# Forum Home Renovation Sub Flooring  Insulation under floor in 2013.  Termites & Vermin?

## HouseOB

Hi all, 
Just wondering what is the current common method of sub-floor insulation in a suspended floor these days?  There are quite a few posts about it here but most seem to be quite a few years old. 
With our extension we have requirements for sub-floor insulation, which I beleive is R2.8 in Melbourne (please correct me if this is wrong!).  Given that we have easy access (400mm + under plus full access above before the floor is put on), I was thinking of having poly batts strapped in under timber floor boards, with plastic packing strap or something similar. 
Questions
1. Is there a better product that I should be looking into that is also cost effective? 
2. What method are people using to hold them in these days? 
3. Doesn't having sub-floor insulation make termite inspection more difficult?  Previously you could see the floorboards making termites much easier to see, and also providing less hiding spots for vermin.  Having said that, since insulation is a requirement it's not like I have a choice.  So is there any product that is better against termites & vermin? (I guess with strapped batts, at least you can move them to inspect). 
Thanks!

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## r3nov8or

I used these Concertina FOIL BATTS - foil insulation - main page  
There are also polystyrene boards being advertised on TV at the moment

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## Cecile

> There are also polystyrene boards being advertised on TV at the moment

  They are called "Expol" Home  They were used under the floor in our bathroom renovation and do a really good job of maintaining the heat in the tiled floor (underfloor electric.)  Here's a page with a price on it but I have no idea if it's accurate.  Expol UnderFloor Insulation 410mm 
Foilboard is also a good product, rigid polystyrene boards.  We have it installed in some of our walls.  Foilboard® Insulated Panels - Polystyrene, Foam, Thermal, Structural, Insulation Board

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## HouseOB

Hmm, I'm sure something I read said Melbourne required R2.8 under floor, the Expol is only 1.4.  Maybe the 2.8R was recommended but not the minimum required? 
Expol looks okay but seems to be about twice the price of polyester batts, and a lower R rating? 
Also while the new part will have equal spacings, some of the existing house is all over the place =/

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## johnc

Besides Expol there is also a product called masterfloor, that can be obtained in two thicknesses. you can also get a roll out batt type product that gives continous runs. Go down to your local hardware and find out what is available there is quite a few options out there.

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## r3nov8or

> Hmm, I'm sure something I read said Melbourne required R2.8 under floor...

  The concertina foil batts I linked are rated R3.0. Works purely on creating a still air gap and reflecting radiant heat. It's all there on the site. Where our extension begins you can place a foot on each of the new insulated and the original non-insulated floor and the batts definitely make a difference. 
Please don't discount them because they are not big and bulky. And you can carry a whole house load in your back seat - try that with bulk batts.

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## HouseOB

> The concertina foil batts I linked are rated R3.0.

  I'll look into them a bit more, they seem pretty pricey compared to batts though?  Where did you buy them from?

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## r3nov8or

> I'll look into them a bit more, they seem pretty pricey compared to batts though?  Where did you buy them from?

  For the extension 10 years ago I think I got them from a mob in Moolap (eastern Geelong) but I have seen them recently at Belmont Timber & Hardware (southern Geelong).  
They aren't cheap but are double the R value of the other you mentioned. Are they double the cost? (Been too long so I don't know)

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## Floop

> With our extension we have requirements for sub-floor insulation, which I beleive is R2.8 in Melbourne (please correct me if this is wrong!).

  From memory Melbourne has a minimum R1-1.5 requirement for an enclosed sub-floor, and R2-2.5 for unenclosed.  Chances are you'd be covered using only R1-1.5, heat loss through the floor is pretty minimal compared to ceiling and walls anyway. 
If you're installing it yourself, go for something that is easy to handle and install.  Batts are a pain in the rear to put up compared to the aforementioned concertina foil batts, Aircell or similar products, particularly if your spacings are off and have to cut to fit while you're under the house.  Mice will dig into and nest into the batts as well. 
In regards to the termite inspection, from what I've seen of termite eaten wood you can't always tell by looking, but obvious when you tap the timber. So not being able to see the sub-floor easily isn't a major issue if you're getting under there tapping and listening.

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## HouseOB

I will look into the price /sqm of the Concertina stuff and batts again, if there isn't much difference will definitely choose the easier option.

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## ChocDog

> I used these Concertina FOIL BATTS - foil insulation - main page

  We used the same. There is some more info with pics, prices, etc in my go-to-whoa thread. Supplier was Lamcal in Heidelberg.

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## FelixTheCat

I used FoilBoard 10, doing about 100 sqm of flooring.  I did some trials before and after, and in winter i got a 2.5 to 3.5 degree floor temperature increase (which i was trying to do because i had a baby that basically lived on the floor).  I was measuring with IR Thermometer.
The unforeseen benefit was in summer.  I have a section of floor that has too much piping, so i didn't insulate there.  I haven't measured the results, but i'd say that it'd be 5 degrees cooler where i have insulated.

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## goldie1

If you have 400 clearance under your floor you can still inspect for termites as their mud trails will  
be visible going up the stumps. Make sure your base boards are not in contact with the ground. 
Over time soil and garden beds can build up on your base boards.

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## ausdesign

Climate zone 6, which is melbourne area generally, requires a total (downwards) R value of 2.25. An open subfloor has a thermal value of approx. 0.5 & an enclosed space a value of around 1.0. A lot of manufacturers quote total R values so you need to make sure the added insulation is sufficient. If you've had a Thermal Assessment done the assessor may have beefed up the floor requirements to compensate for other insulation levels.

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