00133 Boral4Builders no4

8/10/2019 00133 Boral4Builders no4

1/12

A Quarterly Publication by Boral Plasterboard Spring Edition 2000

Targetingthe Issues

Boralfor

BuildersFollowingS

pecific

ation

s

Manufacturers

Guarantees& W

arrantie

s

Workmans

hip

HiddenCost


2/12

2

About This Edition

Welcome to the third edition of

Boral Plasterboards Boral for

Builders Magazine.

Once again we focus on the

real issues facing tradespeople

in the plaster industry.

In particular this issue, we

target back-blocking, effects

of lighting on finished

plasterboard walls & ceilings,

Expansion and Control Joints

and warranty problems

associated with using mix and

match products. And as with

every issue, the Bureau of

Statistics have provided us

with the housing and

residential building approvals

for the June Quarter 2000.

The Editor.

Boral for Builders Magazine

Boral Plasterboard

Marketing Services

Department

676 Lorimer Street

Port Melbourne Vic 3207

Contents

The Back-blocking Story ... 2,3

Getting the Right Angle 4,5on Lighting

Expansion or Control J oints 6 & 7

Building activity statistics 8, 9

The Mix & Match Trap 10, 11

TecASSIST 12

Some years have passed

now since the South

Australian experience of

peaking, joint cracking and

joint distortion that affected

many homes. In the meet-

ings that followed, isolating

the exact cause proved once

again to be elusive due to

the many variables in the

building process.

On the positive side however, the joint

sponsored investigation conducted at

Monash University that followed and

the inclusion of back-blocking into

Australian standards and plasterboard

manufacturers specification must surely

be recognised as one of the mostsignificant contributions toward both

maintenance reduction and the overall

presentation of plasterboard seen in the

industry for a long time.

In some quarters, slow recognition

of the benefits has been governed

somewhat by the belief that anything

that impacts on the final selling price

will reduce competitiveness in the

market place or by resistance at times

from trades people claiming they have

never experienced ceiling problems.

Are they serious??

It is of interest to find that decisions

regarding a few dollars for extras thatcan add significantly to someones

prestige home receive little

consideration (particularly if they cant

be seen).

My experience has shown regular

comments from frustrated owners who

would have gladly paid any extra costs

for back-blocking if only they had been

given a choice rather than be faced with

the dust and disruption that follows any

rectification program carried out overtheir new carpet and furnishings.

As plasterboard manufacturers, we

have witnessed and are happy to

report a noticeable decrease in costly

maintenance issues relating to ceiling

problems as a result of the

back-blockingsystem.

Many plasterers and builders now

implement back-blocking of ceiling

joints as part of their normal practice

and jobs are priced accordingly.

Unfortunately some confusion still

exists in the industry in relation to:

a)The exact requirements of thestandard.

b) Whether it is a manufacturersspecification or not.

c) Is back-blocking required with13mm ceilings?

d) Is back-blocking required whenbattens are used?

The Back-blocking Story...

Inverted peaking due to the ageingprocess.


3/12

3

A. Extract from Australian/New Zealand Standard AS/NZS 2589.1:19977.7.2.4 Recessed joints in ceilings All recessed joints on a ceiling shall be back-blocked in any area

containing three or more recessed joints.7.7.3 Back blocking procedure.

7.7.3.1 Ceiling recessed edge joints the procedure shall be as follows:

a) Cut back-blocks at least 200mm wide and long enough to fit loosely

between the framing members.

b) Apply plaster based setting type adhesive/cement to back-blocks over

the full face of the back-block. A notched spreader to give 6mm x 6mm

beads at approximately 20mm centres at right angle to the joint would

be satisfactory.

B. Back-blocking does form part of manufacturers specifications and isrecommended by leading industry authorities.

C.The standard makes no differentiation between board types or thickness;the reference is for all ceilings to be back-blocked.

D. Battens either metal or timber can be no Substitute for back-blockingdue to the separate functions they are expected to perform. (Battened

ceilings must be back-blocked.)

The requirements for back-blocking make no differentiation between the various

applications or building systems, so it should be noted that any warranties or

guarantees from your plasterboard manufacturer will in all probability revolve

around compliance to these recommendations, should problems such as joint

distortion, peaking joints or cracking occur.

