufactured from autoclaved, aerated
concrete, which creates a strong lightweight cladding panel system. The special concrete mix is
basically aerated and then steam cured under high pressure.
The panels are 75mm thick and reinforced with four steel bars running vertically, as well as
several transverse bars. The panels are flat and straight making them ideally suited to take thin
surface finishes with little preparation.
The aerated characteristic provides excellent thermal insulation properties and provides a 3hour fire rating, which exceeds most other external cladding ratings for domestic construction.
Note: Refer to CSR Hebel manufacturer’s brochures for more details, fixing and finishing
instructions
50
min
Top of windows/external doors
150
max
Carry coating
past eaves level
Timber or
Steel stud
20mm gap
Power panel
75 50
min min
G.L.
125 min
Max. spacing to suit
recommendations
Quad
20
14-10 x
65mm
HEX
TYPE 17
Refer to A.S.
2870 for design
D.P.C.
10mm gap for
drainage
Top hat
section
95
Fig. 61 Typical Powerpanel™ details
28
Timber
12-11 x 25
mm HEX
TYPE 17
or
Steel
10-16 x 16
HEX TEKS
CARPENTRY - HOUSING
BRICK VENEER CONSTRUCTION
Brick veneer construction is widely used in Australia, but is relatively unknown overseas. It is
basically a hybrid or mix of cavity wall and timber frame construction. The real frame of the
building is the timber frame with a 110mm thick leaf of brick cladding set 40mm, but not less
than 25mm, around it to give the appearance of full cavity brick construction.
This type of construction was experimented with back as early as 1903 in some country areas
and it was not until about 1928 that it became more widely accepted by municipal councils and
lending authorities. At the end of the 20th century it is now the most common method of
cladding used in domestic construction around Australia.
Brick veneer construction members
1
2
3
4
5
6
Bottom wall plate
Vermin-proof wire
Continuous ant capping
Damp-proof course
Attached pier
Wall tie
7
8
9
10
11
12
LEGEND
Brick air vent
R.C. strip footing
Ground level
DPC level
110mm Brick veneer
Corner blocking
13
14
15
16
17
18
Floor joist
Veneer tie
Diagonal brace
Common stud
Nogging
Bearer
Fig. 62 Brick veneer details
29
Veneer ties
These provide a link between the brick
veneer and the timber frame. They are
bedded a minimum of 50mm into the
brickwork every 7th course high (approx.
600mm), tilted up slightly to prevent water
travelling across the cavity to the frame,
and then nailed into the side or edge of the
studs at Max. 600mm centres. There are
several types of ties available from twisted
flat galvanised metal to heavy gauge
galvanised wire ties.
2 No 25 x 3
Galv. clouts
Foil
20
75-120
2 No 38 x 3
Galv. clouts
50
Min.
20
20
25-80
50
Min.
100
25
150
200
18 SWG galv. steel
Fig. 63 Typical veneer tie
1 No 38 x 2.5
galv. clout
20
Fig. .64 Fixing various ties
Vermin wire
Vermin wire is used for suspended timber frame floors and should be 150mm wide galvanised
wire mesh with Max. 12mm openings, designed to prevent vermin (rats and mice) from
entering the cavity from the sub-floor. The wire is bedded into the brickwork horizontally
around the perimeter and fixed to the edge of the bottom wall plate with clouts, or similar, at
Max.150mm centres. Rolled paper is laid on top of the wire during construction to make
removal of mortar droppings easier
Wall stud
Veneer tie
Skirting block
(skirting over 75mm)
Insulation foil
Bottom plate
12mm Galv. Mesh
vermin proofing
Continuous galv.
Steel antcapping
D.P.C.
Floor bearer
Floor joist
Half pier cap soldered at joints
to continuous ant capping
Approved vent
Attached pier
Fig. 65 Placement of ties and vermin wire
30
CARPENTRY - HOUSING
Allowance for frame shrinkage
The external veneer of brickwork remains stable while the timber frame members, which may
not be fully seasoned, tend to shrink in width and thickness causing a slight drop. If members of
the timber frame are placed in direct contact with the brick veneer, such as window and door
sills or eaves framing, the frame movement may cause cracking or dislodging of the bricks.
