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How to add a subfloor ground moisture barrier?

Finding My Feet

How to add a subfloor ground moisture barrier?


I want to place black plastic polythene under my subfloor. The plastic needs to go on top of the ground to keep the moisture from effecting hardwood floors that we are planning to install. I have no idea if there are companies in Sydney that are able to do the installation? I've started laying one row but the space is quite tight and probably needs someone a bit smaller that has the patience to do the work. Any ideas how I can 'google' and find tradies / companies that can do the work? 


Link to a site in New Zealand that speaks to the works I need to do:


Thanks so much!

Bunnings Team Member
Bunnings Team Member

Re: How to add a subfloor ground moisture barrier?

Hi @Chrismichael,


Welcome to the Bunnings Workshop community, it is great to have you with us.


The three types of businesses that I can think might be able to assist you with this kind of job are handymen, landscapers and water proofers.


While none of these specialise in this exact style of project, I'm sure they would undertake similar work and would have the knowhow to be able to help.


You might like to use a service like Hipages or Airtasker to search for someone to do this job. I would advise taking some photos and giving as much detail as possible to ensure someone answers as quickly as possible.


If you wanted to try and take on the job yourself, I'd suggest getting GRUNT 2 x 100m Black 70um Multi Use Plastic Film, Grunt Builders Film Tape, and a headlamp.


If you have any other questions, please feel free to get in touch.




Re: How to add a subfloor ground moisture barrier?

Thanks Jacob for your suggestion,


I reached out to a few companies and heard back from one that specialises in waterproofing and subfloor ventilation. The moisture barrier is something they have installed in the past and are familiar with, just not something they advertise.


Thanks for leading me in the right direction!



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