Failure to comply may render your plasterer liable for any associated cost relating

to maintenance and/or rectification caused by suspected jointing defects.

Our views on the merits of back-blocking remain unchanged despite a trend in

the industry to exclude anything that remains unseen or contributes nothing to

the overall short-term appearance. Particularly if there is an added cost similar

to other systems such as sisalation, paint sealers, ventilation etc. Have you ever

wondered why a large ceiling that looked perfectly flat at handover was almost

an embarrassment hen you are called back some time later. At this point we

may have blamed settlement, movement etc. and over time this explanation for

the deterioration has been accepted as a foregone conclusion.

We now know that ceilings that have been back-blocked correctly will perform

satisfactorily for the life of the building and eliminate joint distortion, cracking

peaking joints etc.

Cheap insurance for any slight additional cost.

" P las terboa rd pe aking ha s proba bly been pa rt of the housing industry for a long time

however modern design techniques particularly the switch from relatively small rooms to

ope n-pla n living a nd the use of lights fitted flush w ith the c eiling te nd to a cc entuate the

pea king" sa ys S hane McC a rtin, HIA National Tec hnica l Direc tor.

" Although the sheets a re fla t when they a re la id, a ny growth or creep by the pla sterboa rd o r

its suppo rting structure ma y result in distress of the p la ste rboa rd joints, res ulting in reverse

pea king or cra cking if the joint is p ulled a pa rt or pea king if it is fo rced tog ethe r. The d is tress

a t the joint ma y be s ma ll but is highlighted a s s ha do w b y the flush-fitted lights ."The HIA tog ethe r w ith Vic torias B uilding C ontrol Co mmiss ion, plas terbo a rd manufac turers

a nd the timbe r indus try are funding a $30,000 res ea rch p rojec t a imed a t elimina ting the

problem of ceiling joint cracks and peaking commonly known as plasterboard peaking.

The results o f the res ea rch will hop efully ena ble the indus try and the HIA to w ork tog ethe r

to d etermine a so lution to this problem.

The Facts are:

Rafter or joist

Back-block

Temporary battensBoral Plasterboardsheet

Temporary nailing

Cornice adhesive

Packing strip

Back-blocks in place

Boral Plasterboard ceiling

Ceiling joist or bottom chordof roof truss

Wall

Back-block, from pieces ofBoral Plasterboardsheet 200mm wideminimum, glued withBoral PlasterboardCornice Adhesive

Roof truss

Boral Plasterboardceiling

Cross section through back-block.

View of back-blocking in ceilingfrom below.

View of back-blocking in ceilingfrom above.


4/12

4

Much has now been said about the effects

of lighting on finished pla ste r surfa ce s.

Despite our best efforts with education,

literature and illustration, there are still many

hurdles to overcome pa rticularly w hen

attempting to demonstrate to a less than

happy owner (one w ho ha s just viewed for

the first t ime the ceiling s of his/her new

home at night) the circumstance behind this

unwanted phenomenon occurring in their

residence.

When considering the type of finish

required from plasterboard, it is

important to understand how the

overall appearance is to be affected

by glancing light.

Getting the Right Angle on Lighting

We are aware that the common requirement is for a

flat blemish- free surface. However, despite every-

ones best intentions that is not always possible to

achieve.

As industry professionals, we are faced with a constant challenge to give a better

understand ing to des igners and builders so that they may indica te to the end user the

standard that can reasonably be expected from the choice of materials and design

w ithin their nomina ted bud ge t.

Unfortunately there is still a gap between owners expectations of plasterboard finishes

and what is realistically attainable, particularly when consideration is given to the materials,

substrates a nd s ystems that a re a vailab le.

Plasterboard ceiling under glancing light conditions.


5/12

5

At Boral Plasterboard we stronglyrecommend:

1. The ins ta lla tion of low co s t pla s ticsha des over any ba re b ulb in order to

avoid glancing light on plasterboard

ceilings.

2. Avoidance of fluorescent tubes unlessthey ca n be insta lled a t right a ngles to

any plastered joints or recessed into the

ceiling.