Therefore, a small clearance allowance is made at these positions of 10 to 12mm for single
storeys and up to 20mm for two-storeys.
12mm clearance
provided for
shrinkage of
timber frame
12mm clearance
provided for
shrinkage of
timber frame
Fig. 66 Alternative eaves construction showing allowance for clearance
Spanning openings
Where the brick veneer spans window and door
head openings the brickwork is supported on hot
dipped galvanised steel arch bars or lintels.
Narrow openings up to 1200mm may be supported
on flat bars with each end bearing at least 100mm
onto brickwork. Openings greater than 1200mm
shall be supported on angles with each end bearing
at least 150mm onto brickwork.
The centre of the opening should be temporarily
supported during construction to prevent
deflection.
Note: Refer to AS 4100, AS 3700 or BCA96
Housing for further information
10
0
n.
Mi
Fig. 67 Steel flat bar lintel
M.S. Flat
bar
0
10
min
Fig. 68 Steel angle lintel
Temporary
prop
Fig. 69 Temporary support during
construction
31
Ceiling Trimmer
Hip
Ridge
Rafter
Creeper
Hanger
Fascia
M.S. Dog
Ceiling joist
Purlin
Stud
Ceiling joist
Blocking
Ceiling batten
Nogging
Window head
Skirting
Top wall plate
Plate
Plate
Floor joist
Deep Floor
joist
Tongue &
grooved flooring
Solid
Blocking
Diagonal bracing
Plate
40mm cavity
Ceiling batten
External
brickwork
Bottom wall plate
Window head
Top wall plate
Veneer tie
Vent
Floor joist
G.I. Ant
Cap
Vermin proofing
Isolated brick pier
Floor bearer
Damp-proof course
Bottom wall plate
Bearer
G.I. Ant cap, D.P.C. under
110 Brickwork
Fig.
70
Two
R.C. Strip footing
M.S. Rod reinforcement
storey brick veneer frame details
32
CARPENTRY - HOUSING
SHEET METAL CLADDING
There are a large number of profiles
available for wall cladding use
produced by BHP such as Panel rib,
Custom orb, Mini orb, Trim-wall,
Easyclad Hi-Ten, Multiline and
Wallclad.
They are usually fixed vertically
using screws fitted with neoprene
washers for weatherproofing.
Stud
Nogging
Direction of
prevailing
winds
4mm Blind
rivet or side
lap screw
Woodscrew or drive
nail for timber or
self-tapping screw
for steel with ∅
16mm metal and
neoprene washers
Direction
of laying
Outside
corner
mould
Fig. 71 Typical panel rib sheeting attached to walls
Finish
Most cladding sheets have a Colorbond™ coloured finish or they may be left plain with a
Zincalume™ surface.
Colorbond™ is a process which coats the Zincalume™ base with a baked epoxy primer, then a
baked exterior colour finish. The underside is coated with a grey interior finish to provide all
over protection from weather and water vapour.
Fasteners
Fasteners may be fixed through the valley or crest of the sheet using one of the following
fastener types:
Fig. 72 Recommended fasteners
33
Fixing methods
Sheets may have secret or concealed fasteners or be fixed through the surface of the valley or
crest of the sheet.
Concealed fixing
•
•
•
Attach starting clips along a plumb line to the purlin, girt or row of noggings (see A);
Lock the first sheet into the starting clips and fasten the opposite edge (see B);
Lock the second sheet into the fixed edge of the first sheet and repeat process until the walls
are complete (see C).
Starting Clip
PURLIN OR GIRT
First cladding
Sheet
Drive screw
Second
Cladding Sheet
Drive screw
First Cladding
Sheet
PURLIN OR GIRT
PURLIN OR GIRT
Fig. 73 Concealed fixing
Exposed fixing
•
•
•
•
Attach the first sheet through the last valley on each purlin, girt or row of noggings;
Fit at least 5 fastenings to the valleys of each sheet on each purlin, girt or row of noggings;
Place the next sheet over the end of the first and fix through the crest, at approx. 500mm
centres for the height of the sheet;
Continue until all sheets are fixed.
