HardiePanel exterior flooring

Good morning, all. I am looking for ideas on how best to implement 1/2" HardiePanel as an exterior floor under a screened porch.

About 400 sf, mostly under cover, on wood joists and T&G plywood subfloor. I need a waterproof membrane on the subfloor because there is occupied basement space below. Here are the methods I am considering:

1. Schluter Ditra with the HardiePanel laid on thinset. Seems expensive to me but the HardiePanel works out at about 62 cents/sf, so maybe it is overall reasonable.
2. EPDM on the subfloor with HardiePanle glued to it. This seems to offer the greatest water resistance because the large roll size means few seams in the membrane. Not real sure how the HardiePanel glue bond will endure.

That's where my ideas run out. Cost is of course a factor but ease of installation ranks high too. I am in Baltimore so seasonal changes will induce considerable movement to the assembly.

Also, if anyone here has used HardiePanel as flooring, please tell how yo think it works. Does it wear well? It was shown in recent dwell feature as an indoor floor and it looks good but I have no idea what sort of traffic it sustains.

cheers,

mordo

I would be surprised if it was durable enough to resist dents from furniture, objects and heels.
I would send an email to them, asking their opinion

http://www.jameshardie.com/builder/helpSupport_contactUs.shtml

Note they do also make a "wet solution" sub floor product called HardieFloor so I would ask about that.

I would  consider EPDM as the waterproof system, on top of which you could lay 2x4 sleepers (without fasteners, so no penetration), then screw your cement board to the sleepers. The weight of the floor would keep it from shifting, but the fact that you have wooden sleepers will let the floor move independently of the waterproofing during seasonal changes. I used Minerit HD as a floor in my laundry room, and it is wearing beautifully. I did seal it with a cement sealer. Let us know what you decide.

   -R.

Good thoughts. I too am suspicious of Hardie Panel's hardness and durability. I may have to buy a piece and do some trials. I think I don't actually mean HardiePanel siding but rather backer board. I have looked at the subfloor product and that is a real possibility. It appears more durable than the backerboard. The backerboard is only specified by Hardie for interior applications.

R, I don't find a ready source for Minerit HD. It also appears to be made in Finland, a lonnnnngggg way from here. So, I can't imagine it being as cost-effective as Hardie Panel. But, where did you find yours?

I have considered putting the floor on sleepers over EPDM. However, I have some framing height and interior floor elevation considerations that may preclude that concept.

I am hoping to have a response to email I sent to the architect that used the Hardie backerboard in an interior application. Here is an image of the installation:

Since my original post, I've done what I should have to begin with - searched this site for cement board flooring posts. I've found plenty of info. A summary:

1. The consensus is that Hardie backer board is durable enough for flooring and that if you can live with or remove the printed nailing spot grid on it, it gives a nice light gray concrete appearance albeit very uniform. The Hardie subfloor panel is nominally 3/4" thick, is T&G and intended for wet installations(good tip, Peter). I will probably use this provided I can get it to take stain.
   
2. Cembonit and Minerit panels will no longer be sold in the US. Concrete Board Fabricators in Louisville is selling its remaining stock. http://www.cbf11.com/
3. I have found what appears to be a suitable membrane for the application I originally posted about. It is called Noble Deck form Noble Products. http://www.noblecompany.com/Products/SheetMembranes/tabid/58/Default.aspx
   

Others pursuing this product may want to verify the statement below. It is my understanding these products are still being sold in the US, just not by the company mentioned.

Previously mordo wrote:

1. Cembonit and Minerit panels will no longer be sold in the US. Concrete Board Fabricators in Louisville is selling its remaining stock. http://www.cbf11.com/

Indeed. A call to CBF clarifies the information.

The panel products are still being sold by CBF however they now have a new name - SIL-LEED. They say they are the same except that some colors in the Cembonit and Minerit brands are gone but new colors are added in the SIL-LEED brand.

CBF still has new old stock of the Cembonit and Minerit in limited quantities. Their site has a stock list of what's left.

http://www.cbf11.com/

Previously Dave C. wrote:

Others pursuing this product may want to verify the statement below. It is my understanding these products are still being sold in the US, just not by the company mentioned.

Previously mordo wrote:

1. Cembonit and Minerit panels will no longer be sold in the US. Concrete Board Fabricators in Louisville is selling its remaining stock. http://www.cbf11.com/

To follow up even further, American Fiber Cement Corporation is still distributing Minerit HD and Minerit LW panels.

http://americanfibercement.com/minerithd.php