Topic: concrete floor insulation

concrete floor insulation 

Any suggestions of how to best insulate a concrete floor. Whats the best material to use.
Thanks

Re: concrete floor insulation 

Alice

Existing floor? Difficult, good quality underlay and carpet are probably your most cost effective option. If its a major renovation put batten the floor and then lay say 25mm polystyrene on the slab and then put a timber floor on that. The problem is all your doors and skirting, you would need to remove and re-attach or replace the skirting. For the doors you could remove some of the top and bottom of them and rehang them as shorter doors or you could strip out all of the frames and raise them as much as possible. You will often find a 20-30mm gap between the door frame and the wall frame
lintel.

New floor, easy - 50mm or preferably 100mm of polystyrene below the slab before it is poured also some edge insulation up the sides of any exterior foundation walls that contain the slab. Also ideal opportunity to future fit for underfloor heating if desired. You'll find lots of posts on this subject on here.

Pete

Re: concrete floor insulation 

thanks for that
Its for a new house.
would you know what the R ratings are for 50 mm and 100 mm Ploystyrene. thanks

Re: concrete floor insulation 

Have a look at http://www.design-navigator.co.nz/CRC.php

Select floors and then Slab floor in the drop down menu and have a play.

50mm poly about R1.3, 100mm double that

Pete

Re: concrete floor insulation 

Check out the Max Superfloor at www.maxsystem.co.nz for a fully insulated slab solutio

Re: concrete floor insulation 

thanks for that
send them an email but no reply will try to call them

Re: concrete floor insulation 

The only concern with ploystyrene is that it is not 100% moisture proof. Any puncture in the vapour barrier and over time it will absorb moisture and thus loose it's insulating properties in that place.

A urethane closed cell foam is better and also is made with T&G joints to prevent vertical gaps. Most building material suppliers should be able to source it for you.

Re: concrete floor insulation 

Hi REguy
>>A urethane closed cell foam is better and also is made with T&G joints to prevent vertical gaps. Most building material suppliers should be able to source it for you.

This stuff is virtually unobtainable in NZ, the only place that sells it is Forman Insulation (rigid PU foam), and its very expensive. There used to be a couple of other suppliers 2 years ago that sold it in sheets at various thickness's at much cheaper prices, but they no longer make it.

I would appreciate a link to where one can purchase it in NZ.

Re: concrete floor insulation 

From an Architect friend:

Goldfoam, and Composite insulation in Chch import it
http://www.composite-nz.co.nz/dynamicPage.asp?pageID=21

Web page states warehouses in Napier and Chch. Also page calls it Extruded Polystyrene, not urethane as I thought it was, but it is closed cell.

Re: concrete floor insulation 

thanks for contacting us Max superfloor sound like you got a good product

Re: concrete floor insulation 

Have a look at http://www.xtremepolishingsystems.com

Select Concrete Floors to decor your home.

Re: concrete floor insulation 

Have a look at http://www.xtremepolishingsystems.com

Select Concrete Floors to decor your home.

Re: concrete floor insulation 

Have a look at http://www.xtremepolishingsystems.com

Select Concrete Floors to decor your home.