Side Lap Stitching
Trough Fixing
Side Lap Stitching
Fig. 74 Exposed fixing
20.6mm
Approved screw
Washer set
Long
overlapping
leg
6.3mm
Fig. 75 Crest fixing detail
34
Anti-capillary
air space
CARPENTRY - HOUSING
PREPARING WALLS FOR CLADDING
STRAIGHTENING OF STUDS
Poor stacking, partial or uneven seasoning may lead to studs bowing, twisting or forming a
spring, which is a bend along the edge. These malformed studs may still be used but will
require some additional attention before the wall frames are finished and ready to receive
linings.
Once the wall frames are up and the ceiling frame is complete, the temporary braces are
removed from the walls. At this stage it may be necessary to go over the frames to complete the
fitting of blocks, loose or missing noggings and to straighten any studs with excessive spring.
As previously mentioned in Unit 8, this procedure is especially critical in the wet areas
(bathroom, laundry, toilet, kitchen) so that wall tiles may be laid onto a straight surface and to
allow kitchen cupboards to be easily fitted to straight walls. It is also important for cladding
materials as excessive spring in studs will show up in the line of the exterior surface, especially
where narrow weatherboards or planks are used.
Straightening long walls
STEP 1
Place a nail at the mid height of both ends of the wall and run a taught string line
between the two nails.
Place a block, say 20mm thick, under both ends of the string line in front of the
nails to lift the line off the face of the wall frame.
Note: Short walls may be checked with a straight edge instead.
Spacer block
Taught string line
Spacer block
Fig. 76 Positioning the string line
35
STEP 2
Using another short block of the same thickness as the end blocks, place it under
the line at each stud position. If there is a spring in the stud it will either create a
gap between the block and the line (stud is hollow on the outside) or it will not
allow the block to fit under the line (stud is rounded to the outside).
Checking studs for spring
using a third spacer block
Fig. 77 Checking studs for spring
STEP 3
If studs require crippling, follow the steps below to correct excessive spring:
1. Make a saw cut in the
centre of the hollow edge to a
depth of approximately half the
stud width:
Make sawcut half
depth
BOWED
2. Drive a thin timber wedge into
the saw cut while pulling the stud
straight. Skew nail through the
saw cut and wedge:
Push to
straighten
Drive
wedge
in
3. Nail a timber cleat to the face
of the stud over the saw cut and
wedge to reinforce the cut stud:
Nail cleat to
side
STRAIGHTENED
Fig. 78 Correcting spring in studs
36
Cut off
remainder
of wedge
STRENGTHENED
CARPENTRY - HOUSING
PREPARING MASONRY WALLS
Where external masonry walls are to be covered with a cladding, the wall should be checked
for straight, prior to any sheet or board fixing. Where the wall is out of plumb or has high and
low sections, timber grounds or metal furring channels are fixed at appropriate centres. The
grounds or channels may require some packing to maintain a straight line. This may achieved
by using non-compressible materials such as fibre cement strips, strips of Alcore folded to the
required thickness, strips of sheet lead, etc.
Grounds or channels for vertical sheet cladding should be placed horizontally and spaced at
900mm centres or as per manufacturer’s specification. Grounds or channels for horizontal
board and strip cladding should be placed vertically at 600mm centres or as per manufacturer’s
specifications.
Fixings
Structural adhesive
Structural adhesive
Where light loads are applied to walls,
wind loads are low or the cladding material
is lightweight, structural adhesives may be
used to attach the grounds to masonry.
Products similar to Maxbond® or Liquid
nails® may be used for this purpose.
Thicknessed timber
ground
Fig. 79 Structural adhesive
Masonry anchors
Special masonry fasteners may be used for
grounds or channels to support heavier
claddings. Screws and plastic plugs may
also be used.