3. Adjustment of any spotlights so as toa void g la ncing light o n ce ilings or wa lls.

These a ctions in a ll prob a bility will ma ke the difference b etw een a n ow ners a cc epta nce o r

rejection of the appearance of the ceilings or walls in their new residence and may avoid the

obvious requests for rework to be carried out when we know it would not provide the total

solution.

When cost is not a governing factor, the performance, quality and appearance of all interior

lining material can improve considerably, as opposed to low budget construction, that in most

ca se s w ill pla y a ma jor role in de termining the overa ll qua lity a nd p res enta tion o f finish.

How ever difficulties still arise whe n explaining the likely c ons eq uence to s omeo ne w ith the

belief that c os t doe s not impa ct o n q uality.

The same ceiling under different lightingconditions when viewed from another angle.

Todays contemporary designs pose many

problems for plasterers, particularly when

these designs include large ceiling areasand window openings. Anyone who has

ever built opposite water canal estates,

swimming pools etc. will testify to the

dramatic change in appearance that can be

caused by light reflections.

There is no doubt that todays competitive market

presents an enormous challenge for both builder and

plasterer in attempting to provide an acceptable finish

for a competitive price. An intelligent approach to

lighting will assist.


6/12

6

With tod a ys residence s be co ming larger a nd mo re c omplex in their des ign, the role the

control joint plays in reducing maintenance increases dramatically.

P la cement of these joints in any pa rticular situa tion ma y not a lwa ys g a in insta nt ac cepta nce

or approval from an owner who has vision of an unbroken ceiling or wall line and a lack of

understanding regarding building movement.

Of particular concern are:

* stairwell areas in high-set homes

* where large ceiling areas connect to hallways

* where ceilings intersect through openings with no heads.

Expansion or Control Joints

From a homeowners perspective, why install anything that

co mpens a tes for building move ment? As a fter all he/she never

w a nted moveme nt in their building in the first plac e !

There is a need for more educ a tion in this a rea so ow ners ca n

ga in a bette r understa nding of the role c ontrol joints pla y.

To a void c onfusion a nd a ss ist w ith ac ce pta nce , ide ntifica tion of

a ny areas of suspec t movement could b e clearly marked on a ny

pla ns or draw ings at the des ign s tag e. The spec ifica tion of c ontrol

joints deta iled on the pla n w ill ensure they a re included a nd

respo nsibilities a re then ta ken for exact loca tions a s oppos ed to

the hit and miss approach currently in place.

Plasterboard installation recommendations for control

joints relate only to movement that may occur in the

plasterboard itself and its supporting frame, they do

not cover any significant stresses imposed by structuralmovement in any particular building.

Floor joist

Control Joint RondoComponent P35 Furring channel Masonry wall

Control J oint RondoComponent P35

Masonry adhesive daubs

Note: Boral Plasterboards fixing specification for expansion joints. The provision of a proper backgroundwill ensure their correct installation.


7/12

7

Photos 1. 2. 3. & 4. - Ceilings constructed with expansion or control joints.Photos 5. 6. 7. - Cracking or stress fractures due to structural movement.

2 3

65 7

4

1


8/12

8Building approvals: Number of houses & other residential

buildings approved by Statistical Division (SD)

J une Quarters 1999 & 2000Prepared for Boral Plasterboard, 16 October 2000

Source: Australian Bureau of Statistics

NSW Dwelling Approvals Dwelling Approvals VarianceJune Quarter 1999 June Quarter 2000

Total Total other Total Total Total other Total Total Total other Totalhouses residential residential houses residential residential houses residential residential

Regions building building

Sydney 4120 4855 8975 3354 3783 7137 -18.59 -22.08 -20.48

Hunter 889 484 1373 748 389 1137 -15.86 -19.63 -17.19

Illawarra 610 191 801 406 58 464 -33.44 -69.63 -42.07

Richmond-Tweed 329 86 415 186 48 234 -43.47 -44.19 -43.61

Mi d-North Coast 461 206 667 442 204 646 -4.12 -0.97 -3.15

Northern 131 45 176 120 29 149 -8.40 -35.56 -15.34

North Western 110 12 122 90 7 97 -18.18 -41.67 -20.49

Central West 192 46 238 204 43 247 6.25 -6.52 3.78

South Eastern 272 58 330 330 50 380 21.32 -13.79 15.15

Murrumbidgee 156 17 173 157 17 174 0.64 0.00 0.58

Murray 175 19 194 142 46 188 -18.86 142.11 -3.09

Far West 3 0 3 2 0 2 -33.33 0.00 -33.33

New South Wales 7448 6019 13467 6181 4674 10855 -17.01 -22.35 -19.40

VIC Dwel ling Approvals Dwel ling Approvals VarianceJune Quarter 1999 June Quarter 2000



