Ground moisture barrier installation

[divxmaster]

Hi,
where about is a good place to get the polyethene? I'm having a house moved on to a site, so I can put it down just after they put in the new piles.

Cheers,
Mike.

[simongu]

I got mine from Placemakers as they had it on special, but either them or Bunnings / Mitre10 had it at similar prices. Just be careful to get the right spec, you cant just look at the thickness have to get the right flow rating

[semaj_nil]

The latest quote I got is $800 incl GST for 100sqm, which issues me a more proper cert done by professionals, I have been crawling under the house a few times and weren't pleasant experience. Also the $800 spend will counter the tax I pay from the rent, so at the end of the day I am only spending ~$500 to get it done properly and without all the mess.

[divxmaster]

yes, $500 is fine, i'd pay that. @simongu, do you have some info on the flow ratings?

[simongu]

From the HH Regs: Clause 28.2 : "Barrier made of appropriate materials and installed as per Section 8 of NZS 4246:2016", which in turn defines "polythene film with thickness >= 0.25mm AND a vapour flow resistance of at least 50 MN s/g (Mega- Newton seconds per gram)". You dont need to know what that means, it is generally stated on the product specs e.g. this one from placies (which b.t.w. I wouldnt get as only 1m wide, get a 2m wide one so goes pile to pile):

https://www.placemakers.co.nz/products/building-materials/building-wraps-flashing-tapes-dpc/agpac/agpac-250-micron-4-25m-heavy-duty-polythene-black/

[semaj_nil]

Heh, I asked them to start the work now they say $800 does not include GST.

[jimO]

Heh, I asked them to start the work now they say $800 does not include GST.

did the quote say excluding gst?

[semaj_nil]

The quote(email) said $800 including gst, but now they are saying it's incorrect.

Previously:

> Our price for a 100sqm ground moisture barrier is $800 including GST. The estimate price is subject to the condition and height of the underfloor.

Today:

> $920 including GST is the price. The prices given to you are all estimated prices. A formal quote will be sent to you by our sales team upon conducting a site visit.

[donna]

Closer to the deadline for compliance expect the fee to be 300 percent more.

[semaj_nil]

Closer to the deadline for compliance expect the fee to be 300 percent more.

The time between the 2 reponses was just a month apart...

[mrsaneperson]

Their is an exemption to installing this if it's not reasonably practical for a professional installer to carry out the work or would cause a greater than normal risk to health and safety. To quote from the government tenancy site.

In many cases this could be an arguable defence to avoid installing it, where the area is used for storage of items, that are most often than not bulky and heavy. The plastic moisture barrier if installed would tend to rip when these items are removed accessed or other items are needed to be stored in the area. Most home owners utilise this space for storing timber, metal, engine parts and other general stuff. Seems very impractical especially so in these tight crawl spaces.

[donna]

We checked out a rental on the weekend. The moisture barrier had been done just before we bought it in 2015 and we thought it might so-so condition - but we were wrong. It's a pass. The property does have wooden window frames though so there will be gaps more than 3 mm or whatever it is - so that might be more challenging.

Replacing the windows would be very expensive and in my experience when I've put in the draft stop - it can create a larger gap. esp. with those windows that swing out and the window latch butterfly nut doesn't completely close.

cheers,

Donna

[mrsaneperson]

I've always replaced wooden windows with Aluminum ones when the time came, rather than repairing them. This way you can also upgrade to a double glazed installation which should add something onto the property and help immensely with heat retention. Another upside is they are maintenance free.

[jimO]

I've always replaced wooden windows with Aluminum ones when the time came, rather than repairing them. This way you can also upgrade to a double glazed installation which should add something onto the property and help immensely with heat retention. Another upside is they are maintenance free.

we have just ripped all the 20 year old aluminium single glazed windows out and replaced them with siberian larch tilt and turn windows

[donna]

Wow that sounds expensive JimO. This is in your house or a rental?

cheers
Donna