Furring channel
Masonry anchor
Packing as required
Fig. 80 Masonry anchor
Nails
Nails driven using an explosive powered
tool may be used to fix grounds or
channels. Nails with a spiral shank may
also be used in conjunction with plastic
plugs, known as ‘spaghetti’ , which are
driven into pre-bored holes.
Packing as required
Spiral shank nail
for grip
Thicknessed
timber ground
'Spaghetti' plastic plug
Fig. 81 Nail and spaghetti plug.
37
WALL CLADDING CALCULATIONS
SHEET and STRIP MATERIALS
When ‘taking-off’ quantities for wall sheet cladding it is essential that a systematic approach be
adopted to avoid missing critical elements.
Example 1:
Calculate the number of 4.5mm thick fibre cement sheets and timber cover straps for a single
wall 6300mm long x 2400mm high. The sheets are 1800mm x 1200mm wide, fixed
horizontally staggering the vertical joints by half lapping. Joints are covered with 50 x 19mm
DAR straps.
2400
450
6300
Fig. 82 Single wall to be clad
STEP 1
Find the area of the wall:
Area
STEP 2
6.300
x
2.400
= 15.120m²
Find the area of one (1) sheet:
Area
STEP 3
=
=
1.800
x
1.200
=
2.160m²
Divide the area of the wall by the area of one (1) sheet to find the number of sheets
required to clad the wall:
No.
= 15.120
x
2.160
=
7 sheets
Sheets joined on studs
Offcut used to
complete end of
top row of
sheets
End of top
row of
sheets
Fig. 83
covering
Sheets
wall
38
CARPENTRY - HOUSING
STEP 4
Calculate the number of cover straps required to cover all the joints:
Horizontal
=
1/ 6.3
Vertical
=
6/ 1.2 or 3/ 2.4
∴ allow 7/ 1800 x 1200 x 4.5mm sheets, 50 x 19mm cover straps – 1/ 6.3, 3/ 2.4
Example 2:
Calculate the number of 150 x 25 Rusticated weatherboards for a single wall 6300mm long x
2400mm high. The boards are to be random lengths fixed horizontally and finish flush with
both ends when:
•
•
•
•
10% wastage is allowed for cutting and joining on a stud;
Nominal or sawn size is 150 x 25mm;
Milled size is 140 x 20mm; and
Effective cover is 133mm.
2400
450
6300
Fig. 84 Single wall to be clad
Identify the height of the wall:
Height
Identify the effective cover of one (1) board:
Effective cover
=
133mm
25
STEP 2
= 2400mm
20
STEP 1
150
133
140
Fig. 85 Effective cover of a weatherboard
39
STEP 3
Divide the height of the wall by the effective cover of one (1) board to find the
number of boards required to cover the height of the wall:
No.
STEP 4
2400
÷
133
=
18.045 say 19 rows
Multiply the number of rows of boards by the length of the wall to calculate the lineal
metres of boards required to cover the wall:
Lin.m
STEP 5
=
=
19
x
6.300
=
119.700m
Multiply the lineal metres by itself plus 10% for wastage when cutting and joining:
Total
=
119.700
x
1.10 (amount plus 10%)
=
131.670m
∴Total
lineal metres of 150 x 25 Rusticated weatherboards = say, 132.0m
Height of wall
Waste ripped off last board
Waste
Staggered butt joins on studs
Fig. 86 Wall clad with weatherboards
Deductions for openings
Where the area of the opening in a wall is less than 1.0m², no deduction will be made.
Openings greater than 1.0m² should have sheet and board material deducted, using the same
method of calculation for wall coverage.
Example 3:
If the wall in Example 1 had a window 1200mm high x 1800mm wide, the area of the window
opening will be deducted from the total wall area before the total sheets are counted.