Melbourne 5505 2376 7881 5454 2649 8103 -0.93 11.49 2.82

Barwon 613 103 716 526 86 612 -14.19 -16.50 -14.53

Western District 89 4 93 81 4 85 -8.99 0.00 -8.60

Central Highlands 233 8 241 210 6 216 -9.87 -25.00 -10.37

Wimmera 41 0 41 45 0 45 9.76 0.00 9.76

Mallee 130 0 130 104 8 112 -20.00 0.00 -13.85

Loddon 296 8 304 309 22 331 4.39 175.00 8.88

Goulburn 341 2 343 326 17 343 -4.40 750.00 0.00

Ovens-Murray 112 6 118 114 45 159 1.79 650.00 34.75

East Gippsland 99 4 103 95 6 101 -4.04 50.00 -1.94

Gippsland 309 12 321 304 17 321 -1.62 41.67 0.00

Victoria 7768 2523 10291 7568 2860 10428 -2. 57 13. 36 1. 33

QLD Dwel ling Approvals Dwel ling Approvals VarianceJune Quarter 1999 June Quarter 2000



Brisbane 2397 806 3203 2291 1258 3549 -4.42 56.08 10.80

Moreton 1588 942 2530 1557 1401 2958 -1.95 48.73 16.92

Wide Bay-Burnett 358 35 393 333 38 371 -6.98 8.57 -5.60

Darling Downs 242 23 265 235 27 262 -2.89 17.39 -1.13

South West 10 0 10 16 11 27 60.00 0.00 170.00

Fitzroy 157 18 175 181 29 210 15.29 61.11 20.00

Central West 4 0 4 6 0 6 50.00 0.00 50.00

Mackay 236 48 284 137 163 300 -41.95 239.58 5.63

Northern 283 54 337 272 46 318 -3.89 -14.81 -5.64

Far North 290 81 371 238 39 277 -17.93 -51.85 -25.34

North West 16 0 16 16 8 24 0.00 0.00 50.00

Queensland 5581 2007 7588 5282 3020 8302 -5.36 50.47 9.41


9/12

SA Dwel ling Approvals Dwel ling Approvals VarianceJune Quarter 1999 June Quarter 2000



Adelaide 1176 260 1436 1097 299 1396 -6.72 15.00 -2.79

Outer Adelaide 298 6 304 357 5 362 19.80 -16.67 19.08

Yorke & Lower North 94 7 101 70 0 70 -25.53 -100.00 -30.69

M urray Lands 86 4 90 69 0 69 -19.77 -100.00 -23.33South East 73 2 75 48 22 70 -34.25 1000.00 -6.67

Eyre 30 8 38 54 4 58 80.00 -50.00 52.63

Northern 44 8 52 19 0 19 -56.82 -100.00 -63.46

South Australia 1801 295 2096 1714 330 2044 -4.83 11.86 -2.48

WA Dwel ling Approvals Dwel ling Approvals VarianceJune Quarter 1999 June Quarter 2000



Perth 3338 869 4207 2506 1000 3506 -24.93 15.07 -16.66

South West 923 131 1054 566 98 664 -38.68 -25.19 -37.00Lower Great Southern 118 9 127 132 19 151 11.86 111.11 18.90

Upper Great Southern 46 8 54 38 3 41 -17.39 -62.50 -24.07

Midlands 148 8 156 147 18 165 -0.68 125.00 5.77

South Eastern 118 34 152 66 47 113 -44.07 38.24 -25.66

Central 124 13 137 85 23 108 -31.45 76.92 -21.17

Pilbara 48 40 88 24 0 24 -50.00 -100.00 -72.73

Kimberley 45 4 49 122 4 126 171.11 0.00 157.14

Western Australia 4908 1116 6024 3686 1212 4898 -24.90 8.60 -18.69

TAS Dwel ling Approvals Dwel ling Approvals VarianceJune Quarter 1999 June Quarter 2000



