Cost of CFC product vs plasterboard installation

Hello,

We are renovating our house and initially had plasterboard going on all walls. Since the contract was signed we decided to get Hardiegroove wallboard installed to one of the walls in lieu of plasterboard, which is 16.47m2 in total. After the work has been completed the builder has advised us this change cost $1778 on top of what it would have cost us to install plasterboard, which I find hard to believe. They stated that Hardiegroove is much more labour intense and requires more screws (fixing every 200 mm, plasterboard every 300mm). Does anyone of you know how much time would take to install and flush plasterboard for that area vs Hardiegroove? I calculated Hardiegroove material cost to be approx $51/m2. There is one door, 1 light switch, 3 GPOs, sheet height matches the ceiling height and only one sheet had to be cut for the doorway.
Thanks in advance!

Hey bc89
You should have worked out a price estimate prior and queried it against the builders quote variation
Here
Hardiegroove lining @ $120/sheet -> $120/(2.7m*1.2m) = $37/m2 - $9m2 (gyprock) = 28/m2
Material 17m2 wall x $28m2 = $476 + screws
Labour extra over gyprock fixing say an extra half day = $300
Balance Builders profit?
Cheers
Chris

Hi Chris,

Thank you for your reply. Yes, I agree - I should have requested a price estimate prior to installation. We are in NT and everything up here costs much more. Based on the local prices I calculated that the builder charged us approx. $160 per hour.
Do you know roughly how long it would have taken to plaster, flush and sand the same wall?

Allow 6hrs for 10m2 plasterboard
1st Cross check
6hrs x $35/hr = $210/10m2 or $21m2
2nd cross check
Plasterboard Fixing Cost per m2 Australia
Cheers
Chris

Thank you!

Hi Chris,

I have spoken to our builder who claims that it would have taken him 2 hours to plaster that wall (6100 long x 2700 high) and based on my calculations he claims it took 10 hours to install hardiegroove. I am more certain now that they are trying to recover their profit as there is another variation item that does not add up to me. Given that there was no fee estimate given, would I be in a position to dispute those fees? Or does that mean it's an open chequebook for them? We signed a MBA contract and it does not really tell me much.

Thanks,

BC

Underestimating the credits and over estimating the add on variations is called price gouging
Anywhere else consumer protection would be all over them
Consumer Affairs Price rip offs
Unfortunately, The MBA & HIA Contract favours the Builder and its Buyer Beware .
Unless battlers and punters call out this antisocial behaviour things won't change
Cheers
Chris

Chris, thanks for your advice.