Area of window
=
1.200
x
2.100
=
2.520m²
Deduct window
=
15.120
-
2.520
=
12.600m²
∴ Sheets
=
12.600
÷
2.160
=
5.833 say 6 sheets
40
CARPENTRY - HOUSING
WORKED EXAMPLE FOR CLADDING QUANTITIES and COSTS
The following worked example provides details of how the quantities are arrived at and how
the individual materials are presented and costed, based
Example 1: Sheet Cladding
Calculate the quantity and cost of cladding material and accessories when:
The 2400mm high wall frames are to be clad with 4.5mm thick fibre cement sheets fixed
horizontally. The horizontal joints are covered with fibre cement ‘C’ moulding and the vertical
joints are covered with 50 x 19mm DAR timber cover mould. The external corners are covered
with a full height fibre cement 90° angle mould.
SPECIFICATION
MATERIAL
SIZE
COST
Fibre cement cladding
1800 x 1200 x 4.5mm thick sheets
$15.00/ sheet
Horizontal ‘C’ mould (FC)
2400 x 50 x 20mm thick
$0.60/ m
Vertical 90° corner mould (FC)
2400 x 50 x 50 x 6mm thick
$0.80/ m
DAR primed timber cover
mould
2400 x 50 x 19mm thick
$0.70/ m
DOOR OPENINGS
WINDOWS
D1 = 2110 x 900mm
Window
Height (mm)
Width (mm)
W1
900
1720
W2, W3
1250
1720
(1)
(2)
(4)
(3)
Fig. 87 Typical plan of a timber framed cottage
41
METHOD
Sheets -Take each wall separately, calculate the total surface area, deduct openings,
calculate the area of one (1) sheet, divide the wall area by the area of one
(1) sheet;
‘C’ mould -Calculate the total perimeter, deduct openings, divide by 2.4m lengths;
90° Corner mould -Count the number of corners, allow one length per corner;
DAR Cover mould -Count the number of vertical sheet joins per wall, allow one 1.2m length
per vertical sheet join, add lengths to order 2.4m lengths.
STEP 1
STEP 2
STEP 3
Start with wall (1) and calculate the area of each wall working around the outside in a
clockwise direction:
Area wall (1)
=
6.000
x
2.400
= 14.400m²
Area wall (2)
=
4.800
x
2.400
= 11.520m²
Area wall (3)
=
6.000
x
2.400
= 14.400m²
Area wall (4)
=
4.800
x
2.400
= 11.520m²
Calculate opening areas for each corresponding wall:
Wall (1) W2
=
1.250
x
1.720
= 2.150m²
Wall (2) W3
=
1.250
x
1.720
= 2.150m²
Wall (3) D 1
=
2.110
x
0.900
= 1.899m²
Wall (4) W1
=
0.900
x
1.720
= 1.548m²
Deduct the openings from the corresponding walls:
Wall (1)
= 14.400 -
2.150
= 12.250m²
Wall (2)
= 11.520 -
2.150
= 9.370m²
Wall (3)
= 14.400 -
1.899
= 12.501m²
Wall (4)
= 11.520 -
1.548
= 9.972m²
Divide each wall by the area of (1) sheet to find the total number of sheets required:
42
CARPENTRY - HOUSING
STEP 4 Calculate the area of one (1) sheet and divide it into each wall area to find the
number of sheets required for the whole cottage. Treating each wall separately
allows for easier calculation of accessory mouldings.
Area of (1)
sheet
=
1.800
Wall (1)
=
12.250
÷
2.160
= 5.671 say 6 sheets
Wall (2)
=
9.370
÷
2.160
Wall (3)
=
12.501
÷
2.160
Wall (4)
=
9.972
÷
2.160
∴ Total
of 1800
sheets
the
22 sheets
STEP 5
x
1.200
= 2.160m²
number
x 1200
to clad
cottage =
Calculate the number of lengths of ‘C’ mould to cover the horizontal sheet joins:
Perimeter
=
6.000 + 4.800 + 6.000 + 4.800
= 21.600m
=
1.720 + 1.720 + 1.720
= 5.160m
Deduct
openings greater than 1.0m:
Openings
Therefore
21.600 – 5.160
= 16.440m
Divide perimeter by 2.400m lengths to find the number of pieces required:
Number of
lengths
16.440 ÷ 2.400
=
= 6.850 say 7
∴ Total number of ‘C’ mould lengths to cover the horizontal joins = 7/ 2.4m
STEP 6
Calculate the number of lengths of 90° corner mould to cover the vertical sheet
external corners by counting the corners:
Number of
corners
=
4
∴ Total number of 90° corner mould lengths to cover the vertical corners = 4/ 2.4m
43
STEP 7 Calculate the DAR cover moulds required to cover the vertical sheet joins. Take
each wall separately allowing 1/ 1.2m length to cover the butt joint between sheets.