Greater Hobart 98 16 114 156 76 232 59.18 375.00 103.51

Southern 37 0 37 34 2 36 -8.11 0.00 -2.70

Northern 92 5 97 104 9 113 13.04 80.00 16.49

Mersey-Lyell 55 6 61 71 7 78 29.09 16.67 27.87

Tasmania 282 27 309 365 94 459 29.43 248.15 48.54

NT Dwel ling Approvals Dwel ling Approvals VarianceJune Quarter 1999 June Quarter 2000



Darwin 190 163 353 68 158 226 -64.21 -3.07 -35.98

NT- Bal 160 16 176 102 5 107 -36.25 -68.75 -39.20

Northern Territory 350 179 529 170 163 333 -51.43 -8.94 -37.05

ACT Dwel ling Approvals Dwel ling Approvals VarianceJune Quarter 1999 June Quarter 2000

Total Total other Total Total Total other Total Total Total other Total

houses residential residential houses residential residential houses residential residentialRegions building building

Canberra 343 163 506 347 190 537 1.17 16.56 6.13

ACT - Bal 0 0 0 0 0 0 0.00 0.00 0.00

ACT 343 163 506 347 190 537 1.17 16.56 6.13

Commonwealth of Australia, 2000

9


10/12

nnovative H eres an inn ovat ive s ystem from B oral Plasterbo ard thatp rovid es so lut ion s for p arty w alls in attac he d d w elling s.PartiWALL by Boral is essentially a timber frame twin wall

system, that includes 25mm fire-resistant plasterboardpanels within the wall cavity. This wall system has beendesigned to provide maximum flexibility for the designer and

builder, both in construction and performance.

PartiWALL is a smart design that permits the inclusion ofservice penetrations, such as switches, power points, light

fittings and pipes within the partition. The penetrations will notbreach the fire resistant elements or compromise the fire rating.

The inclusion of Borals 10mm or 13mm SoundSTOPplasterboard adds another dimension with acoustic ratings of upto and exceeding the STC 50 specified by the BCA.

Furthermore...PartiWALL was developed to suit the normal pattern of

construction and following trades. The internal fire-resistantplasterboard panels are placed in position between lightweight steel channels in

an assembly- like fashion - no plasterboard jointing or finishing is required. This jobsequence is carried out during the normal wall framing stage. The internal faces of the wall frame are then lined andfinished later with the preferred wall and ceiling linings.

Check the many benefits Boral PartiWALL provides:

Super high acoustic performance with up to Rw=56dB (STC 54);System provides fire rating of FRL60/60/60;Permits the inclusion of services and penetrations;Plenty of room to accommodate plumbing pipes, waste pipes, power points, light switches and cables - no special

fire protection of penetrations required;

Assembly type construction permits installation by carpenters at frame stage - no plastering trades required;Internal faces lined and finished as per normal finishing sequence; and

Cost effective and fast to construct. Outperforms masonry and concrete party walls for speed of construction,acoustic performance and flexible construction.

Acoustic Performance Table for PartiWALL System

Insulation PartiWALL 1 PartiWALL 2 PartiWALL 3

10mm Standard Plasterboard 10mm SoundSTOP 13mm SoundSTOP

No Insulation Rw=43dB STC=43 Rw=45dB STC=45 Rw=46dB STC=46

Insulation One Side Rw=49dB STC=48 Rw=51dB STC=50 Rw=52dB STC=51

Insulation Both Sides Rw=53dB STC=51 Rw=55dB STC=53 Rw=56dB STC=54

To find out how Boral PartiWALL provides solutions for party walls in attached dwellings:

Fill in the coupon below and fax it to: 03 9645 1707

Or Mail to: Marketing Services Department, Boral Plasterboard

Locked Bag 3, Port Melbourne, Vic 3207 Australia

Name ..........................................................................................................................................

Address ..................................................................................................................................................................................................

.............................................................................................................................................................. Postcode ................................