Allow one less than the number of sheets per wall:
Wall (1)
= 6
-
1
= 5/ 1.2
Wall (2)
= 5
-
1
= 4/ 1.2
Wall (3)
= 6
-
1
= 5/ 1.2
Wall (4)
= 5
-
1
= 4/ 1.2
TOTAL = 18/ 1.2
∴ Total number of DAR cover mould lengths to cover the vertical joints = 9/ 2.4m
COST SHEET
ITEM
SIZE
MATERIAL
LINEAL m
or No.
Cladding
1800 x 1200 x 4.5mm
Fibre cement
22
‘C’ mould
50 x 20mm
Fibre cement
7/ 2.4
90° mould
50 x 50 x 6mm
Fibre cement
DAR mould
50 x 19mm
Primed timber
TOTAL
LINEAL
RATE
$15.00
$330.00
16.8
$0.60
$10.08
4/ 2.4
9.6
$0.80
$7.68
9/ 2.4
21.6
$0.70
$15.12
TOTAL COST
44
COST
$ 362.88
CARPENTRY - HOUSING
Example 2: Weatherboard Cladding
Calculate the quantity and cost of cladding
material and accessories when:
The wall frames have an exposed surface of 2350mm and are to be clad with 25mm thick
primed Rusticated timber weatherboards fixed horizontally. The horizontal joints are to be butt
jointed and staggered and abut 50 x 25 corner battens at external corners. A total lineal length
of boards is to be ordered made up of random length boards.
SPECIFICATION
MATERIAL
Rusticated weather boards
(Cypress pine)
SIZE
150 x 25mm thick
(133 effective cover)
$4.20 /m
DAR Corner battens
(treated pine)
50 x 25mm thick
$1.25 /m
DOOR OPENINGS
COST
WINDOWS
D4 = 2110 x 900mm
Window
Height (mm)
Width (mm)
W1, W2
1200
1800
W3, W4
1200
1200
W5
2100
1800
(1)
(4)
(2)
(3)
Fig. 88 Typical plan of a timber framed cottage
45
METHOD
Weatherboards -Take each wall separately, divide the height of the wall by the effective
cover of one (1) board to find the number of rows, multiply the rows by the
length of each wall, deduct openings, allow 10% cutting and jointing waste;
Corner battens -Allow one (1) per external corner, equal to the height of the wall.
STEP 1
Divide the height of the wall by the effective cover of each board to calculate the
number of rows for each wall:
Number of
= 2.350 ÷ 0.133 = 17.669 say 18 rows
rows
STEP 2 Multiply the length of each wall by the number of rows to calculate the total lineal
metres:
Wall (1)
= 10.200 x
18
= 183.600m
Wall (2)
= 7.500
x
18
= 135.000m
Wall (3)
= 10.200 x
18
= 183.600m
Wall (4)
= 7.500
18
= 135.000m
x
TOTAL = 637.200m
STEP 3
Calculate deductions for openings:
W1, W2
W3, W4
= 1.200
÷
0.133
= 1.800
x
9
= 16.200m per window
=
16.2
x
2
= 32.400m
= 1.200
÷
0.133
= 1.200
x
9
= 10.800m per window
=
x
9
= 21.600m
10.8
= 9.023 say 9 rows
= 9.023 say 9 rows
46
CARPENTRY - HOUSING
W5
D4
= 2.100 ÷
0.133
= 1.800 x
15
= 2.110 ÷
0.133
= 0.900 x
15
TOTAL DEDUCTIONS
= 15.789 say 15 rows
= 27.000m
= 15.865 say 15 rows
= 13.500m
= 94.500m
STEP 4
Deduct openings from the total wall cladding:
∴ Total
of
Deductions
STEP 5
lineal metres
= 637.200 - 94.500 = 542.700m
Allow 10% waste for cutting and joining. Multiply the total by 1.10, which represents
the total plus 10%:
Add waste
= 542.700
x
1.10
= 596.970m say 597.0
weatherboards required to cover the walls = 597.0m
STEP 6
Calculate quantity of external corner battens, allowing (1) per corner:
No of battens
=
4 corners
∴ Total
external corner battens = 4/ 2.4m
= 4/ 2.4
number of
COST SHEET
ITEM
SIZE
MATERIAL
WeatherBoards
150 x 25mm
Cypress pine
Corner
battens
50 x 25mm
Treated pine
LINEAL m
or No.
4/ 2.4
TOTAL
LINEAL
RATE
COST
597
$4.20
$2,507.40
9.6
$1.25
$12.00
TOTAL COST
$ 2,519.40
47
GLOSSARY OF TERMS
Aesthetic - Refers to the pleasing appearance of an object or the finish of a product.
Colorbond™ - This is a trade name referring to an applied finish, which involves the
application of colour to metal sheet products, by baking several
individual layers, to form the protective finish.
Conite - This is a trade name, mainly used in Victoria, given to a process of
cladding finishing. It is basically the same as the tyrolean spatter finish
applied over fibre cement sheeting to provide a textured surface finish.
Crippling timber - This is a process, which involves the cutting, wedging or cleating of
timber framing to make it straight, where a spring occurs.
Deflection - This is the result of any member placed under load, which has bent. The
deflection is the amount the member has bent or bowed from its original
straight position.
Hybrid - This is a mixture or combination of two or more parts, which makes a
similar product.
Patent - This is a term used to describe a product which has had its design
registered with the Patents office. It is the original idea of a person or
persons, which cannot be copied without consent.
Permeable - This means any material, which is capable of being penetrated or passed
through. Permeable sarking, for example, will allow vapour or moisture
to pass through it, so it doesn’t sweat underneath.
Pliable - This is any material, which is easy to bend, is flexible or supple such as
thin sheeting material.
PVC - Literally means Polyvinyl chloride, which is a type of plastic available
in soft and hard forms used for various applications.
Staggered - This refers to the placement of solid bridging, noggings, trimmers,
sheets, etc. by offsetting every piece from the previous one, when placed
in a row or above oneanother.
Stucco - Originally it was a type of render finish made of sand, cement and lime
applied to the surface of masonry with a swirling textured finish. It is
also applied to the stucco-like pressed finish on some fibre cement
products used as cladding over timber frames.
Tyrolean - This is a rough plaster coating thrown or shot onto wall surfaces using a
spattering gun or ‘Tyrol’ gun.
48
CARPENTRY - HOUSING
FURTHER READING
BHP Building products, Port Kembla, NSW, freecall 1 800 641 417. (for further information)
CSR Ltd, Villawood, NSW, call 1300 369 448. (for further information)
James Hardie Building products, Rosehill, NSW, freecall helpline 1 800 021 321. (for further
information)
Simpson, Charles & Barry Hodgson, 1995, Building a house – framing practices, Macmillan
Education Australia, South Melbourne.
Staines, A., Reprinted 1987, Owner Builders & Renovator, Pinedale Press, Caloundra, Qld.
Staines, A., Reprinted 1988, The Australian Owner Builders Manual, Pinedale Press,
Caloundra, Qld.
Teachers of Building NSW, 1996 Reprinted 1997, 1998, Second Edition 1999, Basic Building
and Construction Skills, Addison Wesley Longman Australia Pty Ltd, South Melbourne.
Ward-Harvey K., 1984, Fundamental Building Materials, Sakoga Pty Ltd, Mosman NSW.
49

EXTERIOR CLADDING / FINISHING

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