Telephone........................................................................................ Facsimile ........................................................................................Email address ........................................................................................................................................................................................

Distributor Address

Home buyer

DIY renovator

Architect/ Interior Designer

Draftsperson

Builder

Plastering Contractor

Indicate if you would like followup:

Sales Representative to call

Pricing Information

Technical Assistance

Store Locations

Am planning a project(approx. value$...................................)

Location .............................

P

artiWALL

PartiWAL

L


11/12

Should you require any more information on this or other

issues targeted in this edition of Boral for Builders,

please call:

Jim Browning(Brisbane) on 07 3215 2237

11

Did you know "The Mix and Match Trap" can void warranties?

In todays competitive environment and with the emphasis on cost before quality, there are always con-

stant pressures to save a dollar when and where you can. Its human nature isnt it and one may well ask

"wheres the problem?"

Well as we have recently found as a result of a major

paint issue in Queensland, the problem arises when

the system fails and manufacturers warranties can

not be supplied due to a mix and match of products.Now normally these products may only be accessory

items like tapes, adhesives, nails and screws etc.

purchased for the saving of a few dollars or less per

job.

The Mix & Match Trap

As more and more subcontractors become responsible for the supply and

purchase of their own a ccessories, this risk increases dram atically wi th

the main areas of concern being overlapping or mixing of manufacturers

products, paints, plasters and adhesives etc. and the stretching ofspecifications when referencing recommended usage.

Rectification responsibilities depend on adherence to thespecification

and the following of the total system; substitution of any particular

non-recognised products may not be worth the perceived savings should

problems occur.

Remember - gua ra ntees a nd w arranties a re tested to the limit when the q uestion of " whopays?" arises.

Plasterboard manufacturers design their products for specific purposes and compatibility;

they a re s cientifica lly formula ted for their nomina ted uses w ith s trict instructions iss ued

a cc ording to b est prac tice a nd proper a pplica tion.

Not recommended

+


12/12

2

The SeviceBased at the Boral Plasterboard Port Melbourne site, the service provides advice and technical assistance

to builders, architects, contractors, distributors, engineers, regulators and home owners throughout

Australia.

To date TecASSIST has handled some 16,000 technical enquiries, helping to build major and minor

projects across Australia and Asia.

And weve had em all! Everywhere, everyone, everything.

From Hobart to Cape York, Darwin to Wollongong, Broome to Newcastle, England to Fiji, Colombia to

Sweden, New Zealand to the United States

Fire Inspectors to Architects, DIYers to Contractors, Builders to Sculptors

Offices to Schools, Bungalows to Brothels, Cinemas to Navy ships, Airports to TV shows.

The teamThe TecASSIST Team represents over 100 years of

practical and professional experience and a coverage

of professions ranging from architecture to engineer-

ing, building to design, drafting to IT and trades tobusiness management.

Danny Docherty and Bernie Shalekoff

When in doubt, ask!Telephone: 1800 811 222

Facsimile: 03 9645 1812

Email: [email protected]

Sales Offices

QLD 733 Nudgee Rd Northgate 4013 Telephone (07) 3215 2244 Facsimile (07) 3215 2299

NSW Thackeray St Camellia 2142 Telephone (02) 9638 0571 Facsimile (02) 9638 5557

SA 119 - 121 Bedford St Gillman 5013 Telephone (08) 8240 8888 Facsimile (08) 8341 1004

VIC 676 Lorimer St Port Melbourne 3207 Telephone (03) 9214 2138 Facsimile (03) 9646 1912

WA 12 Hoskins Rd Landsdale 6065 Telephone (08) 9400 2666 Facsimile (08) 9302 1133

ACT 7 Barrier St Fyshwich 2609 Telephone (02) 9280 4243 Facsimile (02) 9280 5816

TAS 93 Albert Rd Moonah 7009 Telephone (03) 6278 9966 Facsimile (03) 6278 9865

NT Crn Coonawarra Rd & Mataram St Winnellie 0820 Telephone (08) 8984 4484 Facsimile (08) 8984 3778

Export Dept 676 Lorimer St Port Melbourne 3207 Telephone (03) 9214 2138 Facsimile (03) 9646 1109

00133 Boral4Builders no4

Documents